# Target Curve - New Discovery



## Spridle

OK guys, since I have been an REW user for almost a year and have experimented quite a bit, I thought I should make this post.

I have always been confused as to what the ideal target curve should look like, but I have found an answer that works extremely well—at least in my case.

I recently received a room correction software upgrade to my sound processor. It's something like a built-in digital parametric EQ that works across the entire frequency spectrum—an REW of sorts. It shipped with a calibrated microphone. Unlike REW, it does not give the user much control over what it does, but I have to say that the results are amazing. I am experiencing the best sound ever. I really have no more complaints about my system and my tweaking days are over.

Similar to Wayne’s "house curve", one of the philosophies behind this room correction is the concept of "room gain" in the low end, which every room has and recording engineers expect when they mix. Also, it corrects for speaker performance and room interactions and creates a flat curve in the mids and highs which make a huge difference in vocals, guitars, cymbals, imaging, soundstage, sparkle, etc.

What I thought would be helpful to REW users is showing you the curve I get when I measure my corrected system with REW using a calibrated microphone. In my attached REW graph (avg. of 5 positions), note the room gain in the low end, the flatness in the mids, and the roll-off in the highs. One thing that was a little different is the software determined a crossover of 120Hz for my subs/mains, instead of 80Hz. But, if you look at my uncorrected curves, 120Hz visually appears to be the most natural choice for the crossover frequency in my case. I tried 80Hz and others but ultimately 120 really was the best sounding. Your room will vary.

Here are the values for my blue target curve in case you want to experiment. The size of the hump apparently varies with room size, so you may need to make the hump smaller or larger:

15 5
20 8
30 11
50 11
70 8
100 2.5
150 1
200 0
2000 0
8000 -1
10000 -2
13000 -4
16000 -10
20000 -20

Of course, you can use the BFD or a Velodyne SMS-1 on your subs. For your mains, tone controls or treatments may do the trick. If you want to take it to the next level, I have previously used Rane PE-17 parametric EQs (bought on EBay) for my mains with no audibly detectable coloration, noise or distortion added. This is a good way to go. I even found a way to precisely set the filters on the Ranes using REW. See a prior post of mine for the technique.

Also attached are the graphs from my processor software that shows my curves before correction (red) and after correction (green).

Hope this info is helpful.


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## Wayne A. Pflughaupt

Interesting post, Spridle!

So the blue line is what the processor generated?



> Also, it corrects for speaker performance and room interactions and creates a flat curve in the mids and highs which make a huge difference in vocals, guitars, cymbals, imaging, soundstage, sparkle, etc.


Something to listen for, the fundamentals of mid to upper-mid bass notes reside in the 100-300 Hz range, so this curve might leave them sounding reduced in level. Of course, that’ll be of little consequence for home theater.



> If you want to take it to the next level, I have previously used Rane PE-17 parametric EQs (bought on EBay) for my mains with no audibly detectable coloration, noise or distortion added. This is a good way to go. I even found a way to precisely set the filters on the Ranes using REW. See a prior post of mine for the technique.


I’ve regularly been sending people to that thread when they inquire about the benefits full-range equalizing. :T

Regards,
Wayne


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## Spridle

Wayne A. Pflughaupt said:


> So the blue line is what the processor generated?


On the REW graph, the blue line is the target curve I created with points to generally follow the red response line that I measured with REW. The red response line was from measurements taken after the processor does its thing and is an average of 5 positions. When I measured with REW then looked at the graphs, I was surprised to see the size of the hump and the narrow range it covers compared to the house curve I was using before which was basically a 4db boost house curve. I was also surprised that the bass does not sound "louder" than before, but rather tighter and more precise. On the graph, the gain at 30-50Hz is a whopping 11dB.



Wayne A. Pflughaupt said:


> Something to listen for, the fundamentals of mid to upper-mid bass notes reside in the 100-300 Hz range, so this curve might leave them sounding reduced in level. Of course, that’ll be of little consequence for home theater.


I primarily listen to music, so accuracy and realism are most important to me. The sound is very balanced across the spectrum and sounds very much like live music, especially when cranked up. The bass is tight, punchy, and smooth -- much more so than before. The Basia bass line is particularly impressive. Believe it or not, I have been tweak-free for about 2 weeks and haven't heard anything that has caused me to get up and try a new setting.



Wayne A. Pflughaupt said:


> I’ve regularly been sending people to that thread when they inquire about the benefits full-range equalizing.


It would be interesting to hear about the results with the Ranes and what target curves are used. I'll search the thread to see if anything has been posted.


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## Wayne A. Pflughaupt

> On the REW graph, the blue line is the target curve I created with points to generally follow the red response line that I measured with REW. The red response line was from measurements taken after the processor does its thing and is an average of 5 positions.


Ah. Well then, I can't help but notice that the red-line response the processor generated has the house curve shelving at ~30 Hz, a figure I mentioned in my house curve article. 

Are you still using the Ranes, or did the processor have EQ to replace them?

Regards,
Wayne


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## Spridle

I have removed the Ranes. I have the processor room correction set to work up to 15K Hz.


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## tnargs

This looks like the RoomPerfect curve. I am using a similar (slightly different) target for my DEQ2496. 

The RoomPerfect people claim that it is based on the principle that we are used to hearing room gain when we are in a room. I think this is a weak rationale.

However, much more important to me, is that most final mastering of recordings is done in a studio, which will have room gain. The mastering EQ is therefore based on sounding right in a room with room gain. In these (dare I say normal) cases, it would result in too little bass in our rooms if we EQ flat in the bass.

You would be making a mistake to say your search for a target curve is over. Some recordings are mastered with headphones (shudder). And some are so-called 'direct to disc', which can mean what it says, but more generically means recordings that are effectively unmastered, e.g. some of the Water Lily Acoustics recordings of live classical work captured direct to two microphones and not further equalised, or recordings like Marcus Miller's _Ozell Tapes_ that are mastered direct from the mixing desk. Such 'unmastered' recordings will sound too bass heavy (I can vouch for it) because your target curve needs to be flat in the bass for them.

So you need to have a few target curves on hand. But the one you are using is a better default setting than flat (eech) or X-curve (misapplied in the home living room), which I have used over the years.


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## thewire

tnargs said:


> This looks like the RoomPerfect curve. I am using a similar (slightly different) target for my DEQ2496.
> 
> The RoomPerfect people claim that it is based on the principle that we are used to hearing room gain when we are in a room. I think this is a weak rationale.
> 
> However, much more important to me, is that most final mastering of recordings is done in a studio, which will have room gain. The mastering EQ is therefore based on sounding right in a room with room gain. In these (dare I say normal) cases, it would result in too little bass in our rooms if we EQ flat in the bass.
> 
> You would be making a mistake to say your search for a target curve is over. Some recordings are mastered with headphones (shudder). And some are so-called 'direct to disc', which can mean what it says, but more generically means recordings that are effectively unmastered, e.g. some of the Water Lily Acoustics recordings of live classical work captured direct to two microphones and not further equalised, or recordings like Marcus Miller's _Ozell Tapes_ that are mastered direct from the mixing desk. Such 'unmastered' recordings will sound too bass heavy (I can vouch for it) because your target curve needs to be flat in the bass for them.
> 
> So you need to have a few target curves on hand. But the one you are using is a better default setting than flat (eech) or X-curve (misapplied in the home living room), which I have used over the years.


I think that most mixing studios are checked out by Dolby Digital and they mix the master using an X-Curve. When they go back an recode for the format DVD, Blu-Ray, Digital Copy :scratchhead:, they are mixing for an enviornment that is entended to be flat, unless they expect you to do the curve yourself. How to know which is right can be impossible. I wish that I knew a way of extracting these metatags or downloading them that are intended for the THX Media Director. Better yet they should just make it all public so we can know how the mixes were done. That is probobly asking too much but it would be nice. Even then we would have to rely on the people releasing the media to tell us, and they already don't as it is most of the time.


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## tnargs

I agree it would be sooo pleasing if people in the industry (the big players) would join the internet discussions and make interested audiophiles aware of the room acoustic they would recommend for the recordings. Then we could aim for that. At the moment it feels like groping in the dark!


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## tnargs

thewire said:


> I think that most mixing studios are checked out by Dolby Digital and they mix the master using an X-Curve....


If so, they would be doing the consumers no favour. 

In the bass, it means anyone with room gain will hear excess bass. Since every room has room gain, only the very few consumers with equalised flat bass will hear bass at the right level. OTOH it is good news for those of us who do equalise.

In the treble, an average-sized listening room has no X-curve, i.e the pink noise treble does not fall off in the treble. So, again, no one will hear the treble at the right level at home.

OTOH if it is true, we home EQ guys have something to work with.... :neener:


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## Wayne A. Pflughaupt

From Part Three of my house curve article:

_As industry pro Tomlinson Holman explains in this article, the X curve is used in both theaters and dubbing soundstages. He readily acknowledges the problem most of us are aware of with home movie releases, that “when heard over a modern flat loudspeaker in a small room, program material balanced on an X curve monitor sounds overly bright.” Mr. Holman adds, “This is not too important because, so long as everyone [in the industry] agrees to use the same curve, then the response sounds the same to the mixer on the dubbing stage as to the audience member in any auditorium. Interchangeability of X curve material with home video can be handled with a simple re-equalization.”_



tnargs said:


> The RoomPerfect people claim that it is based on the principle that we are used to hearing room gain when we are in a room. I think this is a weak rationale.


Try taking your speakers outside and the first thing you’ll notice is the bass is gone.



> So you need to have a few target curves on hand. But the one you are using is a better default setting than flat (eech) or X-curve (misapplied in the home living room), which I have used over the years.


I’ve had satisfactory results merely adjusting the system for a house curve appropriate for the room, and then adjusting the overall sub level up or down as (occasionally) needed (which is easy since I have remote control for my subs).

Regards,
Wayne


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## tnargs

Wayne A. Pflughaupt said:


> From Part Three of my house curve article:
> 
> _As industry pro Tomlinson Holman explains in this article, the X curve is used in both theaters and dubbing soundstages. He readily acknowledges the problem most of us are aware of with home movie releases, that “when heard over a modern flat loudspeaker in a small room, program material balanced on an X curve monitor sounds overly bright.” Mr. Holman adds, “This is not too important because, so long as everyone [in the industry] agrees to use the same curve, then the response sounds the same to the mixer on the dubbing stage as to the audience member in any auditorium. Interchangeability of X curve material with home video can be handled with a simple re-equalization.”_


To which I responded here (over a year ago):
http://www.hometheatershack.com/for...ve-some-advice-its-use-non-use.html#post68712 



> Try taking your speakers outside and the first thing you’ll notice is the bass is gone.


Supporting my point that I disagree with the RoomPerfect people’s notion that we are “used to” hearing room gain in our homes (and by extension “used to” the lack of bass outdoors). If that were true, we would not notice the change indoors vs out.



> I’ve had satisfactory results merely adjusting the system for a house curve appropriate for the room, and then adjusting the overall sub level up or down as (occasionally) needed (which is easy since I have remote control for my subs).


I am interested in what you think is a house curve “appropriate to the room”. I may be wrong but I think for a home-sized listening room, the appropriate house curve is zero. The need for X-curve EQ gradually diminishes with room size from 100% for an auditorium or theatre, to zero for typical lounge or listening rooms. For example, there is a Small-Room X Curve, designed to be used in rooms with less than 150 cubic meters, or 5,300 cubic feet. This standard specifies flat response to 2 kHz, and then rolling off at a 1.5 dB/octave above 2 kHz.

Somewhere on the "Secrets of Home Theater and High Fidelity" there is an article on the topic which says:

_"Since the advent of Dolby Stereo though, the soundtrack of virtually every movie (be it Analog or Digital) is crafted for playback over a system equalized to the XCurve and set at the reference playback level. Unfortunately there is no entry in the X-Curve table for rooms as small as most home theaters, and even if there were, like theaters and studios, you'd need 1/3 octave equalization on each channel to conform. Don't worry. Read on.

"If you could get your hand on the X-Curve table, one corollary would stick out for you: As the rooms get smaller, less and less of a roll-off is defined, because as we said, smaller rooms have less of the reverb which the X-Curve addresses.

"By the time we shrink a room down to typical home theater size, we can say that no X-Curve compensation is needed, much to the contrary of popular opinion. There is not an inherent overabundance of treble in motion picture soundtracks, at least not due to the X-Curve."_​
Makes sense to me.


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## thewire

Your not taking into account how close one is to the speaker. The speaker will sound harsh at times depending on the mix unless it is factored into the remix and encoding proccess to disc. I hear it sometimes but other times it is not as bad. It is dependent on what the film maker wants to do mostly. If they are listening to speakers that are not going to sound harsh while they mix, it isn't going to sound that way. Here is a quote directly from the THX website about their version of Re-Eq.



> THX Re-EQ is a compensation technology taking soundtracks that are mixed for large cinemas, where speakers are placed farther away from you, and re-establishes the accurate tonal balance for your *close range home theater speakers*. Without THX Re-EQ, higher frequencies sound excessively “edgy” or “bright.” With THX Re-EQ, the movie soundtrack is true to the original immersive cinematic experience.
> 
> Example: The THX Certified DVD classic action film Aliens is loaded with audio and visual effects. When watching this film with THX Re-EQ activated in your THX Certified receiver or pre-amplifier, the technology adjusts and reproduces the high frequencies to play at the appropriate audio level in your home. Otherwise these frequencies would sound overbearing and distracting.


My pre/pro calls this theater mode.


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## tnargs

thewire said:


> Your not taking into account how close one is to the speaker.


Sure I am (or did, in Dec 07):
http://www.hometheatershack.com/for...ve-some-advice-its-use-non-use.html#post68712



> The speaker will sound harsh at times depending on the mix unless it is factored into the remix and encoding proccess to disc. I hear it sometimes but other times it is not as bad. It is dependent on what the film maker wants to do mostly. If they are listening to speakers that are not going to sound harsh while they mix, it isn't going to sound that way.


No argument.

I still reckon the X-curve for a small (home) room is zero.:hide:

In saying the X-curve is zero, I am not saying there is no need for EQ in the home. I am only saying that the reasons EQ is needed are not founded in the X-curve rationale. Therefore the shape of EQ that is needed in the home is not based on the X-curve's shape.


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## Wayne A. Pflughaupt

tnargs said:


> Wayne A. Pflughaupt said:
> 
> 
> 
> From Part Three of my house curve article:
> 
> _As industry pro Tomlinson Holman explains in this article, the X curve is used in both theaters and dubbing soundstages. He readily acknowledges the problem most of us are aware of with home movie releases, that “when heard over a modern flat loudspeaker in a small room, program material balanced on an X curve monitor sounds overly bright.” Mr. Holman adds, “This is not too important because, so long as everyone [in the industry] agrees to use the same curve, then the response sounds the same to the mixer on the dubbing stage as to the audience member in any auditorium. Interchangeability of X curve material with home video can be handled with a simple re-equalization.”_
> 
> 
> 
> To which I responded here (over a year ago):
> http://www.hometheatershack.com/for...ve-some-advice-its-use-non-use.html#post68712
Click to expand...

Hmm... not sure how that one got past me, but IIR, I was working long hours at the time.

Wow – where to begin?

The point of the quote I italicized in my previous post was to show that the movie industry utilizes the X curve for both production (soundstages) and playback (movie theaters), which was in keeping with the discussion (please review the posts above it). And no, that was not something you addressed or even mentioned in your Dec. 2007 thread.

Reviewing both your 2007 thread and your comments above in Post #11, it looks like you’ve been confusing a house curve with the X curve:


> I may be wrong but I think for a home-sized listening room, the appropriate* house curve* is zero. The need for *X-curve* EQ gradually diminishes with room size from...





> I also cannot leave be the stated notion that the *house curve* is one where the listener hears all notes or tones at the same loudness…
> 
> My conclusions? Yes, most recordings sound too sharp with flat EQ’d pink noise at the listener’s seat. No, it is not due to the *X curve* effect...


The X curve is _specific to the film industry_ (not pro audio as you surmised – that’s PA systems used in all sorts of public venues). It’s something they came up decades ago to address the deficiencies in optical soundtracks and old-school speakers.

Best as I can tell by wading through the article I linked above and Dolby Lab’s History of the X Curve, Ioan Allen of Dolby Labs and other movie industry types came up with the X curve back in the early 70s by comparing hi-fi KEF speakers located near-field with old-school film monitors located far-field, equalizing the latter until they felt they timbre-matched the former (which strikes me as a futile exercise going in). After this exercise the film monitors' “new” response was electroacoustically measured. All parties in attendance where surprised to find that the film monitors exhibited not the KEF’s verified flat response, but a roll out of the high frequencies above 2 kHz. They couldn’t readily explain the discrepancy, but nevertheless the curve they’d measured was later adapted as the X curve. Never mind that the ancient film monitors were dead in the water above ~8kHz to begin with, or perhaps their prehistoric compression drivers just sounded nasty with their highs suitably elevated so maybe they instinctively kept them rolled back. Or maybe their primitive equalizers were doing the film monitor no favors. Who knows? They sure didn't, and they made no attempt to get to the bottom of it.







​

Subsequent testing took reverberation in movie theaters into account and further validated the X curve as suitable for maximizing _speech intelligibility_ in movie soundtracks. The curve’s low-end roll off was implemented to minimize distortion from overloading the speakers of the day.

Over the decades as advancements in professional loudspeaker design have improved both low- and high-end extension, the film industry has rigidly adhered to the X curve, essentially keeping movie theater sound “dumbed down” to the level of the inferior stuff that was used “back in the day.” Adding insult to injury, modern theaters are much more- and better-dampened than they were in the past, diminishing the effect of reverberation on both measured response and speech intelligibility; yet the X curve remains.

Small wonder that movie theaters today sound dull and lifeless, and small wonder that an X curve didn’t sound good in your home theater. Bottom line, whoever told you it was the gold standard for a domestic audio system should be severely beaten. :yes:

If you review the house curve article, you’ll find that I never claimed that the X curve was intended for use in a home theater, or any domestic system. Indeed, I thoroughly refuted the notion of applying _any_ kind of rigid-value slope (which is what the X curve is) that purported to be the reference standard for any and every room (which again, is what the X curve is). As such, I fully agree with the quotation you presented from _Secrets of Home Theater and High Fidelity,_ as well as your own personal conclusions: The X curve was never intended for our tiny rooms and should not be used. :T

Likewise, I never claimed that dialing in a proper house curve (which is not the same thing as an X curve) would result in every recording magically sounding perfect. That’s an impossible goal. The whole point of the article was to show that a house curve is needed in order for a system to sound natural and balanced. I offered a few tips on how to accomplish that goal. This is what audio professionals call “calibrating” or “setting up” a system. It is accomplished with various response-measuring tools, and confirmed afterwards with program material that the calibrator has found to be a good representation of an accurate recording, making further adjustments at that point as needed, irrespective of what the measurements may indicate. It should be noted that global calibration of the system _is not the same thing as compensating for deficient program material._

However, in the world of home theater, rife with untrained, amateur system “calibrators,” the house curve will naturally reflect the owner’s personal tastes and expectations. For instance, we can anticipate that a basshead fresh from the world of car audio, or someone who’s used to the “boom-sizzle” generated by a smiley-face EQ curve, will expect that their home theater should sound the same.

That’s not really a problem. Once the system is calibrated, even if it’s intentionally “miscalibrated” to accommodate the owner’s taste and expectations, it becomes their personal point of reference. The notion of calling up a different house curve for every DVD or CD that’s loaded up – or as I’d characterize it, deliberately un-calibrating the system - is not the proper way to do things.

Basically, IMO you’re making all of this much more difficult than it should be. Just calibrate the system to sound as accurate as possible in your room and call it a day. At that point, whatever you put in your DVD or CD player - “it is what it is.” If a certain CD or DVD has, for example, bloated midbass – fine, I assume that’s the way the director or producer wanted it to sound, right or wrong. I’m not interested in re-equalizing my whole system to “unbloat” their idea of “correct.” As I noted, addressing problems in program material is a whole ‘nother cantaloupe from proper system calibration, and should be only general, not wholesale, temporary adjustments. As such, the most I will do is a broad, overall adjustment to the treble or (bloated-sounding) bass if it is excessive or deficient. If you find yourself making the same adjustments on a regular basis – e.g. always dialing the treble up a few notches – then tweaking the system a bit further is in order.

Regards,
Wayne


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## thewire

tnargs said:


> Sure I am (or did, in Dec 07):
> http://www.hometheatershack.com/for...ve-some-advice-its-use-non-use.html#post68712
> 
> 
> 
> No argument.
> 
> I still reckon the X-curve for a small (home) room is zero.:hide:
> 
> In saying the X-curve is zero, I am not saying there is no need for EQ in the home. I am only saying that the reasons EQ is needed are not founded in the X-curve rationale. Therefore the shape of EQ that is needed in the home is not based on the X-curve's shape.


It's going to not resemble an X-Curve in a home if the mix was not redone for home. It is going to exagerate bass, not be flat. The purpose of Re-Eq is to make it flat, *not* like an X-Curve, because the mix was not remixed for a home theater.

A mix itself has zero X-curve most of the time because it has been remixed for home but it is not related in any way to a home theater enviornment. What you have instead is a mix where it sounds correct to a mixing room enviornment. If the room is overly dampened your going to hear bass that is muffled, distorted, perhaps even way too loud. It has been tried to match mixing studios to sound the same, but it has failed to have worked. The idea of mixing with an X-Curve, then correcting that is to take the sound in the cenema, and bring that to the home enviornment so you hear how the mix was intended originally instead of hearing what someone thought it sounded right in the mix room. Why you would be against ones choice of using Re-Eq to correct for a theater X-Curve whether left intinitally or not, I am not clear on. It sounds like you would prefer to listen to the way it would be mixed for the theater in a home enviorment. :dontknow: 

As Wayne explained, an X-Curve and a shelving filter are not related. The purpose of one is using the same standard for older theaters, and the purpose of the other is what a person prefers.


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## JimP

Wayne A. Pflughaupt said:


> ...snip...
> 
> Basically, IMO you’re making all of this much more difficult than it should be. Just calibrate the system to sound as accurate as possible in your room and call it a day. At that point, whatever you put in your DVD or CD player - “it is what it is.” If a certain CD or DVD has, for example, bloated midbass – fine, I assume that’s the way the director or producer wanted it do sound, right or wrong. I’m not interested in re-equalizing my whole system to “unbloat” their idea of “correct.” As I noted, addressing problems in program material is a whole ‘nother cantaloupe from proper system calibration, and should be only general, not wholesale, temporary adjustments. As such, the most I will do is a broad, overall adjustment to the treble or (bloated-sounding) bass if it is excessive or deficient. If you find yourself making the same adjustments on a regular basis – e.g. always dialing the treble up a few notches – then tweaking the system a bit further is in order.
> 
> Regards,
> Wayne


Wayne,

I agree with what you say but only up to a point. Consider that TNT and certain shows on SciFi have something major wrong with their bass, I don't think you have much a choice but to have a different setting (or memory) in your Sub EQ setup. Coming up with a compromise setting that you can use for everything is most likely to result in settings that don't sound good for anything. I'm not sure exactly what TNT is doing, but for the time being I'm just lowering my Sub EQ by 6dbs. There may be more adjustments needed, but this at least gets it into the ball park.


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## thewire

JimP said:


> Wayne,
> 
> I agree with what you say but only up to a point. Consider that TNT and certain shows on SciFi have something major wrong with their bass, I don't think you have much a choice but to have a different setting (or memory) in your Sub EQ setup. Coming up with a compromise setting that you can use for everything is most likely to result in settings that don't sound good for anything. I'm not sure exactly what TNT is doing, but for the time being I'm just lowering my Sub EQ by 6dbs. There may be more adjustments needed, but this at least gets it into the ball park.


A format your watching on your DVD or Blu-Ray is broadcast. This is a different type of mix. It is done with the intential expectations that the mix is compressed, and adjustments are done according to what it supposed to sound like however... The equipment that is envolved in the playback of these broadcast will vary and a service provider is not going to use the same compression from one to the next. What you have instead is a problem where someone has not checked the quality of the boadcast, or they did a poor job at it. It is much more simple to simply turn down the level. Dialing in a curve isn't going to correct something like this, as it will also not specifically address tonal balance or impact in a specific recording on Blu-Ray or DVD, which is going to be alot more consistant from one player to the next. Contrary to common beleif, we are not all watching the same episode on local channels as well. What is on air is up to your local broadcast provider. Thought I might mention that also..


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## thewire

I'm sorry. I confussed a statement I made earlier in this thread. Most movies that are mixed for the cemema will benifit with RE-EQ. The majority of material we may be expossed to however such as games or broadcast will not benifit from RE-EQ.


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## wackii

I've stumbled to this thread the other day and decided to give this target curve a try. I've recently bought a Marantz SR8001 and real happy on the SQ. Anyway, this receiver has the MultEQ Audyssey calibration built in. I was trying to tweak the manually calibration to my best to get it closer to this target curve. I'm really like how it sounds especially on the vocals, but it seems to lack on the bass department though. I like how the Audyssey setting sounds more with the bass. So I combined this target curve with the lower freqs Audyssey target curve and got what I want. It sounds great with music and movie now. I really like how it sounds now, even GF give a thumb up on the newer EQ system.

Here is my curve.

15 15
20 15
30 15
50 11
70 7.5
100 2.5
150 1
200 0
2000 0
8000 -1
10000 -2
13000 -4
16000 -10
20000 -20

My measurements with Target Curve









Before and After graph.
Green = Audyssey OFF; Yellow = Audyssey ON; Blue = EQ FLAT; Red = Preset - manual calibration (volume was 1 db higher by accident)









Thanks Spridle and everyone else for the target curve.

Al,


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## Siamize

hi wackii and all

I'm just new to the thread but I thought that you all might find this interesting and particularly wackii as the "Real X Curve" described in this linked document pretty much matched your target curve.

(Seeing I haven't done five posts you'll have to do the link yourselves)
siamize.vpscustomer.com/sound/the_mythical_x_curve.pdf



It also puts simply what a lot of the main points of what has been said in the thread which I've summaries below

1. Large/small rooms need a different house curves .... it gives some recommendations which I think are pretty much in keeping with comments/recommendations previously posted.

2. How the "official" X curve is some what dated and was based on how things sounded on old equipment (not that I was around back then) but how now with newer systems extreme frequencies are reproducable (ie. below 100 Hz & above 8k) and hence it suggests the "Real X Curve".

3. The cabin effect with the possible modification of the "Real X Curve" for boomy rooms along with Point 1 recommendations.


My take on a house curve is that it is a standard so that when you take your CD/DVD from one house/room to the next it will sound the same. The electronics (including speakers), room shape, occupants & furnishings are all part of the "house".


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## Siamize

Tested out the Real X Curve in the previous posts document 
(ie. the_mythical_x_curve.pdf) in a 200 seat auditorium ... way to much highs is my only comment . It might have sounded OK in a small home theater but not a room 15mx26m with a 4.8m ceiling. I modified it a bit. Kept the same under 2kHz but then used the standard X Curve over 2k with the recommendationed modifications for a 200 seat auditorium as the std X Curve is for a 500 seat room. Hence, the House Curve was as below although I shelved the really low sub bass. I was very happy with how music sounded through the system.


20	6
80	6
100	2
110	0
2000	0
10000	-6.0
20000	-11.5


On a side note, I was a bit confused how after I EQed the house for the "Real X Curve" yesterday and then came back today to apply move the roll off at the top from 8k to 2k, I first check to see if if the EQ was still OK from yesterday and it wasn't even though all the setting were the same. The house wasn't responding the same way and needed reEQing even though all the EQ setting were exactly the same. I know that because I wrote them down just to make sure no little fingers had changed them during the day or at anytime in the future.


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## Wayne A. Pflughaupt

> On a side note, I was a bit confused how after I EQed the house for the "Real X Curve" yesterday and then came back today... The house wasn't responding the same way...


Not at all unusual. While the measurement platform is stable enough (REW for example), the transducers involved - the speakers and elements in the microphones - are not. Their physical (and consequently electrical) properties are altered with changes in temperature, humidity, etc. This is why response readings taken at one session may not “look” the same as those taken at a later date.




> I know that because I wrote them down just to make sure no little fingers had changed them during the day or at anytime in the future.


You might want to get a security cover for the equalizer...

Regards,
Wayne


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## Siamize

Well suprise suprise. When I checked the house response today after setting it up to my modified Real-X-Curve, the house response was different. Yesterday I was cooler and much more humid (rained on and off from about 3am through to 2pmish on and off) whereas today was relatively warmer and clear skies.


Anyway how much different ... see the picture at ...
siamize.vpscustomer.com/Sound/100414%20-%20PCCC%20eq.jpg

The blue line is the target house curve. This has been subtracted off the true response of the GREEN (yesterday's response after EQing) and the YELLOW (today's response without changing yesterday's EQing) so that the response shown should looks flat. This makes it easier when EQing to know how much to cut/boost especially when your target house curve is sloping and varied.

I thought I'd post it just to show how much variation can happen from one day to the next even when the setting on the electronics are all the same.


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## Siamize

Wayne A. Pflughaupt said:


> You might want to get a security cover for the equalizer...


Yea have thought of that but it's a digital one and I've stored the settings to the presets. It's more so that I'm not the only operator of the system.


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## Wayne A. Pflughaupt

> It's more so that I'm not the only operator of the system.


Matters not, the equalizer should be “set and forget.” The various “operators” shouldn’t be messing with it.




> I thought I'd post it just to show how much variation can happen from one day to the next even when the setting on the electronics are all the same.


I must say, a “new day, new reading” deviation of -4 / +8 dB is pretty shocking.

Is the green line actual measured response, after equalization?

Regards,
Wayne


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## Siamize

Wayne A. Pflughaupt said:


> Matters not, the equalizer should be “set and forget.” The various “operators” shouldn’t be messing with it.


Yes I know but you know sound engineers ... always want to tweak things a little.




Wayne A. Pflughaupt said:


> I must say, a “new day, new reading” deviation of -4 / +8 dB is pretty shocking.


I was very suprised myself. That's what why I posted the reponses to see if others had tested their systems with the same setting on different days. I'll test it again today too as the weather is not as extreme as such ... today looks like it'll be clear skies and much the same temp as yesterday.



Wayne A. Pflughaupt said:


> Is the green line actual measured response, after equalization?


Yes but with the inverse of the target curve applied. That way you are chasing a "flat response" on the screen. The sub has a separate volume control, the crossover is about 110Hz, and the sub only has a 4 band parametric EQ. Whereas the main front of house has the 4band parametric EQ + 32band EQ. I would have liked to have got that lower area (40-160Hz) a little flatter but I run out of time / was running really late for my next appointment by that time.

Also I've been EQing to a 20Hz to 20kHz to 20Hz logrithmic frequency sweep/cycle. The sweep duration from 20Hz to 20kHz is 20secs. I find this much more replicable than using pink noise - also a bit easier to listen too.


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## Wayne A. Pflughaupt

Siamize said:


> Yes but with the inverse of the target curve applied.


So it's not an actual in-room response reading? It's a response reading plus some kind of tweak in the software?

Regards,
Wayne


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## Siamize

Well it seems that the atmospheric conditions may play a larger role than most expect. Today the house reponse was much the same as yesterday's response with the same EQ settings unlike the day before when it was much more humid and a little cooler.

http://siamize.vpscustomer.com/Sound/100415 - PCCC eq.jpg


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## Siamize

Wayne A. Pflughaupt said:


> So it's not an actual in-room response reading? It's a response reading plus some kind of tweak in the software?


 Correct. As you can see in my last post (ie. "100415....jpg") I've shown what is looks like with the inverse House Curve (the blue target curve on "100414....jpg) added to the actual response. Thus the actual reponse is the ORANGE curve but with you get the program to apply in the inverse of the House Curve you get the light blue curve.

For example: As the House curve is +6dB from 20-80Hz, when you apply the inverse it added -6dB to the actual responses from 20-80Hz. As the house curve is +0dB from 125-2000HZ, when you apply the inverse it added -0dB to the actual responses from 125-2000Hz. Then is does similar where the house curve is sloped. Thus when your setting your EQ, your target will be level which is easier to workout how many dB to boost/cut and at what frequencies. I found though that sometimes a 1dB boost on the EQ can lead to more/less than 1dB boost in the room response due to absorbtion and reverberation etc. But it gives you a much clear guide as to where to cut/boost than without applying House Curve. Is that clear?


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## Wayne A. Pflughaupt

Not really. I guess it has something to do with TrueRTA, which I've never used and know nothing about. Every RTA I've ever used, you just EQ'd to get response to match the Target curve (which included a house curve), such as you see in the graph below (which I lifted from Post # 1 of this thread). So the graph you get is an actual response reading. I wouldn't find any other kind particularly useful.










*Blue Trace - Target
Red Trace - Measured Response w/ EQ*​

Regards,
Wayne


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## Siamize

Wayne A. Pflughaupt said:


> Not really. I guess it has something to do with TrueRTA, which I've never used and know nothing about. Every RTA I've ever used, you just EQ'd to get response to match the Target curve (which included a house curve) ...... I wouldn't find any other kind particularly useful.


Yea I guess I thought that way when I first saw the feature. It's not really a feature for determining what your house response is but rather a tool to help when shaping the house response to a target (particularly EQing). I've played around with quite a few RTA's and never come across it before either. However, now that I have it, I find it quite useful when shaping the house response. 

I guess that it's only over the last 2 weeks that I've researched an objective way of EQing to a standard rather than just what sound's good. The digital 32 Band eq that we use has an autoeq (ie. it play's pink noise and set up the eq to a target but there was no guidance as to what that target should be and as we all know flat doesn't normally sound good - particularly in large rooms) so I was really looking for somekind of standard. That's how I've ended up here. Now I think I've found that standard this tool help apply that standard easily.

Giving a little more history ... I've done some recording over the last 6 months with my new Zoom R16 and have had trouble mixing the recordings so that they sound similar in various sound environments - particulary setting the bass level with respect to the rest of the mix. So this has all kind of resulted from that and live mixing.


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## Siamize

Well after a bit of research on how temperature, air pressure & relative humidity affects sound I put together this spreadsheet.

http://siamize.vpscustomer.com/Sound/Atmospheric Sound Attenuation.xls

It seems that only frequencies over 2kHz are significantly affected. As my main differences were in the 500-1000Hz range I think that difference may also be to do with the fact that the natural frequency of the room (ie one with the highest R60 value) is about 600Hz. 

As my measurements were taken at exactly the same place, modal interference/construction changes can be very significant from reflected signals with even the slightest atmospheric changes. See http://www.rane.com/pdf/ranenotes/Enviromental Effects on the Speed of Sound.pdf 

So my next readings with be from a variety of locations in the room as obviously in my room (15x26x4.5m) frequencies of this range are reverberated quite a bit and thus interference factor can really mess with EQing with even a slight change in atmospheric conditions.


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## Wayne A. Pflughaupt

> It seems that only frequencies over 2kHz are significantly affected. As my main differences were in the 500-1000Hz range I think that difference may also be to do with the fact that the natural frequency of the room (ie one with the highest R60 value) is about 600Hz.


Don't forget that changes in temperature and humidity will have an effect on the transducers involved - i.e., the speakers and measurement mics. Expansion and contraction and all that. That will potentially have some effect on measurements across the entire frequency spectrum, even if it's not enough to be audible.

Regards,
Wayne


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## Siamize

Wayne A. Pflughaupt said:


> effect on the transducers involved - i.e., the speakers and measurement mics.


Yes, most definately. I did think of that but just forgot as I was writing the last post. I think that the temperature & humidity would have an effect quite and effect on the stiffness of the membranes of the transducers and thus change their response characteristics.

I guess the main point of this is to find out what changes the sound and by how much. I mean there's no point in setting the house response flat to within +/- 0.5 dB and think that you can leave it that way when a change in the temperature or humidity can put +/- 8 dB dents and humps in it like it seems to have done. 

So far it seems that you should EQ each session but I'll see what this weeks results come up with by taking more than one measurement in the room but rather throughout the room.


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## jtalden

The comment above concerning the X curve are confusing to me.

Referring to movies only, I thought that the intent was that a theater EQ should be setup to match the X curve and the film or digital track was EQ'ed to be the inverse of the X curve. If done correctly The result would be that the theater would then provide the intended flat response. [The logic being the same as the old Dolby D cassette EQ or the LP RIAA EQ, that is, to try to achieve a low noise and flat response given the weaknesses of the mediums involved at the time (film, tape and vinyl).] 

Since the target of home theater speaker setup is *presumably *intended to provide a flat response the EQ for a BluRay disk does not apply the "inverse X curve" and the result is again to try to achieve a flat response. 

Is this off base? Do I need to try to wade through this again?

[The house curve is another matter and that is where I am struggling.]


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## Wayne A. Pflughaupt

Welcome to the Forum, John!




> Referring to movies only, I thought that the intent was that a theater EQ should be setup to match the X curve and the film or digital track was EQ'ed to be the inverse of the X curve.


No, the X curve was – is – what’s used for both theaters and sound stages. In other words, both the theaters as well as the playback medium (the movies) adhere to the same standard.

Click the “Tech Articles” link in my signature and you’ll find an article about the X curve and home theater. In it you’ll find a couple of other links about the X curve.




> Since the target of home theater speaker setup is *presumably* intended to provide a flat response the EQ for a BluRay disk does not apply the "inverse X curve" and the result is again to try to achieve a flat response.


Unlike a theater, the goal in a home theater is flat response. However, for many people flat response sounds “thin” or “tinny,” sorely lacking in bass response. So a rise in the lower frequencies is enacted to make response sound natural.

Regards,
Wayne


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## jtalden

Thanks!
I got the wrong idea or confused it with something else i guess. I will read through the info you noted.


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## Siamize

Well I run a set of test throughout the building this morning and WOW. While I realise that my initial testing location that I was using wasn't the best I really didn't think that it would vary so much through the room/seating area. I knew that some areas had more bass response but yea. Now I have to workout where to attack next.

Note that for the following response charts the inverse of the Target House Curve has been applied.

Here's the responses at 12 various seating locations (the reasonable flat purple line at about 1dB) was at the previous test location (location where the EQ was set).
http://siamize.vpscustomer.com/sound/100420 - PCCC seating locations.jpg

In this response, I've averaged all 12 the seating locations. Also included is the response in the middle of the seating area (probably the most ideal test location if a single test location was to be chosen) as well as the response when seated at the sound desk. My first comment is that as the sound desk the highs don't response as well as in the rest of the room leading to obvious mixing difficulties.
http://siamize.vpscustomer.com/sound/100420 - PCCC overall.jpg


As you can see the practicalities of having a nice even sound/flat response seems somewhat of an idealistic concept considering I have't even included the wash from the stage foldbacks yet!

My next step will be to EQ it for the centre of the seating location and then then test the various seating locations again. The this centre locations seems somewhat like that average response (ie. areas that need cutting/boosting) (although I use that term "somewhat" very loosely).


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## Siamize

OK analysised the average data for the 12 seating locations and then estimated what EQ changes needed to be made, made them and then tested all locations again. I'm pretty happy with the results actually except for the 1kHz band which I've boosted by 5dB but haven't tested again. Overall the sound is much more natural and less crisp which is to be expected but does sound much more even. Although I am thinking of moving that 2k attenuation point back up to 8kHz to see how it sounds.

Here's the overall responses (with inverse house curve applied).
http://siamize.vpscustomer.com/sound/100421 - PCCC overall.jpg

At each of the 12 location (with inverse house curve applied).
http://siamize.vpscustomer.com/sound/100421 - PCCC seating locations.jpg


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## Siamize

Well I took my advise and applied it and am very happy with the results. From the last tests (100421 which 

were done for a Modern X Curve but applying attenuation at 2kHz) I estimated what EQ changes needed to be 

made at the top end to change it to the Modern X Curve (ie. Attenuated at 8kHz). I'm pleased to say that I 

prefer the sound - much more clarity. For some reason there is now a dip at 250Hz even though I didn't 

change anything in that area but that's not that bad for removing some mud some times. I think that my 

"mistake" of attenuation at 2kHz was due to only selecting one not really ideal spot for my original testing. 

Admittedly it takes much longer and more effort to measure at 12 locations plus a few other non-seating 

locations, but it is definately worth it if you want a real result for your room - particularly if you have a 

rather large room where there are many different seating locations.

There are the results and I've also overlayed the House Curves as the inverse of the House Curves have been 

applied to the responses.











http://siamize.vpscustomer.com/sound/100422 - PCCC overall.jpg











http://siamize.vpscustomer.com/sound/100422 - PCCC seating locations.jpg


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## Siamize

I really don't get it. Today (Tuesday) I went and tested the room again with all the same settings as Friday (See http://siamize.vpscustomer.com/sound/100423 - PCCC seating locations.jpg for Friday's Responses) and the response was just way different on a few particular bands (250, 800, 1000 & 2500 Hz) by up to 7dB. (For a comparison see http://siamize.vpscustomer.com/sound/100427 - PCCC seating locations.jpg).


I thought that I had nailed it to an interference/nodal thing and that the issue would be removed by testing in approximately the same locations (ie. not down to the same inch but rather to the nearest foot or so) and by testing in 12 locations instead of 1 and taking an average.

However it seems to be something else. Any ideas?


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## Wayne A. Pflughaupt

I'd say study your 12 locations for both days and see if you can determine which location(s) is skewing the measurement. Then figure out what changed at those locations between the two days. Near an AC vent that was blowing one day and not the other? Some nearby object in the room relocated, removed or added? Some kind of noise bleeding into the room from outside the auditorium?

Regards,
Wayne


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## Siamize

Wayne A. Pflughaupt said:


> I'd say study your 12 locations for both days and see if you can determine which location(s) is skewing the measurement. Then figure out what changed at those locations between the two days. Near an AC vent that was blowing one day and not the other? Some nearby object in the room relocated, removed or added? Some kind of noise bleeding into the room from outside the auditorium?



It's not any particular one locations skewing as I can normally tell if it is going to skew after about 3 results because it happens at all locations.

All AirCon was off during all testing, and furnature was basically all the same nothing noticable has been moved or changed.

The volume that I'm testing at is very much above any background noise an the room is closed during testing as well.

I was talking to a guy from the city theatre and he said that it sounded like something playing up in the amps.

I've tested it twice this week and it hasn't tried to skew the results. Very strange.


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