# 5.1 audio mixing (why so much .1)?



## gdstupak (Jul 13, 2010)

This is a personal gripe about 5.1 audio mixing (mostly the LFE mixing)(movies and music), this has nothing to do with equipment, but all with the engineering of the mix.

Why is there so much info put into the discrete LFE channel? Back in the 90's when I first started hearing about the new LFE channel, I understood it did 2 jobs, (1) extend the low freq range of any non full range speaker, and (2) add greater emphasis for special effects such as explosions.

Much more than effects is being put into the LFE channel. My biggest gripe is with music playing through the LFE sub. Why music? To me, music should be played through the main speakers, and if the music freq is too low for the speakers, then the AVR should direct that info to the subs.

Here's the experience I have with my equipment. My main speakers are full range JBL towers (12" woofers). These play cleanly and level down just below 40hz. The JBL woofer's sound is better than either of the 2 subs that I have (not that the subs sound bad, just not as good as the JBL). Yes the subs play louder and with more impact, they are great for effects such as explosions. 

Because of this, music sounds better, more natural, coming from the main speakers. On most 5.1 sources (even music concert Blurays) much of the info is recorded onto the LFE channel. Why? 

Music should be recorded onto the main channels, not the LFE channel. The LFE channel should be used for extra emphasis on effects (kinda like the name implies "Low Freq Effects").

Sure I could listen to the 5.1 mix in stereo but I honestly do like to listen to the surround mix (I'm listening to OAR at MSG now and love how the bass guitar was recorded to the center channel, it sounds great!). In the AVR I could turn off the 'sub out' but I shouldn't have to do that, and I do still want the subs to play the freq below 40hz.


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## Guest (Feb 25, 2011)

Depending on the AVR you have, you should be able to bypass the internal crossover and run full range. I've seen that done on Onkyo equipment anyway.

Either way, I suspect your problem is not with the music source having a .1 sub track that is too loud, but that your ARV/setup is cutting all bass past a preset point (80hz maybe) and sending everything else to the sub. With a roll off of coarse. Your sub might be too loud too.

Another option could just be to get a good musical sub.


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## gdstupak (Jul 13, 2010)

If I put all speakers to full, the only content going to the sub is the .1 LFE track.
Correct?



Generic said:


> Your sub might be too loud too.


My sub is level with the rest of the system. There's a difference between a sub being too loud, and info going to the sub instead of the main speakers.


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## gdstupak (Jul 13, 2010)

I do have several recordings that are 5.0 and 5.1, there's a difference.


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## tonyvdb (Sep 5, 2007)

Most music is not intended to be played through surround. It is recorded in Stereo and that is the best way to listen to it. If you choose to use surround processing then all you are really doing is simulating a surround mix but is not the intention of the original recording. SACDs and DVD concerts are the only exception.
Most receivers if they have a pure/direct mode will bypass the sub all together and run the mains "full range". In "stereo" mode you will engage the sub channel and all lows will be directed to the sub as you have selected in the crossover settings. If the bass is too muddy or to loud chances are you dont have the sub set up correctly or not in the best location in the room and that should be done.


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## gdstupak (Jul 13, 2010)

For music I almost never listen with surround processing.
If it's 2 channel cd, I listen in stereo. I like having my subs play the content below 40hz with stereo, otherwise I'm missing alot of content.
If it's 5.1 discrete audio, I listen in 5.1 discrete audio.

Once again about my subs. They do not sound muddy or too loud. But the fidelity of them is not as good as the JBL woofers. With the JBL's, kick drums, bass guitars, bass drums have a more realistic sound.

My original post has nothing to do with processing after the engineer gets done with it.


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## Guest (Feb 25, 2011)

I'm getting confused. So, are you complaining about your sub? You keep talking about your LFE, but then say you listen to music in stereo, but direct 40hz and below to your sub?

Does your AVR have a 40hz setting? What sub are you using and how is it set up?


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## gdstupak (Jul 13, 2010)

If you're getting confused, my main topic is in the first 3 paragraphs. Just read those and skip the description of my personal equipment and settings.
I'm not complaining about my sub attatched to the LFE channel. I'm griping about too much content being recorded onto the LFE (.1) channel (and when I say 'too much' I don't mean it's too loud).


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## koyaan (Mar 2, 2010)

Time was, on SACds the .1 channel was used for height speakers and the bass stuff all ran to the 5 channels for the pre/pro or AVR to sort out. I know Telarc did this for a while. I really don't know if that protacal is still being used, or has been abandoned.lddude:


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## tonyvdb (Sep 5, 2007)

Too much and too loud are really the same thing. I suspect your sub settings are not calibrated properly. I have never had "too much" music sent to the sub it sounds great on my system. Have you checked what the eq of the sub has been set to. I think you may be confused as the .1 channel is not a dedicated mix and is fully dependent on where you have your crossover set at.


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## gdstupak (Jul 13, 2010)

Obviously I'm not explaining 'too much content' well enough. The way I mean it has nothing to do with volume, it has to do with the amount of stuff being played.
Let me try an example.
And I'm at work right now and haven't seen the movie in awhile so I'm just making this up as I go.
Imagine a movie like 'Phantom of the Opera.' Watching the Ballroom scene where there is alot of loud orchestra music playing, then near the end of the scene there is an explosion when the Phantom pops up and loud organ music plays.
To me, this is how the sound should be mixed: All orchestra/organ music should be put onto the main channels, none of it on the LFE channel. Now when the explosion happens, that sound should be mixed toward the LFE channel.
In reality, more than likely, much of the lower freq music from the orchestra and the organ is recorded onto the LFE. If it is, why is part of the music recorded onto the LFE track? The LFE track should just be there to enhance Low Freq Effects such as explosions. 

I hope this makes more sense.


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## gdstupak (Jul 13, 2010)

tonyvdb said:


> I think you may be confused as the .1 channel is not a dedicated mix and is fully dependent on where you have your crossover set at.


The .1 channel is a totally discrete channel recorded by itself on a 5.1 source.
Depending on how your AVR is set up, it may send lower freq to the sub, but that is different than saying that .1 is not a dedicated channel.

Or is this wrong.


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## tonyvdb (Sep 5, 2007)

technically no, the .1 is not a discrete channel. Your AVR or Blu Ray player will manage what is sent to the LFE channel. Otherwise they would just call it 6 channel or 8 channel mixes not 5.1 or 7.1


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## Sir Terrence (Jun 8, 2006)

I am really confused on this post, as I don't think you are putting your words correctly. 



gdstupak said:


> This is a personal gripe about 5.1 audio mixing (mostly the LFE mixing)(movies and music), this has nothing to do with equipment, but all with the engineering of the mix.
> 
> Why is there so much info put into the discrete LFE channel? Back in the 90's when I first started hearing about the new LFE channel, I understood it did 2 jobs, (1) extend the low freq range of any non full range speaker, and (2) add greater emphasis for special effects such as explosions.


This is correct, we are starting off well. 



> Much more than effects is being put into the LFE channel. My biggest gripe is with music playing through the LFE sub. Why music? To me, music should be played through the main speakers, and if the music freq is too low for the speakers, then the AVR should direct that info to the subs.


Now here is were the wheels fall off the wagon. I have never heard "music" coming from the LFE channel...NEVER! I have heard bass guitars, bass pedals, and other "bass" related effects coming from that channel, but not "music"



> Here's the experience I have with my equipment. My main speakers are full range JBL towers (12" woofers). These play cleanly and level down just below 40hz. The JBL woofer's sound is better than either of the 2 subs that I have (not that the subs sound bad, just not as good as the JBL). Yes the subs play louder and with more impact, they are great for effects such as explosions.
> 
> Because of this, music sounds better, more natural, coming from the main speakers. On most 5.1 sources (even music concert Blurays) much of the info is recorded onto the LFE channel. Why?


Here is where you are just plain wrong. Much of the info is NOT coming from the LFE, it is coming from the main speakers themselves. This is on both music and movie soundtrack. The LFE channel is filtered from 120hz and up with PCM(you can move this downward by filtering at 80hz), and the encoders lossless encoders have a default setting of 80hz for the LFE(which can be moved upwards to 120hz). 

Something must be terribly wrong with you bass management circuit if you are hearing anything above 80hz coming from your sub. 



> Music should be recorded onto the main channels, not the LFE channel. The LFE channel should be used for extra emphasis on effects (kinda like the name implies "Low Freq Effects").


Music is recorded in the main channels, and bass can be either in your mains(no LFE or bass management) or in the LFE. I have never heard a concert video(or music for that matter) where most of the energy was in the LFE...NEVER!



> Sure I could listen to the 5.1 mix in stereo but I honestly do like to listen to the surround mix (I'm listening to OAR at MSG now and love how the bass guitar was recorded to the center channel, it sounds great!). In the AVR I could turn off the 'sub out' but I shouldn't have to do that, and I do still want the subs to play the freq below 40hz.


If you bass management setting have everything under 40hz going to the subs, then you should not hear anything from 40hz and above coming from the sub UNLESS there is LFE content. 

I have to strongly believe that you are not putting what you mean in the right words. No mixing engineer worth his salt(or even less) would put all of the information in a recording in the LFE channel. It would sound like , and never get out of the studio. 

For movies, we have standards for mixing content so this never would happen. Now I have heard frequencies higher than 80hz(but below 120hz) coming from my subs(my main front speakers don't use bass management, they handle all of the bass in their respective channels down to 25hz), but that can mean the person who does the encoding forgot to set the encoder properly. 



> Once again about my subs. They do not sound muddy or too loud. But the fidelity of them is not as good as the JBL woofers. With the JBL's, kick drums, bass guitars, bass drums have a more realistic sound.


Your main speakers are in a different location than your subs. It is quite likely your subs are exciting and driving your rooms modes and nodes from the position they are in, and your main speakers are not. This is an acoustical issue, not a mixing issue. 



> I think you may be confused as the .1 channel is not a dedicated mix and is fully dependent on where you have your crossover set at.


This is incorrect. It is a discrete channel just like all of the others. Setting your mains to large or small will have no effect on this channel if a sub is present. If you have no sub, the bass management will cut the input signal 15db's(to keep from overloading the input circuits), split the signals between your front L/R mains, and then boost the signals by 12db's to keep the signal power in balance with the rest of the mix. 



> I'm not complaining about my sub attatched to the LFE channel. I'm griping about too much content being recorded onto the LFE (.1) channel (and when I say 'too much' I don't mean it's too loud).


I really do think you are confused here. :huh:


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## gdstupak (Jul 13, 2010)

That's news to me. I always understood the LFE (.1) was a totally separate channel that was recorded onto a 5.1 source.
So really it's only 5 discrete channels and then the AVR makes up the .1 channel on it's own?

So why are there 5.0 sources and 5.1 sources. They should all just be 5.0.


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## gdstupak (Jul 13, 2010)

Sir Terrance,
Tony said that the .1 channel is not a discrete channel.


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## tonyvdb (Sep 5, 2007)

If you are questioning that the recordings have only certain sounds sent to the .1 channel no that is not how it works. There are people (mostly purests) who have main speakers that will play down really low who dont even use a sub. They can still get everything that goes to the LFE channel by just selecting "no sub" in the menu and running the mains "full range"


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> Now here is were the wheels fall off the wagon. I have never heard "music" coming from the LFE channel...NEVER! I have heard bass guitars, bass pedals, and other "bass" related effects coming from that channel, but not "music"


You are correct I used the wrong term "music," what I hear coming from the LFE channel is the same that you hear. But why is that recorded onto the LFE channel?



Sir Terrence said:


> Here is where you are just plain wrong. Much of the info is NOT coming from the LFE, it is coming from the main speakers themselves. This is on both music and movie soundtrack. The LFE channel is filtered from 120hz and up with PCM(you can move this downward by filtering at 80hz), and the encoders lossless encoders have a default setting of 80hz for the LFE(which can be moved upwards to 120hz).


In my AVR:
I set my surround and center channel speakers to 'NONE'
I set my main speakers to 'FULL'
I set my subwoofer output to 'ON'
I am listening to a 5.1 source.

Now any sound coming from my sub is coming from the discrete .1 channel. Correct?


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> Sir Terrance,
> Tony said that the .1 channel is not a discrete channel.


Your right, and I fixed my response. I thought I read that he said it WAS a discrete channel..my bad!


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## tonyvdb (Sep 5, 2007)

I think this needs to be answered in another new post "Is the .1 channel a discrete channel" or is it a mix of what the crossover settings are set at that decides what is sent to the sub channel.


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> You are correct I used the wrong term "music," what I hear coming from the LFE channel is the same that you hear. But why is that recorded onto the LFE channel?


Bass is often laid in the LFE channel to assist in clarity in the music. If I keep the really deep bass out of the mains, everything in the mains will be easier to hear - as the upper and mid bass frequencies won't be hampered by excessive cone movement of the deep bass. Most woofers in main speakers operate up to 500hz, which means it carries the lower midrange where voices, keyboards, a lot of lower brass instruments have quite a bit of energy. 




> In my AVR:
> I set my surround and center channel speakers to 'NONE'
> I set my main speakers to 'FULL'
> I set my subwoofer output to 'ON'
> ...


In this scenario, only the LFE should be coming from your sub. Your main speakers are handling all of the main channels bass.


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## gdstupak (Jul 13, 2010)

tonyvdb said:


> I think this needs to be answered in another new post "Is the .1 channel a discrete channel" or is it a mix of what the crossover settings are set at that decides what is sent to the sub channel.


There is no question that the .1 channel is a discrete channel (from the 5.1 source) so I don't know of a reason to start another thread on that subject.

You are partially correct that the descrete .1 channel MAY be mixed with low freq info from other channels. It depends on how you set the crossovers in your AVR.


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## Kal Rubinson (Aug 3, 2006)

tonyvdb said:


> technically no, the .1 is not a discrete channel. Your AVR or Blu Ray player will manage what is sent to the LFE channel.


I am afraid you are wrong about this. The LFE channel is a discrete signal on X.1 channel recordings, although it may have been derived from other channel feeds in the studio, and it is normally sent to the subwoofer. In addition, the AVR or player can institute bass management to divert bass from the main channels to the subwoofer (not the LFE channel), if you choose.

Similarly, if you set the AVR/processor to "No SuB" and set all channels to "Large," many will send the LFE information to the main channels but not all will do so.

The real issue here, and it is somewhat a semantic one, is whether there are unique signals in the LFE channel that are not shared with the main channels. This will vary from recording to recording and is handled somewhat differently in movies vs. MCH music. Nonetheless, if you have an X.1 source, that .1 is, _de facto_, discrete as you receive it.



> Otherwise they would just call it 6 channel or 8 channel mixes not 5.1 or 7.1


The reason is that, originally, for DD/dts, there were bandwidth issues and the additional channel was bandwidth-limited to 120Hz. Only with newer media/codecs that do not have the bandwidth problem can that be a full-range channel, as Telarc, Chesky and others did on SACD and DVD-A (and some were called 6 channel or 2+2+2).


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## gdstupak (Jul 13, 2010)

I think you're all starting to understand my ramblings a bit better now.

Here's another example using music:

I have a 5.0 concert recording where all sound is sent to the 5.0 main speakers, no LFE.
On this recording the engineer put the kick drum in the main left/right channels. It really moves the JBL woofers and sounds very accurate.

I have a different 5.1 concert where the engineer put most of the kick drum on the LFE channel.
Now when the bass drum hits, the JBL woofers are not in action but the sub attatched to the LFE channel really hits. This is not because of the AVR, this is because the sound engineer recorded it to the LFE channel. Please remember this part: it still sounds very good coming from the sub (there is no mudiness and it's not overly loud, it's just not as accurate sounding as the JBL's), but it sounds more refined and detailed when coming from the JBL woofers.

That last example is the part that I have a gripe about. I believe the whole musical spectrum should be recorded to the 5.0 channels, and leave the .1 channel for explosions and such.


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> Bass is often laid in the LFE channel to assist in clarity in the music. If I keep the really deep bass out of the mains, everything in the mains will be easier to hear - as the upper and mid bass frequencies won't be hampered by excessive cone movement of the deep bass.


This makes sense and is a direct response to my original query of why engineers put some musical 'sounds' in the LFE channel.


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> I think you're all starting to understand my ramblings a bit better now.
> 
> Here's another example using music:
> 
> ...


Keep in mind, your sub is probably in a different location than your mains. So how the bass coming from each speaker system interacts with the room modes and nodes will be entirely different. They are not going to sound identical whether the drivers are of equal quality or not. Speakers located near walls will have a totally different sound than speakers 5ft from them, even if they are the same speakers. 



> I have a different 5.1 concert where the engineer put most of the kick drum on the LFE channel.
> Now when the bass drum hits, the JBL woofers are not in action but the sub attatched to the LFE channel really hits. This is not because of the AVR, this is because the sound engineer recorded it to the LFE channel. Please remember this part: it still sounds very good coming from the sub (there is no mudiness and it's not overly loud, it's just not as accurate sounding as the JBL's), but it sounds more refined and detailed when coming from the JBL woofers.


This is an issue with the end users system, not the recording or the recording engineer. A studio speaker system will definitely sound different than your speaker system in your home. I would say that 90-95% of concert video's where mixed on high quality 5.1 sub/sat systems, where all the bass was coming out of the sub. That is going to sound different from a system where the l/R mains are set to large, and you have a subwoofer playing as well. In your system it is apparent that the resolution of the bass in the mains is better than what you get from your subs. In the studio that is not the case, because the mains are most likely NOT playing deep bass. 



> That last example is the part that I have a gripe about. I believe the whole musical spectrum should be recorded to the 5.0 channels, and leave the .1 channel for explosions and such.


Are you saying that you want audio engineers to mix so that it sounds good only on your system, in your room, with your ears??? Work with me here; most studios are not large enough to accommodate large full range speakers that play accurately to 20hz with low distortion at high levels. Not everyone has the room in their homes to accommodate five large full range speakers capable of high output to 20hz with low distortion. So why mix on a system that cannot be accurately reproduced by all kinds of speaker configurations? 

My subwoofers do not have the issues yours does, so why should I not have the LFE coming from that speaker when the audio engineer wants to put it there? It is clear that subwoofers handle bass much better than most main speakers do, so why not mix with that reality in mind? Limiting mixing to what YOUR speakers characteristics is not smart, realistic, or desirable. It is too limiting, and only a few studios in the world would be able to do it.


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## Sir Terrence (Jun 8, 2006)

> The reason is that, originally, for DD/dts, there were bandwidth issues and the additional channel was bandwidth-limited to 120Hz. Only with newer media/codecs that do not have the bandwidth problem can that be a full-range channel, as Telarc, Chesky and others did on SACD and DVD-A (and some were called 6 channel or 2+2+2).


Just to add just a bit to Kal response. Not only was the LFE bandwidth limited, but it also had only one purpose. That was to give the system more headroom in the bass frequencies. So the fact that it is band limited to frequencies under 120hz is not really a problem - it meets the purpose to which it was designed. Now that we have codecs with a lot more bandwidth(the LFE can be full range), we still filter out bass frequencies above 80hz(or 120hz) out of that channel. Full range or not, it still has just one purpose.


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## Trick McKaha (Oct 7, 2009)

I too prefer the musical quality of bass from my mains more than what I get from my subs. Do want to point out that bass info from the main channels can get added to the LFE and sent to the sub even if your speakers are set to "full." It can happen with auto EQ resetting the crossover points after you set the speakers to "full".

I see the OP elaborated and indicated that sometimes the music comes out just right, so maybe it does boil down to how the music gets mixed, and not to the crossover settings in the receiver. If so, I agree that I want the bass sent to the mains, and to all 5 or all 7 in a surround mix, thank you.


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> Are you saying that you want audio engineers to mix so that it sounds good only on your system, in your room, with your ears???
> My subwoofers do not have the issues yours does, so why should I not have the LFE coming from that speaker when the audio engineer wants to put it there? It is clear that subwoofers handle bass much better than most main speakers do, so why not mix with that reality in mind? Limiting mixing to what YOUR speakers characteristics is not smart, realistic, or desirable. It is too limiting, and only a few studios in the world would be able to do it.


This is what I was thinking, if the full music specrum was mixed to 5.0, then it would work well for both systems.
For full size speaker systems, the full content is ready to play on those big speakers
For sat/sub systems, the AVR would direct the lower freq to the sub.

I know I'm just griping and wishing. It wasn't supposed to turn into this big ordeal.


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## gdstupak (Jul 13, 2010)

Trick McKaha said:


> I too prefer the musical quality of bass from my mains more than what I get from my subs.


So according to these guys, your sub must suck or is set up improperly.

....just kidding!!!


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## gdstupak (Jul 13, 2010)

Trick McKaha said:


> I see the OP elaborated and indicated that sometimes the music comes out just right, so maybe it does boil down to how the music gets mixed, and not to the crossover settings in the receiver. If so, I agree that I want the bass sent to the mains, and to all 5 or all 7 in a surround mix, thank you.


It usually comes out great.
I was listening to both of the 5.0 and 5.1 concerts this moring and marveled at how great they both sounded, but was also curious as to why there was so much LFE content (in the 5.1 source only) for music.
At the end of them I just wondered what the 5.1 source would've sounded like if it were mixed as 5.0.

And as I've mentioned in other threads, proper mixing has alot to do with how it sounds. Especially regarding the stereo signal. If mixed correctly I can watch a movie in stereo (no center speaker) and you would swear that the center speaker is playing. Then with other movies, the center speaker has to be on to get the sound centered.


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> This is what I was thinking, if the full music specrum was mixed to 5.0, then it would work well for both systems.
> For full size speaker systems, the full content is ready to play on those big speakers
> For sat/sub systems, the AVR would direct the lower freq to the sub.
> 
> I know I'm just griping and wishing. It wasn't supposed to turn into this big ordeal.


When content that is mixed for speakers away from walls(a 5.0 system) is played back by a speaker sitting near a wall(a subwoofer), it changes the frequency response of the mix in the bass. When you take a track that was mixed for a sub/sat system, and spread it to a full range system, it will do the same. This is one limitation on your idea. 

Secondly, you need a big mixing room(like mine) to have 5 full range speakers to mix through. Most studios are not that big, and there are very few that are. It takes a big speaker to reproduce the 20-20khz frequency spectrum, play it back at realistic levels, and with low distortion. I would guess your system would not even fall in that category, so why require something that only a few can play back accurately? This does not makes much sense, and is the second limitation of your idea. 

Acoustically speaking, having bass coming from all directions in the room ensures that you are going to get a different frequency response from each speaker. Each speaker will be driving the rooms nodes and modes differently, which will result in different bass performance from each of them. A system with 5 full range speakers requires equalization that is different for each speaker, which is very complex to do. It is also unnecessary when one sub will play playback with a flatter frequency response than 5 woofer spread in a ITU-775b configuration(which is the standard mixing speaker setup). Is the average enthusiast going to go through all that trouble just to playback a 5.0 mix natively? I think not, and that is why bass management exists. 

Once again, my system(s) do not have the same issues as yours have. The bass that comes from my subs is exceptionally tight and powerful, so why should it be left out of the mix if I really need it?

Griping and wishing is cool, but asking these questions does help doesn't it? Sometimes we don't know the pitfalls of our ideas until we get them out there for feedback. That is how I learned 50% of my mixing knowledge. I advanced an idea, and got feedback about what I can and cannot do in the studio so it plays back accurately in the field.


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> Griping and wishing is cool, but asking these questions does help doesn't it?


I'm sure more than just I appreciate the time you take to set our wishful notions aflame.


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> I'm sure more than just I appreciate the time you take to set our wishful notions aflame.


I hate being the one that does this....I'll call the fire department:bigsmile:


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> ...I'll call the fire department:bigsmile:


He does have a sense of humor.
...................

Most of this thread got sidetracked more toward trying to explain my original post and the difference between the LFE channel and the sub output. Also mainly focused on music, but I'm also curious about the LFE channel for movies as well.

In my DVD collection it seems that older DVD's (movies from the beginning of the 5.1 Dolby Digital age) are more reserved in their LFE channel use. And newer movies keep putting more and more content onto the LFE channel. Many times when I watch the older DVD's, I'm relieved to hear a more restrained and sensible (to me) soundtrack where I'm not being bombarded by bombastic LFE content for 90-180min.

1. Has increased use of the LFE channel been happening or is it just that my limited DVD collection makes it seem so?

2. Sir Terrence, you mentioned that many (most) engineers are using sat/sub systems. For the engineers that do use full range (or mostly full range) speakers, is there a trend that most of them are switching over to the sat/sub systems since that is what is more popular at this time?

3. Do most engineers use the same speaker setups when mixing 5.1 content and 2.0 content? Mostly I'm wondering if an engineer that is mixing a 2.0 CD uses a sat/sub combination, or do they use 2 full range speakers?


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> He does have a sense of humor.


Yep, it is buried down there below my technical anality!
...................



> Most of this thread got sidetracked more toward trying to explain my original post and the difference between the LFE channel and the sub output. Also mainly focused on music, but I'm also curious about the LFE channel for movies as well.
> 
> In my DVD collection it seems that older DVD's (movies from the beginning of the 5.1 Dolby Digital age) are more reserved in their LFE channel use. And newer movies keep putting more and more content onto the LFE channel. Many times when I watch the older DVD's, I'm relieved to hear a more restrained and sensible (to me) soundtrack where I'm not being bombarded by bombastic LFE content for 90-180min.


When DD 5.1 first came to the theaters in 1993, theater subwoofers(and post production stages as well) were not quite as large as they are now, and they didn't use so many of them as well. A lot of the speaker systems were older, and could not take the amount of bass we are putting into the LFE channel now. We were very conscious about putting in copious amounts of bass into the LFE for fear of blowing drivers out, so we were much more conservative about the levels of bass in the mix. Now most theaters use at least two to four clustered 18" ported subs(and sometimes more), so now we can drive those buggers to the hilt:devil:




> 1. Has increased use of the LFE channel been happening or is it just that my limited DVD collection makes it seem so?


No, the LFE channel is getting louder and louder, and I predicted it would a decade ago when the Hollywood post production community began installing more(4-6) larger subs(18" as 15" inchers were replaced) on their dubbing stages. I knew the theaters would have to follow suite, and it would eventually all of this would end up on our home video media. 



> 2. Sir Terrence, you mentioned that many (most) engineers are using sat/sub systems. For the engineers that do use full range (or mostly full range) speakers, is there a trend that most of them are switching over to the sat/sub systems since that is what is more popular at this time?


I don't really see that trend. Some audio engineers marry themselves to particular types of speakers, and rarely divorce until it become absolutely necessary. For multichannel music(mostly) and film sound tracks meant for the home, we almost exclusively use sub/sat systems for mixing. At Disney(and Mi Casa which does HT mixes for Warner) we exclusively use Genelec monitors and subs in hometheater size rooms to make sure the mixes translate well to most all hometheaters in the field. Mi Casa uses dual custom made 15" subwoofers using JBL drivers. Mi Casa did the hometheater mixes for the Lords of the Ring series of movies, and you know the mixes of those movies have very potent LFE levels. 



> 3. Do most engineers use the same speaker setups when mixing 5.1 content and 2.0 content? Mostly I'm wondering if an engineer that is mixing a 2.0 CD uses a sat/sub combination, or do they use 2 full range speakers?


In the two channel arena, 2 full range speakers rule the roost. Since there is no LFE channel, there is little reason to use a subwoofer. Musical instrument's bass frequencies stop at 42hz for the bass guitar, and most fill range speakers can reproduce that. If you are recording a pipe organ spectacular, a subwoofer is probably used so you can monitor the lowest frequencies of that instrument - that is unless you are using Dunlavy SC-V's like I do.


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## gdstupak (Jul 13, 2010)

Sir Terrence said:


> Mi Casa did the hometheater mixes for the Lords of the Ring series of movies, and you know the mixes of those movies have very potent LFE levels.


Great job on those. I can't wait to listen on the Blurays. Is the audio being remixed for the Blurays, or are they exactly the same as the DVD mixes?



Sir Terrence said:


> In the two channel arena, 2 full range speakers rule the roost. Since there is no LFE channel, there is little reason to use a subwoofer. Musical instrument's bass frequencies stop at 42hz for the bass guitar.... If you are recording a pipe organ spectacular, a subwoofer is probably used so you can monitor the lowest frequencies of that instrument


My mom is a pipe organ player, powerful stuff. At home I listen to a bit of organ and symphonic music, and I don't have Dunlavy's, so I usually use my sub to fill in below 40hz.

--

Ok, probably last question regarding recording/mixing studio's. 
This is about speaker frequency response. Surely all pros try to use equipment and set up equipment that will reproduce a proper frequency response. 
Is there a standard that needs to be met, and if so, is it basically a flat response or some type of curve?
Can electronic EQ equipment be used, or is that taboo?


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## WooferHound (Dec 8, 2010)

gdstupak said:


> In my AVR:
> I set my surround and center channel speakers to 'NONE'
> I set my main speakers to 'FULL'
> I set my subwoofer output to 'ON'


I think you have your system set-up incorrectly . . .
Seems like your main speakers set for Fullrange , which you say go down to 40 hz. Then you have your subs set at a crossover point above 40 or 50 hz. If your crossover were set to 80 hz then your main and sub speakers would be both reproducing sound in the 40 to 80 hz range which is doubling it and causing it to sound bass heavy at times.

You should let the AVR do it's job, letting the crossover divide the sound at a single crossover point so that some of the content is not produced by both the mains and the subs.

I too was also under the impression that the mixes were produced in 5.0 surround and the crossovers in the AVR produced the sub content according to your settings.


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## gdstupak (Jul 13, 2010)

WooferHound said:


> I think you have your system set-up incorrectly . .


The set up you saw is not normally what I use. That was to describe how it's set up if I want to hear just the LFE channel alone.

Normally:
My center/surround speakers are set to 80hz.
My L/R speakers set to 40hz (they actually go lower but I want to take a little load off of them).
My subs trail off above 80hz.

I'm the one that does understand that the LFE channel is discrete on 5.1, but there are mixes out there that use 5.0 and I like that best for music.


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## gdstupak (Jul 13, 2010)

Maybe techie people like Kal or Sir Terrence can help out with my terminology.

Originally I was saying that there is "too much info/content put onto the LFE channel" (and yes I know this comment is purely subjective).
At first most here thought I was saying the 'volume' coming from my sub was too loud. I hope now it is understood that I was not commenting on the amount of volume.

Can someone give me better terminology to describe the difference between 'too much content' and 'too loud of volume?'

Sir Terrence already helped me to understand I didn't mean that I was hearing 'music' from my sub, I should've written 'sound.'

'A better world through better communication.'


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## gdstupak (Jul 13, 2010)

WooferHound said:


> If your crossover were set to 80 hz then your main and sub speakers would be both reproducing sound in the 40 to 80 hz range which is doubling it and causing it to sound bass heavy at times.


Since the main L/R channels and the LFE channel are each discrete, the only way the 40-80hz range would be 'doubled' is if the audio engineer put the same info on all the channels, so in that case it would be proper to be 'doubled.'
If the engineer only put something on the L/R channel at 60hz and nothing on the LFE channel, then it would only be reproduced with the L/R speakers, not with the sub, and that would be proper.

There is a setting on my AVR that lets me 'doublebass,' which does combine the L/R output with the sub output.
I have used this setting in the past and anytime I do, I equalize the whole system so that the mains and sub are still balanced. I do not like a bass heavy set up, I like it to be flat (ok, I add a few db's when it gets below 80hz for a little more feeling).


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## Kal Rubinson (Aug 3, 2006)

gdstupak said:


> Maybe techie people like Kal or Sir Terrence can help out with my terminology.
> 
> Originally I was saying that there is "too much info/content put onto the LFE channel" (and yes I know this comment is purely subjective).
> At first most here thought I was saying the 'volume' coming from my sub was too loud. I hope now it is understood that I was not commenting on the amount of volume.
> ...


First, you should be careful to distinguish between LFE signals and subwoofer output since the former is defined by the source material you are playing and the latter by that plus the redirected LF from bass management.
Second, volume/loudness is varied by level controls but LFE content is determined by range of signals that the recording/mixing/mastering engineers put into the LFE channel and subwoofer content is determined by that plus the results of bass management.


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## gdstupak (Jul 13, 2010)

Kal Rubinson said:


> First, you should be careful to distinguish between LFE signals and subwoofer output since...


I guess that's why in my original post I kept writing "LFE channel" over and over, not subwoofer output.
My point was about the LFE channel content, not the subwoofer content. But somehow I kept getting bombarded with suggestions that my system was set up incorrectly, or my sub wasn't good enough, or too loud.


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> Maybe techie people like Kal or Sir Terrence can help out with my terminology.
> 
> Originally I was saying that there is "too much info/content put onto the LFE channel" (and yes I know this comment is purely subjective).
> At first most here thought I was saying the 'volume' coming from my sub was too loud. I hope now it is understood that I was not commenting on the amount of volume.
> ...


Let me help you out here....pull up a chair and get out your notepad. 

If I were going to ask your question again, I would ask this; why are audio mixers using the LFE for concert videos? There is no real deep bass effects in music. That simple question would have gotten this answer...because it reduces the cone movement coming from the main speakers, which gives additional clarity to the mid and upper frequencies, and assigns the bass to the speaker best capable of handling it. 

Loudness refers to the volume of the signal coming into a particular channel. Too much content means the mix is too dense which effects clarity. You can have a loud channel with just one effect, and you can have a soft channel with too many effects. 

I hope this helps you out sir. Now back to our regular question and answer session:nerd:


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## Sir Terrence (Jun 8, 2006)

gdstupak said:


> I guess that's why in my original post I kept writing "LFE channel" over and over, not subwoofer output.
> My point was about the LFE channel content, not the subwoofer content. But somehow I kept getting bombarded with suggestions that my system was set up incorrectly, or my sub wasn't good enough, or too loud.


Manufacturers have not help things one bit by labeling their subwoofer output the LFE output. The LFE channel is not married to the subwoofer, it can exist even if there is no subwoofer. The LFE is in the software, the subwoofer output is in the hardware.


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## gdstupak (Jul 13, 2010)

Thanks to Kal and Sir Terrence.


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## Joris (Apr 8, 2011)

gdstupak said:


> There is no question that the .1 channel is a discrete channel (from the 5.1 source) so I don't know of a reason to start another thread on that subject.
> 
> You are partially correct that the descrete .1 channel MAY be mixed with low freq info from other channels. It depends on how you set the crossovers in your AVR.


In Film, the.1 is sometimes treated as discrete for Sound-design 'in the head' of the designers but on
the mixing console in final mix there is nothing such as a special routing to that channel indeed.


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## harckan (Apr 11, 2011)

Thank's for all posts, this is very important for me.

Regard


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Much more than effects is being put into the LFE channel. My biggest gripe is with music playing through the LFE sub. Why music? To me, music should be played through the main speakers, and if the music freq is too low for the speakers, then the AVR should direct that info to the subs.


Correct.



> Here's the experience I have with my equipment. My main speakers are full range JBL towers (12" woofers). These play cleanly and level down just below 40hz. The JBL woofer's sound is better than either of the 2 subs that I have (not that the subs sound bad, just not as good as the JBL). Yes the subs play louder and with more impact, they are great for effects such as explosions. Because of this, music sounds better, more natural, coming from the main speakers.


If the subs don't sound as good as the mains, then it would be worthwhile improving the sub setup. They should sound better when you're done. 



> On most 5.1 sources (even music concert Blurays) much of the info is recorded onto the LFE channel. Why? Music should be recorded onto the main channels, not the LFE channel. The LFE channel should be used for extra emphasis on effects (kinda like the name implies "Low Freq Effects").


Let's set aside movies--they have to use LFE since there's no bass management in cinemas. But you ask a perfectly good question about non-cinematic content. The answer is there is no good technical reason to use LFE. It is mainly fashion and preference. And the fact that consumers will actually brow beat music mixes if they are "only" 5.0. :hissyfit:

Also, be advised that for various unfortunate reasons, there is a lot of 5.1 music out there with improperly mixer or mastered LFE signals. Either they are too loud (due to poorly calibrated mixing rooms) or due to a spurious alternative LFE calibration standard that wants LFE played without the 10 dB gain, or because they failed to bandlimit the LFE channel properly to 80 Hz. Quite sloppy on the whole, but of course there are also well made recordings, too.



Sir Terrence said:


> Let me help you out here....pull up a chair and get out your notepad.
> 
> If I were going to ask your question again, I would ask this; why are audio mixers using the LFE for concert videos? There is no real deep bass effects in music.


There can certainly be deep bass in music. And since the LFE channel goes no deeper then the main channels, that would hardly be a way to deliver deeper bass if that were the goal.



> That simple question would have gotten this answer...because it reduces the cone movement coming from the main speakers, which gives additional clarity to the mid and upper frequencies, and assigns the bass to the speaker best capable of handling it.


The mixing engineers should not try to perform bass management in the content. That is sheer folly, totally unnecessary, and only degrades the quality of the recording by adding additional filters and phase shift. Bass management is best handled in the playback system.


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## gdstupak (Jul 13, 2010)

Roger, thank you for your comments, they were well written. You obviously understand the points I was trying to convey and I am happy that there are others that think the same as I do about this.
Just because many people have main speakers that can't handle the lower frequencies of bass guitar, doesn't mean that the bass guitar should be mixed into the dedicated LFE channel. The bass guitar should be put into the main speakers and if your speakers can't handle the bass, then the AVR should put it into the subwoofer.
And yes there is a lot of music with sub bass frequencies, anyone saying there isn't just isn't listening to classical music properly.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> If the subs don't sound as good as the mains, then it would be worthwhile improving the sub setup. They should sound better when you're done.


I don't think it's really a matter of improving my sub setup, it's a matter of changing the type of subs which would be less exciting with movies.
Subs that are associated with traits that are good for accurate music reproduction usually have a lower Q factor. Subs that are associated with traits that are good for movie rumblings usually have a higher Q factor. 
10yrs ago when I was considering which speakers to buy, all my music listening was 2ch. So I bought main tower speakers with bass drivers that played music more accurately. Since the outboard subs would be playing mainly LFE content, I wanted subs that had a little bit of the rumble factor for movies. So I picked subs that had a middle-of-the-road Q factor that would be good for both music and movies. 
This combo works very well for 2ch music and 5.1 movie watching. Well, lately I've been getting into 5.1 surround music and have been noticing instruments placed in the LFE channel. 

I am currently in the process of updating my sub setup. It will be an IB manifold in the living room ceiling, with a pair of Fi IB3 18's. Hopefully this will give me proper musical SQ while still maintaining enough rumble to satisfy me for movies. We'll see.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> I don't think it's really a matter of improving my sub setup, it's a matter of changing the type of subs which would be less exciting with movies.
> Subs that are associated with traits that are good for accurate music reproduction usually have a lower Q factor. Subs that are associated with traits that are good for movie rumblings usually have a higher Q factor.


Could you explain more about Q factor? I have not seen that mentioned in the Welti/Toole papers on subwoofers.

I did not think accuracy in sub performance would be bad for movies. It does not seem to hurt them in my case. 



> 10yrs ago when I was considering which speakers to buy, all my music listening was 2ch. So I bought main tower speakers with bass drivers that played music more accurately. Since the outboard subs would be playing mainly LFE content, I wanted subs that had a little bit of the rumble factor for movies. So I picked subs that had a middle-of-the-road Q factor that would be good for both music and movies.


How do the sub makers express Q factor in the specs? And what do you mean by rumble factor? Is that max SPL output capability?


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## gdstupak (Jul 13, 2010)

Q is listed as a T-S parameter, generally expressed as a number between 0.3 and 0.9.
My previous mention of Q was a very broad generalization, in reality it is a very complex subject matter. A subject which my little brain can not explain off the top of my head.

There is nothing wrong with having accuracy in subs for movies, personally this is my preference. But to make another very general statement about Q, many people like a higher Q for movies because they have less dampening factor and accentuates certain sounds (frequencies) which make explosions and gunshots more explosive feeling.

I just got home from work and need some sleep. I will work on posting up some links on Q later. Maybe someone more techie will chime in also.


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## gdstupak (Jul 13, 2010)

Some informative links:
As you read these, keep in mind that woofer drivers have a Q parameter and the driver/enclosure also have a Q parameter. The Q of the driver, once installed into a cabinet will change depending on the enclosure type and size. If you have a .4 Q driver, more than likely, the driver/enclosure will have a higher Q. Q of a driver can always be raised, but never lowered.

"What do the driver T/S parameters mean... " http://www.speakerplans.com/index.php?id=faq1

"Smart Q" http://www.rythmikaudio.com/smartQ.html

"How to choose the correct speaker" http://www.loudspeakersplus.com/choosing_the_correct_speaker.html

There is one other I am looking for but can't find it at the moment.


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## Roger Dressler (Aug 1, 2009)

Thanks for the informative posts. The "What's all this Q stuff" post ties the Q parameter to actual sonics. He says: 



> What many 'box' sub designers fail to take into consideration, is that *room gain will change the characteristic of these 'Q's*. So starting off with a 0.707 sounds good in theory. But when placed in the room, the sub may tend to sound a bit bloated in the midbass given the boost from room gain.





> The standard thinking is that open baffle/dipole/IB drivers should have a Qts around 0.69. And companies make drivers targeting that specific Qts. My thinking is that for IB subs and for box subs, this is too high a 'Q', *unless one want's the added 'boom' when room gain is factored into the picture*.





> Finally, people ask about 'music' only subs vs HT subs (more confusion generated mostly by marketing). I don't think this differentation should exist. A good sub is a good sub. *It's no problem to take a 'music' sub (typically low Qtc), dial in a slightly different EQ curve and have a great sub for HT use*....


 What I take from all this is that when a sub's in-room response is dialed in for highest accuracy (smoothest response), the inherent distinctions between high and low Q drivers or boxes disappears. Inaccurate sound can be more exciting (more boom, etc), so I would not stop anyone from doing that if it's their preference. But I do not think we can automatically assume those high-Q traits are automatically "good for movies."


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## gdstupak (Jul 13, 2010)

Remember, you can always lower the Q of a sub, but never raise it.
There is much more to Q than it's frequency response. 2 subs can be measured perfectly flat, but one might have tight bass and one might have loose bass. My system has multiple equalizers, I can eq both outboard subs and the JBL's woofers to have the exact same frequency response, they all still sound different. 
This is also true for standard speakers. I can eq my JBL's, Bose, and DCM's to have the exact same frequency response, but each set still sounds different.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Remember, you can always lower the Q of a sub, but never raise it.


The issue is not the Q in free space, but in the room. The first quote in my previous post clearly stated that rooms can make subs sound boomy, same as a high Q sub. One must address the whole system, not the sub alone.



> There is much more to Q than it's frequency response. 2 subs can be measured perfectly flat, but one might have tight bass and one might have loose bass. My system has multiple equalizers, I can eq both outboard subs and the JBL's woofers to have the exact same frequency response, they all still sound different.


First, no subs measure perfectly flat. If they sound different, the responses are probably different (among other characteristics like distortion). Maybe you are not measuring the responses with sufficient resolution. Or maybe the subs do not occupy exactly the same physical space, so the room responds differently.



> This is also true for standard speakers. I can eq my JBL's, Bose, and DCM's to have the exact same frequency response...


I doubt it. No EQ can make the direct and power responses of two different speakers match.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> I doubt it. No EQ can make the direct and power responses of two different speakers match.


Ok. 
When I mention speakers having the same frequency response, I'm just talking about simple SPL levels throughout the frequency range, so I guess my SPL meter is lying to me.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> First, no subs measure perfectly flat..


Whether a sub can measure perfectly flat has nothing to do with the point I'm making.



Roger Dressler said:


> If they sound different, the responses are probably different (among other characteristics like distortion).


So if they did have the same frequency response, they would sound identical? You don't believe there are other factors to a systems sound, such as damping? You don't believe a more damped sub can have tighter, more controlled bass than a sub that has less damping, which can cause overhang, ringing, and other sound variations?


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Whether a sub can measure perfectly flat has nothing to do with the point I'm making.
> 
> 
> So if they did have the same frequency response, they would sound identical? You don't believe there are other factors to a systems sound, such as damping? You don't believe a more damped sub can have tighter, more controlled bass than a sub that has less damping, which can cause overhang, ringing, and other sound variations?


I'm saying if the damping is different, not only will the sound be different, but so will the frequency responses. An equalizer, of the right type, when applied appropriately, can mitigate that audible difference. I'm talking about subs only. Have you read Toole's book? I realize I am not able to distill and convey the vast knowledge there. But he addresses these matters quite well.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> I'm saying if the damping is different, not only will the sound be different, but so will the frequency responses. An equalizer, of the right type, when applied appropriately, can mitigate that audible difference. Have you read Toole's book?


I've scanned Toole but haven't seen that, I'll check it out.
But what I have read, damping isn't effected by an EQ. You can have a very loosely damped sub that has the same SPL response as another sub that has higher damping, but the first sub will still have loose damping (and may have inaccurate effects such as overhang, ringing...). 
Being able to play all frequencies at the same SPL level does not mean that you have changed the damping. 
That's what I understand but will check out Toole.


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## Roger Dressler (Aug 1, 2009)

I was talking with Keith Yates this weekend. Maybe you have seen some of his "Way Down Deep" articles for Stereophile. Here's a link to one. I told him of our conversation and asked his opinion. He reported that outside--where there's no room, these subs of course sound different, but neither tight nor loose. These attributes are a result of how that sub interacts with the room -- not the sub itself. Choice of sub certainly matters, it determines response and loudness and the like. But the ability to achieve the desired end result is dominated by how it mates with the room.


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## gdstupak (Jul 13, 2010)

Keith Yates should be able to put out very reliable information, so I shouldn't argue.

But I read an article online this weekend that explains how the sub itself sounds loose or tight, but I didn't know the author's name and I can't recall it, so this could be completely false, but to me it makes perfect sense. He compared the woofer suspension (working along with the driver motor, and the sub enclosure) to the suspension of a car. (The tightness of a sub has more to do with it's suspension than it's frequency response). 
...Take a station wagon with a standard suspension (shocks, leaf springs) and it will bounce along a bumpy road, possibly making the ride a bit erratic if the suspension is loose enough. And once the bumps are gone, the car continues to bounce a bit before settling back to it's smooth riding position. 
...Now take a new sports with a high quality, stiffer suspension and it will be much more controlled over a bumpy road. And once the bumps are gone, the car will settle to it's normal riding position very quickly.

Same for woofers/subs. 
...Take a loose sub and it will not be able to make proper changes with very complex audio signals and it will continue to vibrate for a short time after the audio signal ends (this gives a little extra feeling for those explosions in movies).
...A tight sub will follow changes in the audio signal much quicker, and after the audio signal ends, the sub driver will stop vibrating and return to it's normal resting position much faster (this sounds much more accurate which sounds best for music (and in my opinion this should also be the goal for movie subs because if the sound engineer wants the explosions to have more oomph, he/she should just put it into the audio signal).

Maybe this car to sub comparison is just hogwash from an unreliable source, but it makes sense to me.

And yes, I understand the room plays a huge role in how subs sound (especially frequency response). But from what I've read I also believe tightness has more to do with the mechanical and electrical factors of a sub itself whether it is outside or inside a room.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> And yes, I understand the room plays a huge role in how subs sound (especially frequency response). But from what I've read I also believe tightness has more to do with the mechanical and electrical factors of a sub itself whether it is outside or inside a room.


If that were true, then the changes Floyd Toole describes in his book, about how he a) repositioned his subs in one case, and b) used equalization in an alternative case, both resulted in eliminating the flabby bass and yielded tight bass. No change to the woofer itself.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> If that were true, then the changes Floyd Toole describes in his book, about how he a) repositioned his subs in one case, and b) used equalization in an alternative case, both resulted in eliminating the flabby bass and yielded tight bass. No change to the woofer itself.


I thought of including this statement earlier but was trying not to make my post too long, maybe this fits with Floyd's experience:
I understand you can have a mechanically/electrically tight sub but the room can make it sound very flabby, which could be fixable with eq and placement.
But a sub that is mechanically/electrically loose can be helped only slightly with eq and placement.
My guess is, Floyd was experimenting with subs that had a lower Q value (more accurate suspension,damping,eq) to start with. At anytime does Floyd state that he has taken a mechanically/electrically loose sub and has made it to sound the same as a tight sub?

Hopefully I'm not appearing to be combative here. I'm not an engineer and have hard times understanding much of the more technical aspects to sound, so I'm just taking what I think I understand and am trying to learn.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> I understand you can have a mechanically/electrically tight sub but the room can make it sound very flabby, which could be fixable with eq and placement.
> But a sub that is mechanically/electrically loose can be helped only slightly with eq and placement.


How do you know it cannot be helped? Any evidence to point to? It has to be more than "I put sub A in a room and it sounded much looser than sub b." Unless it is optimized, it really means nothing other than it's not working optimally, and any manner of unfortunate sonic qualities will result. 



> My guess is, Floyd was experimenting with subs that had a lower Q value (more accurate suspension,damping,eq) to start with. At anytime does Floyd state that he has taken a mechanically/electrically loose sub and has made it to sound the same as a tight sub?


Why would anyone want to use a poorly designed sub into a serious AV system? If it is not poorly designed, then what measurement criteria defines it as loose? Maybe people who proclaim one woofer is looser than another is simply not comparing them under the same conditions. Considering that is virtually impossible to do inside a room, I would not be surprised. 



> Hopefully I'm not appearing to be combative here. I'm not an engineer and have hard times understanding much of the more technical aspects to sound, so I'm just taking what I think I understand and am trying to learn.


Not combative at all. This is a very useful exchange to explore these notions of tight/loose and see what is really behind them.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> How do you know it cannot be helped? Any evidence to point to? It has to be more than "I put sub A in a room and it sounded much looser than sub b." Unless it is optimized, it really means nothing other than it's not working optimally, and any manner of unfortunate sonic qualities will result. .


I have no evidence for my points, but have provided a few links that helped to point me in a certain direction. I haven't read anything yet to show that that line of reasoning is wrong(i.e. I have not seen evidence proving that a higher Q can be lowered to be more accurate ...and...the mechanical/electrical suspension system (just like on a car) is a physical characteristic that, if loose, I can't understand how it can be tightened up...and...a more accurate lower Q sub can sound loose and inaccurate because of room effects which usually could be fixed with correct room placement, room treatments, and eq).


Roger Dressler said:


> Why would anyone want to use a poorly designed sub into a serious AV system?


 I have plenty of friends who would rather have the sound of a more explosive sub than one that is more accurate. And again, it's not that it's poorly designed, it has been specifically designed for a certain sound and experience.


Roger Dressler said:


> If it is not poorly designed, then what measurement criteria defines it as loose? Maybe people who proclaim one woofer is looser than another is simply not comparing them under the same conditions. Considering that is virtually impossible to do inside a room, I would not be surprised.


 I have already provided links explaining T/S parameters such as Q. Some of these measurements are mathmatically arrived at. Before a sub system is put together, these factors can tell a person how a sub should sound (loose, tight, punchy...). I don't understand why you believe comparing subs in a room is "virtually impossible." Different subs can be placed either in the exact same locations, or they can be placed in locations that are ideal for that particular sub, then just listen. Terms such as loose, tight, and puchy have certain characteristics that our ears can hear.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> I have no evidence for my points, but have provided a few links that helped to point me in a certain direction. I haven't read anything yet to show that that line of reasoning is wrong (i.e. I have not seen evidence proving that a higher Q can be lowered to be more accurate ...and...the mechanical/electrical suspension system (just like on a car) is a physical characteristic that, if loose, I can't understand how it can be tightened up...and...a more accurate lower Q sub can sound loose and inaccurate because of room effects which usually could be fixed with correct room placement, room treatments, and eq).


The car analogy does not work here. No matter what kind of car you drive on the road, the road remains rigid and unaffected. The human experiences only what happens *inside the car*. 

A subwoofer in a room is a system--they interact, and the human is not inside the sub, nor riding on the driver's cone, he's in the room. Whether the sub is high Q or not does not dominate the acoustic result -- especially when steps are taken to position and EQ that sub for a desired outcome, be that tight, loose, or punchy.



> I have plenty of friends who would rather have the sound of a more explosive sub than one that is more accurate.


They are free to do so. It is not a question of preference. A system can be tuned for whatever taste is desired, just as Toole showed. The point is there is no need to change the sub's Q characteristics to change the overall performance of the system dramatically. 



> And again, it's not that it's poorly designed, it has been specifically designed for a certain sound and experience.


I was just saying that if a sub has so much looseness in the design that one can hear it ringing on long after the excitation has ceased, then that is a poor design. If that is not the case, then we are back to sub/room tuning being the dominant factor in "tight/loose" performance.



> I have already provided links explaining T/S parameters such as Q. Some of these measurements are mathmatically arrived at. Before a sub system is put together, these factors can tell a person *how a sub should sound* (loose, tight, punchy...).


That is the fallacy. They can only be indicative of how a sub will sound anechoically -- like outside in free space. That's why Yates tests subs outdoors. It's the only way to remove the room/sub influence. Put the sub into a room, and it's a whole new ball game.



> I don't understand why you believe comparing subs in a room is "virtually impossible." Different subs can be placed either in the exact same locations,


Unless the two subs are identical in physical construction and dimensions, they cannot be placed in the "exact same locations." Even the simple task of removing one sub and replacing it with another makes human comparison a challenge--memory being what it is. Just determining that the output levels are matched is no easy task (pretty much impossible since the responses *will be different*). Lastly, if one were trying to find "which sub sounds best in this specific location without any other optimizations" I suppose one could undertake that project. I would think that when someone chooses a sub for their home system, they would want to find its optimum performance, and that means tuning it for that room by gross/fine positional adjustments and some judicious EQ. Without that, no one can really say how well any sub performs--as it is tainted by insufficient room/system integration.



> or they can be placed in locations that are ideal for that particular sub, then just listen.


Which locations are those? How does one find them? Trial and error? By what sounds "best" and in whose opinion? With what sources? 



> Terms such as loose, tight, and puchy have certain characteristics that our ears can hear.


Yes. But I thought the issue was whether a particular Q parameter would determine how a sub sounded in a room. I have not yet seen any objective evidence that such is the case, and I have provided objective evidence from experts that such is not the case. I reiterate, Toole, Sound Reproduction, Chapter 13.4-13.5.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> Which locations are those? How does one find them? Trial and error? By what sounds "best" and in whose opinion? With what sources?


 Surely you know how to do the sub crawl. The best sound could be determined by our ears or even test equipment can show what location provides the most desirable (accurate) attributes. 



Roger Dressler said:


> Yes. But I thought the issue was whether a particular Q parameter would determine how a sub sounded in a room. I have not yet seen any objective evidence that such is the case, and I have provided objective evidence from experts that such is not the case. I reiterate, Toole, Sound Reproduction, Chapter 13.4-13.5.


Maybe I'm missing it, but as I stated earlier, I'm not reading Q stats from Toole's experiments. 
What started this was my belief that 2 subs can have the same frequency response (SPL measurements throughout the freq range) but still sound different because the Q is different. You disagreed.

I guess we'll just have to agree to disagree.

And in 2002 I was one of those that chose to build a sub with a middle-of-the-road Q that would be good for movies and music but not the best for either one. I explained why back on post #51.


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## phreak (Aug 16, 2010)

I want to jump in on one small point which seems to be the main point in the conversation. I can take two different acoustic guitars of similar build quality, accurately tune them both, and play the same note at the same level on both. Each will have it's own characteristic sound. A trained ear may even differentiate 2 guitars of the same make/model. Why wouldn't the same be true for a sub? Isn't it basically an acoustic "instrument" with the "strumming" carried out by an electric motor pushing the diaphragm in and out? Identical frequency response when both subs are driven at equal levels at 20 hz may produce different responses between the two at 40, 80, 160 hz overtones. Or I may be out in left field listening to the music in my head with the volume on mute.


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## Roger Dressler (Aug 1, 2009)

phreak said:


> I want to jump in on one small point which seems to be the main point in the conversation. I can take two different acoustic guitars of similar build quality, accurately tune them both, and play the same note at the same level on both. Each will have it's own characteristic sound. A trained ear may even differentiate 2 guitars of the same make/model. Why wouldn't the same be true for a sub? Isn't it basically an acoustic "instrument" with the "strumming" carried out by an electric motor pushing the diaphragm in and out?


No. The speaker diaphragm s following the input waveform, not resonating like an acoustic instrument. That's why a speaker can sound like various guitars, a piano, or a human, all from the same device.



> Identical frequency response when both subs are driven at equal levels at 20 hz may produce different responses between the two at 40, 80, 160 hz overtones.


They may differ, but ideally all those harmonic distortion products would be inaudible.


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## phreak (Aug 16, 2010)

I humbly stand corrected. And I now know more than I did yesterday.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Surely you know how to do the sub crawl. The best sound could be determined by our ears or even test equipment can show what location provides the most desirable (accurate) attributes.


The crawl is pretty much irrelevant to this discussion. It's a way to get a sense of how a sub will interact in a room, but it's not precisely invertible. It might imply different locations for different subs, or it might not. In either case, the responses will differ, and without further optimization, results will be inconclusive.



> Maybe I'm missing it, but as I stated earlier, I'm not reading Q stats from Toole's experiments.
> What started this was my belief that 2 subs can have the same frequency response (SPL measurements throughout the freq range) but still sound different because the Q is different. You disagreed.


If the response measurement is inadequate, it does not mean the responses are the same. If not reflected in the response, what parameter of the acoustic sound is different when the Q is different? 

I'm saying if you put the plump sounding high Q "movie" sub in a room and then swap it out for a lean sounding low Q "music" sub, they will sound different because they have different in-room responses. People choose these subs as a means to tune their system, just as they choose the main speakers for their spectral balance, etc. I take no issue with any of that. 

What I am saying is that, all else being equal, those two subs can be made to sound the same with proper EQ tuning. It's relatively recent in the evolution of subs to have sophisticated EQ measurement and adjustment methods available for the general consumer, less than 10 years. It will take time for that to ripple thru the notions on how one selects a sub and implements it into a system. It's even more recent that using 2, or better yet 4 subs has gained traction as the most effective means to improving the bass in general and moreover improving the consistency of bass across several seats in a room. We can thank Harman/Welti for that. No single sub, regardless of Q or any other T/S parameter, comes close to making that kind of improvement in the result. 



> And in 2002 I was one of those that chose to build a sub with a middle-of-the-road Q that would be good for movies and music but not the best for either one. I explained why back on post #51.


But you do not have any evidence to show that a different Q would have performed differently, and that those differences are due to something other than frequency response. 

What Toole is doing is trying to dispel the many myths surrounding sound reproduction and exposing the actual technical aspects behind it. Anecdotal reports, bromides, rules of thumb, "standard" practices, do not always stand up to deeper investigation. The book is loaded with such examples.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> I'm saying if you put the plump sounding high Q "movie" sub in a room and then swap it out for a lean sounding low Q "music" sub, they will sound different because they have different in-room responses.


As always, I still agree with this statement. Different subs will have different in-room responses.
The Q of the sub will help to shape that in-room response, and subs can be built to have a certain Q.


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## gdstupak (Jul 13, 2010)

Regarding phreak's inquiry about overtones (not harmonic distortion):


Roger Dressler said:


> They may differ, but ideally all those harmonic distortion products would be inaudible.


I understood overtones are very audible and overtones is a major factor which make one instrument sound different from another, whether listening to an actual instrument or listening to those instruments through a speaker.
In other words, the speaker reproduces overtones which is what makes a trumpet sound different from a trombone.

Or maybe this wasn't even the point of the original post?


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## GranteedEV (Aug 8, 2010)

Roger Dressler said:


> No single sub, regardless of Q or any other T/S parameter, comes close to making that kind of improvement in the result.
> 
> But you do not have any evidence to show that a different Q would have performed differently, and that those differences are due to something other than frequency response.


To an extent, you are correct.

However, Q is still very relevant, and why I would never shoot above .65 or so.

Q means the shape of the curve. Obviously, with equalization, you can make any speaker flat as a pancake.

However, low Q also indirectly implies two more things.

1) Internal pressure/reradiation/ringing. You can't just stick a driver in a 2.0 Q box (like many do, mind you), and then EQ it flat, and be guarunteed that there is no internal ringing that might cause muddiness. A Q of .5 or lower also generally means critical damping, and ensures that the returning energy will not be re-radiated.

2) Efficiency. A low Q build, IE infinite baffle, will have more low end efficiency, meaning it will require less power to EQ flat. The result is reduced thermal compression. Heat changes your amplitude response, and general loudspeaker behaviour. It's measurable in a room or out.

Unless you implement advanced servo to the above situations, I still see low Q subwoofers, as optimal, not matter how you plan to EQ their amplitude response at the end of the day.

Cheers.


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## Roger Dressler (Aug 1, 2009)

GranteedEV said:


> To an extent, you are correct.
> 
> However, Q is still very relevant, and why I would never shoot above .65 or so.
> 
> ...


Agreed. I am not saying that poorly designed subs can be fixed with EQ. 



> 2) Efficiency. A low Q build, IE infinite baffle, will have more low end efficiency, meaning it will require less power to EQ flat. The result is reduced thermal compression. Heat changes your amplitude response, and general loudspeaker behaviour. It's measurable in a room or out.


Agreed. I never said that all the other characteristics of subwoofers would disappear with system tuning. That's why I say "all other things being equal." 



> Unless you implement advanced servo to the above situations, I still see low Q subwoofers, as optimal, not matter how you plan to EQ their amplitude response at the end of the day.


Seems perfectly reasonable to me. Thanks for your reply.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Regarding phreak's inquiry about overtones (not harmonic distortion):
> 
> I understood overtones are very audible and overtones is a major factor which make one instrument sound different from another, whether listening to an actual instrument or listening to those instruments through a speaker. In other words, the speaker reproduces overtones which is what makes a trumpet sound different from a trombone.


Correct.



> Or maybe this wasn't even the point of the original post?


No. His thought was that subs are like musical instruments, where notes sustain and decay after being "strummed" by the voice coil.


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## gdstupak (Jul 13, 2010)

Some posters have brought up the idea that maybe a better sub would give me better quality sound, these are my 2 subs:
1) HSU VTF-2
2)diy build: Audio Adire 15" Tempest Sealed Box Mid Q Design (pg6, chp3.2) http://www.thunderpimp.com/subwoofer/SealedTempestApplications.PDF
   

The Adire Audio subwoofer build article notes that the differing 'group delays' of their 3 different builds (low Q, mid Q, high q) is a factor for what 'tightness' each sub may exhibit. Here is their explanation of group delay: http://www.adireaudio.com/Files/GroupDelay.pdf 

Adire Audio mentions group delay is related to frequency response. From this article, I'm not sure if a simple equalizer would be able to change the group delay of these various subs so they would match each other.
Hopefully someone more technically inclined, such as GranteedEV, could elaborate further.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> The Adire Audio subwoofer build article notes that the differing 'group delays' of their 3 different builds (low Q, mid Q, high q) is a factor for what 'tightness' each sub may exhibit.
> 
> Adire Audio mentions group delay is related to frequency response. From this article, I'm not sure if a simple equalizer would be able to change the group delay of these various subs so they would match each other.


The Adire paper states: >>for our purposes, a subwoofer driver operating in a box, in its linear mode is a minimum phase system.<< Toole has explained that minimum phase response errors can be addressed with proper equalization. That may not be achieved by a "simple equalizer" but it can be done with the right PEQ.

With EQ, you might not get the group delays of all the subs to match below 10 Hz where the passive radiator model "goes wild," but no matter, as the responses of these subs are all finished by then.

All of this all supports what I have said. In case you have not bought the Toole book yet, you can read several pages in Chapter 13 at Amazon for free. Click this link, then hover your mouse over the book cover -- do not click. It will open a search window. Type the words "tighter bass" and it will take you to page 239. You can read several pages of relevant material, even though some are not shown.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> All of this all supports what I have said.


That Toole reference does support the notion that group delays can be adjusted with eq.

But to me, this also emphasizes the notion that the sound of the sub itself impacts the sound in the room. Different subs built with different Q's are going to emphasize different frequencies and at different dB levels. If a sub is used that naturally has higher dB levels at the same frequencies that cause bad resonances in a room, then that would sound different than using a sub that has a naturally lower frequency response in the area of the room's bad resonance (similar to using an outboard eq?).
Sure, that single sweet-spot seat and speaker could be moved around for optimal sound quality (if you are a bachelor). But can a sub that naturally works against a room always be able to be made to sound the same as a sub that works with the room?


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> That Toole reference does support the notion that group delays can be adjusted with eq.
> 
> But to me, this also emphasizes the notion that the sound of the sub itself impacts the sound in the room. Different subs built with different Q's are going to emphasize different frequencies and at different dB levels.


Of course! That's why people use the type of sub as a "tone control" to align with their preferred taste or genre, music/movies. Until sophisticated EQ was available, that was the nature of the game. Now we have other options.



> If a sub is used that naturally has higher dB levels at the same frequencies that cause bad resonances in a room, then that would sound different than using a sub that has a naturally lower frequency response in the area of the room's bad resonance (similar to using an outboard eq?).


Yes.



> Sure, that single sweet-spot seat and speaker could be moved around for optimal sound quality (if you are a bachelor). But can a sub that naturally works against a room always be able to be made to sound the same as a sub that works with the room?


If the two subs in this hypothetical have no other disparate properties, and are of virtually identical physical construction, differing only in Q, they can be made to work identically with properly applied EQ. Sorry if this sounds very cagey. The original issue was about Q alone, so I am restricting the variables to Q.


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> Sorry if this sounds very cagey. The original issue was about Q alone, so I am restricting the variables to Q.


Not cagey.


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## chashint (Jan 12, 2011)

Before I added a sub to my system I was very concerned that I would know there was a subwoofer there all of the time, but the transition between the speakers and the sub is seamless and the difference I hear/feel is simply lower frequency content.
I would describe the sub as adding a presense to the sound, and this is a positive.
I have Klipsch RF83 speakers and Outlaw LFM1-EX subwoofer, in the AVR all the speakers are set to small and the crossover is set to 80Hz.
I have graphed the frequency response of the system with and without the sub, the sub does not add volume it extends the frequency range.
I have not noticed excessive sound (content) in the .1 channel (mix).


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## gdstupak (Jul 13, 2010)

There's much more than just a feeling of presence from my subs. There is discernible sound to content below 80hz, it's just not localizable (I think I just made up a new word?).
I listen to allot of jazz with upright bass, allot of classical music with bass drums and organ music. Organ music especially has allot of discernible bass. Those lower octave pedal notes have distinct sounds, each organ and venue sound different and a good sub should be able to relay those differences.

You're right, a sub should just be an extension of the frequency range.
I am not saying that I'm finding excess sound (as in volume) in the .1 channel, I'm saying that I'm finding instruments recorded into the .1 channel that I would rather have in the main channels. And then if that instrument plays content that is too low for my main speakers, then the AVR would direct those lower frequencies to the sub.


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## chashint (Jan 12, 2011)

You are pretty dead set that no one understands what you are saying but I assure you that is not the case as far as it pertains to me.

To your main point of the thread... 
*5.1 audio mixing (why so much .1)? I'm finding instruments recorded into the .1 channel that I would rather have in the main channels*

While I have no issue with you having this opinion, I simply disagree with you.

The one thing I cannot understand is if you are looking for help on how to address the problem of your sub woofers not sounding right.


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## gdstupak (Jul 13, 2010)

gdstupak said:


> There is discernible sound to content below 80hz,...
> I listen to allot of jazz with upright bass, allot of classical music with bass drums and organ music. Organ music especially has allot of discernible bass. Those lower octave pedal notes have distinct sounds, each organ and venue sound different and a good sub should be able to relay those differences..


This was just a general comment about sound below 80hz.
I didn't go into anymore detail since this was hashed over earlier. But in my system there is slightly more detail in those lower octaves when they are played through my main tower speakers. Both of my outboard subs have slightly less detail.
Both the subs and the main speakers are EQ'd the same in those lower octaves, between 30hz up to 100hz.
I was just making a general comment about my experience, not really asking questions, I guess if I had questions I would have asked one.
There's not much more I can do to change the sound of the outboard subs that I have now. They are in the only places that they will fit into my living room, and as mentioned earlier they are EQ'd to match my mains.
Right now I am in the process of building an IB sub into my living room ceiling. We'll see how that sounds pretty soon I hope.



gdstupak said:


> I am not saying that I'm finding excess sound (as in volume) in the .1 channel, I'm saying that I'm finding instruments recorded into the .1 channel...


If you are saying that you have not heard this, I wouldn't be surprised. So far it isn't a common practice that I've heard. And it was sometime last year that I went through a period of renting 5.1 music dvd's/bluray's so off the top of my head I can't recall specific recordings that did this.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> Both the subs and the main speakers are EQ'd the same in those lower octaves, between 30hz up to 100hz.


How did you verify this?


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## gdstupak (Jul 13, 2010)

Roger Dressler said:


> How did you verify this?


SPL meter with test tones. All SPL measurements were taken from the same location, the main listening seat.
As I mentioned earlier, when I mention EQ or frequency response I'm speakeing of simple SPL measurements at frequencies played with a test disc. 
Both my subs and main speakers match SPL levels at the frequencies played by the test disc.


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## gdstupak (Jul 13, 2010)

About frequency response and how a sub sounds (once again, referring to simple measurements of frequency SPL): 
_"Contrary to Consumers Union's claims, speakers that appear to measure alike in the frequency domain may differ significantly in sound quality—even at drive levels that produce negligible distortion products."_

The entire article is here: http://www.stereophile.com/features/189subs/index.html

This article (and I believe Toole also) mentions a more accurate representation of how a sub will sound is measuring sound in the time domain, such as with waterfall graphs.

I wish I had REW running to measure this, but not yet.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> SPL meter with test tones. All SPL measurements were taken from the same location, the main listening seat.
> As I mentioned earlier, when I mention EQ or frequency response I'm speakeing of simple SPL measurements at frequencies played with a test disc.
> Both my subs and main speakers match SPL levels at the frequencies played by the test disc.


Then it is safe to say that there is every likelihood that the frequency responses do not match well after all, and therein lies the reason the bass sounds different.


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## gdstupak (Jul 13, 2010)

If the SPL measurements are the same, then the freq responses probably don't match?
I'm lost.


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> About frequency response and how a sub sounds (once again, referring to simple measurements of frequency SPL):
> _"Contrary to Consumers Union's claims, speakers that appear to measure alike in the frequency domain may differ significantly in sound quality—even at drive levels that produce negligible distortion products."_


Yes, one must be very careful in interpreting response measurements.



> The entire article is here: http://www.stereophile.com/features/189subs/index.html


It's a good article. The referenced AES paper by Gannon and Benjamin is also quite good, but the part about "don't put the sub in the corner" is a bit out of date now since Welti showed how to take advantage of corners with multiple subs. (Mr. Benjamin is also an old friend of mine--we worked together at Dolby.) 



> This article (and I believe Toole also) mentions a more accurate representation of how a sub will sound is measuring sound in the time domain, such as with waterfall graphs.


Yes, there are much more sophisticated ways to measure the total performance of rooms/speakers. 



> I wish I had REW running to measure this, but not yet.


It will be fun!


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## Roger Dressler (Aug 1, 2009)

gdstupak said:


> If the SPL measurements are the same, then the freq responses probably don't match?
> I'm lost.


When you get REW running, you will see that they do not actually match at all the frequencies.


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