# Choosing the correct music subwoofer



## audionub65 (Jun 12, 2010)

I'm new, and this is my first post and I'm new to home audio but I'm here to learn if your willing to help! ^_^

SOOOO, I need a music sub and I can't decide to build my own or just buy the STF-2.

To build my own, I plan to build a JL 12w6v2 or a 12w3v3 but the boxes recommended by the company is made with cabin gain of the car in mind??

Connection: It will be from my sound card, then receiver and then it connects to my sub woofer and speakers.

Questions: I'm open to suggestions and comments, as of now all I know is music is around 30Hz and up and HT audio needs to be VERY low(lower the better), this true?

To me RMS of a car AMP is very different from the RMS you get from a home audio receiver(home audio receiver sounds ALLOT louder).

Why does a HT subwoofer sound bad when playing music?

Hopefully this makes since but here is the rundown: I have no clue what a sub SHOULD sound like outside a car but know it needs to hit every not and sound punchy right??

Thanks for the help!!


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## CharlieU (Jan 26, 2007)

HT subs don't have to sound bad for music. In fact, you will find most subs will perform well doing both. Look for a sub that can maintain a good output down to 20Hz and you should be covered for both music and movies. Ported subs usually do this well, sealed subs can be designed to do it, but watch out, some sealed subs will drop off severely before 20Hz.

Picking a sub is the easy part. Getting it to sound right in your room will be the hard part. There are a lot of good threads on this forum that talk about proper placement, acoustic treatments and EQ'ing. Take a look at those to understand what it may take to get the most enjoyment out of your new sub.


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## mdrake (Jan 31, 2008)

First off, welcome to the shack! You have come to right place! We love helping people build subwoofers. :T

Now for some questions:
What kind of amplifier are you going to be power the subwoofer with and how many watts?
Are you sold on the JL woofers or are you option to other options.
What kind of music do you listen to.
How larger is your room?

Matt


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## audionub65 (Jun 12, 2010)

Right!

I was looking into the O bash amps(the 500watt model)
I'm basically sold on the JL sub since I know what it sounds like and I LOVE QUALITY
I listen to dub step, techno(allot of fast beets that need to be accurate, hence why I went JL)
My room is 13X10 1/2


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## tonyvdb (Sep 5, 2007)

You are correct in that Music is normally done at about 30Hz, Movies go much deeper. Although I agree that JL does make a good sub and DIY can yield poor results until your good at it I would seriously suggest looking hard at SVS, They only sell on line and this way you save as much as half what you would pay in a store for the same quality. Look at it this way, for $600 in the store you would be hard pressed to find a 12" sub thats real quality But not only do you get a PB12NSD from SVS but you are guaranteed to have a sub that is built really well and goes below 20hz without struggling.


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## audionub65 (Jun 12, 2010)

To be honest, I'm scared of buying a prebuilt sub because;

The box is smaller then what it should be
Doesn't get as loud as it can
Doesn't sound musical(especially the logitech z5500, the lower model, a infinity 12" sub(one known to fail allot) all sounded BAD.
Makes port noise faster then a pathway then a small tube?? If that makes sense.

Note: I can't play it to loud since I have a brother next door but more power doesn't hurt.


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## Moonfly (Aug 1, 2008)

Not all commercial subs suffer the limits you mention, and its usually just the budget end of the scale that suffers badly. The JL driver will make a good sealed sub, and will be musical, but a ported one will offer more low down output. No offence to Logitech, but we shouldnt speak of them in the same sentance as the like of a JL powered sub, they are from different worlds.

I think you need to think of what your budget is really, especially if your going to consider commercial designs, and I think you shouldnt just write them off. If your DIY build (should you decide your set on that) isnt really going to suffer budget constraint, perhaps to buying what you need a bit at a time, and size isnt an issue (based on your comment about under-sizing) then I think you should look at drivers that are going to deliver more of what you need with greater ease as the benefits will be obvious. If its a first build though, and especially if music is more important to you than HT, then a sealed sub is a good place to start, not least as you can reuse your components and make a ported one later should you choose to do so.


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## audionub65 (Jun 12, 2010)

This is not my first build at all, I built a JL 12w6v2 ported and tuned to 32Hz by what the manufacturer states and it sounds amazing. I feel like I'm set on building because it is cheaper, and get more bang for the buck.


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## Moonfly (Aug 1, 2008)

In that case then, I would go for a 15" driver if you want to realise a step up in performance, or even the 18" maelstrom. If you have experience, no issues with size, and your happy to fund it, then why restrict yourself to a 12" driver.


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## audionub65 (Jun 12, 2010)

for starters, this is made for music(HT is nice but it will be in my room most of the time and when we watch a movie it will be put into the home audio room were it will be unleashed), I have a brother in the other room, and don't need something like that.

What I would like to do is make a Jl 12w3v3 in a ported box tuned to 22Hz or get some help getting it tuned to a good frequency and see how that works in comparison to other pre-built subs and what is out there. Why that sub? Little less in sound quality but still be beastly loud and for 120 for the sub and about 230 for the 500watt Oamp seems like a perfect match to me or am I missing something?


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## Moonfly (Aug 1, 2008)

A sealed design with a larger driver will still sound excellent, and it will be cleaner that a smaller driver that has to work harder to produce the same material. Ive compared 12 and 15" drivers, and I would go with the larger one everytime. Given you have built the 12" design before, why wasnt it enough?


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## tonyvdb (Sep 5, 2007)

You say that you want to "move" it from one room to another. A sub larger than a 12" will be very hard to move if its built properly. For example the SVS PB13Ultra that I have weighs 160lbs and even the PB12NSD that I mentioned above weighs around 100lbs. These are not something you move at leisure.


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## audionub65 (Jun 12, 2010)

After today, my friend bought 2 jl 12's and had them in a sealed box and sounded amazing! I may now put my JL in a sealed just because it sounded that much better. I hear the each PUNCH of the note rather then the vibration or some weird note( I might have messed up my box but it sounds bad compared to it)

So right now how I see it, I think a sealed would be best unless I'm missing something here


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## tonyvdb (Sep 5, 2007)

A sealed box will give you a smaller footprint but lower spl. If you want high output you dont want a sealed box and it will need to be larger.


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## audionub65 (Jun 12, 2010)

thats the thing i thought I made my box correctly (witch I did) and thought it sounded amazing but when I listened to my friends(he has the most basic JL model) it just punched and hit hard but mine just has vibration but there is some punch but not like his?? IDK if I'm making since or know how it should sound but now I feel like it should be sounding differently. I think I will go down and buy some more oak and build a sealed enclosure and see how that sounds.

Is it because I made it out of oak that it doesn't sound correct? Or could it be my car's frequency is weird?

So a good sounding bass hits every note and has a BIG punch to it? Or is it more like vibrations??

I thank you all for the help I'm getting but I think I need to figure what a good sub is supposed to sound like.


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## Moonfly (Aug 1, 2008)

Its my view that to really do a sealed sub justice, you need a dual driver (or more). A sealed sub using 2 drivers will match the output of a larger ported design but offer the benefits that come with a sealed design while removing any of the issues you will get from a ported design, especially one that has size restrictions applied.

I prefer sealed subs, but they are more expensive, and especially so if you use multiple drivers, as I well think you should. If you had a couple of the JL12's in a sealed sub using an opposed driver alignment, it will give you the sound you describe. From experience, sealed subs integrate into a system better as well, and to boot, they are the easiest design to build as well. They are more expensive when you use another driver, but the increased output and power handling are what a sealed sub really benefits from. Finally, when building your own, you can play with the system Q by altering the enclosure size, and tailor the sound character for either more upper bass punch, more low end grunt, or a balance of the 2.

From what you have put on here, I reckon a sealed dual driver sub would really make you happy, and it will give you a good response right down to at least 20hz, more than enough for your requirements.


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## Moonfly (Aug 1, 2008)

tonyvdb said:


> A sealed box will give you a smaller footprint but lower spl. If you want high output you dont want a sealed box and it will need to be larger.


You can still get high output from a sealed subwoofer, but you will need a HPF to remove the lowest frequencies or you need to use multiple drivers and multiples of the power to suit.


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## ISLAND1000 (May 2, 2007)

audionub65 said:


> What I would like to do is make a Jl 12w3v3 in a ported box tuned to 22Hz or get some help getting it tuned to a good frequency and see how that works in comparison to other pre-built subs and what is out there. Why that sub? Little less in sound quality but still be beastly loud and for 120 for the sub and about 230 for the 500watt Oamp seems like a perfect match to me or am I missing something?


 The JL drivers are good for what they were intended (in car use). 
You can't compare (in car) response with (in-room) response, the added cubic feet of the room requires lots more power from the amplifier and much more air movement from the driver.
Check other subwoofer drivers mentioned on this website especially the CSS drivers at the top of this page. They have extraordinary drivers in the size (10"-12") you seem comfortable with and are almost the same price as JL.
"Parts Express" also has a good selection of drivers from the ultra cheap to the best 18" monsters.
Another very helpful tool/project for DIYers is the WinISD program that is free to download. With that box design program you can optimize any and all drivers in a variety of different sized boxes including sealed and ported. The information gained from playing around with the software is huge.
You're gonna be a success with your project, you asked questions first.


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## audionub65 (Jun 12, 2010)

Thanks guys! It seems I shall go sealed!! That is what I am looking for (Tight and punchy bass)

SO... now the part comes for the sub woofers to choose for my setup. I will look at JL and the SS subs and why I am going with JL is because I got a great deal with them a 12w6v3(for 300 FLAT).

If I do the JL way, should I use the 12w6v3 sealed in my room or my car? The dual subs I am looking at is the 12w3v3 OR the 12w1v2 depending on the deal I can get and will be in my car OR in my room based on what you guys think.

POWER: My car has 750RMS power handling and for my room will be 500 watt O bash amp(or I can get something different/more powerful based on your recommendation). So there is the info and what do you guys think?

I'm leaning to go w6 for my room and 2 JL subs for car

If not to much trouble, what sealed specs should I try for my 12w6v2?

I don't care about trunk space at all, I just want quality!

Thanks again!


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## gdstupak (Jul 13, 2010)

Hello.
I'm new to this forum. I was searching the net for 'musical subs' and came across this thread and decided to join and put in my 2 cents.
First I would like to show you an old article, old but still accurate, about musical subs: well, I would like to show you a link to go to, but this site won't let me because I'm too new, maybe if I separate it into several parts and you can put it together (eliminate all the spaces and go there):
http://www.soundstage.com/maxdb/maxdb200101.htm 

Here are a few direct answers to some of your original questions:
- ....Frequency range of musical subs?..... Classical instruments can play lower than 25hz. Electronic music can play lower. So don't miss out by having a sub that only goes down to 30hz.

- ....So a good sounding bass hits every note and has a BIG punch to it? Or is it more like vibrations??..... Whether the note hits with a big punch should depend on the instrument making the sound and how it was recorded. A loud, obnoxious sub will make everything 'hit hard' no matter the original intent, an accurate sub will reproduce a sound similar to the sound that was recorded. Before I became a quality freak, my first car sub was a mass produced dual 10" band-pass, it always hit hard and loud and shook the car and set off alarms everywhere, I was lovin' it...until I bought a 12" sealed HSU car sub that played accurately. My original box was just a generic 'BOOM' maker, there was no variation in tone, couldn't tell what kind of instrument supposedly made the noise. The HSU sub would hit hard but only when the source called for it, otherwise it sounded like a pipe organ, a kick drum, or a synthesizer.

-..... Difference between musical subs and HT subs?..... HT subs are built for shock & awe effects,, they are not built to accurately reproduce the sound of musical instruments,, they are built to emphasize the frequencies 40-80hz which shakes your room during explosions. Musical subs properly reproduce the sound of instruments (you can distinguish the difference between a tuba, a trombone, a bassoon, a pipe organ),, frequency response is as flat as possible from 20-100hz.

My recommendations:
- Don't just build a box of your own making. Go online and find a plan for a box made for music. The size, shape, structural integrity, and internal baffling all determine the 'Q' factor (this is the inherent frequency response and the 'sound' of the box). 
- Make the box out of the most dense material you can, solid oak is good (that's what my box is made of), also MDF.
- No smaller than a 15" driver (or dual 12"). If your main speakers do not perform solidly down to 50hz, you should also get a 10" sub to cover that lower bass region (my main speakers cover 20k-40hz, my 10" sub covers 60-30hz, my 15" sub covers 40-20hz).
- Sealed box. Not as loud but more accurate and clean.
- Use a good quality equalizer to get that sub as flat as possible. Without an EQ to boost lower frequencies, you're 20hz will be too quiet compared with 40hz. My system is EQ'd all the way from 20khz down to below 20hz: my main speakers have an EQ, and each of my 2 subs have there own special sub EQ's.


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## tonyvdb (Sep 5, 2007)

gdstupak said:


> -..... Difference between musical subs and HT subs?..... HT subs are built for shock & awe effects,, they are not built to accurately reproduce the sound of musical instruments,, they are built to emphasize the frequencies 40-80hz which shakes your room during explosions. Musical subs properly reproduce the sound of instruments (you can distinguish the difference between a tuba, a trombone, a bassoon, a pipe organ),, frequency response is as flat as possible from 20-100hz.


As I have said before this is no longer the case particularly if you are talking about a good quality Home theater sub. I can guarantee that my SVS PB13U will reproduce music better or the same as any so call dedicated "musical" sub. Its all about the design of the enclosure and quality of the driver nothing more.


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## gdstupak (Jul 13, 2010)

tonyvdb said:


> As I have said before this is no longer the case particularly if you are talking about a good quality Home theater sub. I can guarantee that my SVS PB13U will reproduce music better or the same as any so call dedicated "musical" sub. Its all about the design of the enclosure and quality of the driver nothing more.


I apologize if I made it sound as if I thought HT subs sounded bad, the difference between a HT sub and a musical sub has nothing to due with quality, it has to due with each being designed to produce a different sound. I know there are many good subs that can pull double duty for both, such as your SVS, I would love to be able to afford that. My telling of the experience with the old obnoxious "BOOM" box was not meant to show the difference between a HT sub and a musical sub, that was the difference between a low quality sub that was designed to go 'boom,' and a better quality sounding sub. 
The original poster asked what the difference between the two were and I wanted to give him the answer.


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## tonyvdb (Sep 5, 2007)

no apology necessary, Thats what forums like this are for to discuss topics like this. 

My personal take on this is if the sub is built for home theater and is tuned properly it will play music just fine without giving up any quality. a so called musical sub that only reaches down to about 30Hz will however struggle with almost everything you throw at it if you want the full capabilities that some better recorded music can have.


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## gdstupak (Jul 13, 2010)

tonyvdb said:


> My personal take on this is if the sub is built for home theater and is tuned properly it will play music just fine without giving up any quality.


Most HT subs will sound great with music, but an audiophile might not like that hump at 50hz.



tonyvdb said:


> a so called musical sub that only reaches down to about 30Hz will however struggle with almost everything you throw at it if you want the full capabilities that some better recorded music can have.


Yes, that's why I wrote that a musical sub needs to go below 25hz.

No matter what the application, 99% of people would be satisfied with a HT sub, including me who can't afford to be picky. 
Just to emphasize once again, EQ,EQ,EQ. Honestly, it's like the difference between DVD and Blu-Ray. With EQ, everything just pops more and sounds cleaner.


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## Moonfly (Aug 1, 2008)

I've added the link in there for you.


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## gdstupak (Jul 13, 2010)

Thank you.
Actually I was afraid you would banish me for circumventing that rule, and then I go and insult an 'elite shackster's' SVS subwoofer.
I'm off to a great start here.


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## tonyvdb (Sep 5, 2007)

gdstupak said:


> Thank you.
> Actually I was afraid you would banish me for circumventing that rule, and then I go and insult an 'elite shackster's' SVS subwoofer.
> I'm off to a great start here.


LOL no issue at all. 
Im not really sure what you mean by a 50Hz hump, if the sub is designed properly (even a $200 sub can be designed right) there should be no hump at all unless the room is creating the hump.


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## gdstupak (Jul 13, 2010)

The 50hz hump:
As I stated in my original post is one of the major differences between a dedicated HT sub and a dedicated musical sub:
HT subs are designed to emphasize 40-80hz to give more of a whallup for explosions and punches.
A musical sub tries to be as flat as possible.
That's what I mean by,"they are designed to sound differently," that's the Q factor in designing an enclosure. 
Now, subs made for both duties will not have as much of a hump, but it will still have a little one, it will have a medium Q factor. This is the design I went with for my homemade sub.


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## Moonfly (Aug 1, 2008)

Links are fine if they are valid and informative, the rule is more to stop bots posting adverts and the like.

Ive had a read through this now and I have some input. First off, not all HT subs are designed to hit hard in the 40-80 hz region. My case in point would be the SVS PB13U. Its more orientated towards going as low as possible as clean as possible. This actually reduces the amount of upper bass punch it produces, as sealing the sub verifies because the resulting sound is that of a sealed sub with a very low system Q. This nicely brings me to another point. I'm glad to see you pick up on the system Q value of sealed subs. Not many people focus on this, but its incredibly important to the overall sound of the sub (not performance), and how you like you music will greatly influence the best system Q for you. I fear not many people understand this. Now, not all HT subs have the same focus, and some rely on more profound upper bass punch (usually due to requirements for small cabinets or cheap components IMO) to give the perception of performance, when they dont really go al that low.

I'm an advocate of sealed subs, and I totally agree that a ported sub will never match an equal sealed sub. For a sealed sub to match the performance of a ported one, you need to replace the port(s) with another driver. This drives up costs but its the cost of perfection IMO. The fact the second driver gets powered makes a huge difference, and Ive come to the conclusion all sealed subs now need to be a minimum of dual driver designs to excel.

My biggest issue with ported subs is really that for mega performance, the cabinets are usually very large in comparison the the volume you would present the driver with in a sealed sub with a .7 targeted system Q. For me this robs them of musicality, and reducing the box size robs them of performance so for me its not possible to win that battle without making a very large multi driver sub with ports that will probably be impossible to fit in the cab, even then, sound output from a port is just not the same as sound produced by a driver. For a start, a port is always smaller in diameter than a driver, which turns a waft of air into a jet of air, so air movement is changed when producing low frequencies, and this changes the net result in a way I find it incredibly difficult to put into words. Then if the volume is very large for driver, the lower Q sound makes the bass a bit to much of an effect sound than meaty bass sound.

These comments are of course my own personal feelings, but for me porting is a way of tricking free performance from a design, and while it works, for me its like the difference between having the real thing, of an imitation, even if the imitation is very good. FYI, the sub I built for my self uses 2 15" drivers, and is eq'd with a response that measures flat to 5hz, :T although I ignore results below 10.


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## tonyvdb (Sep 5, 2007)

gdstupak said:


> HT subs are designed to emphasize 40-80hz to give more of a whallup for explosions and punches.
> A musical sub tries to be as flat as possible.
> That's what I mean by,"they are designed to sound differently," that's the Q factor in designing an enclosure.
> Now, subs made for both duties will not have as much of a hump, but it will still have a little one, it will have a medium Q factor. This is the design I went with for my homemade sub.


Not sure I can agree with that, the ultimate goal of any sub is to produce a flat response throughout its frequency range. Musical or home theater dose not matter the only difference is how deep a sub will go and how much SPL can be delivered through its range. Remember that the room plays a huge role in how the sub will sound acoustics and dimensions are crucial as well as placement. 
This also brings up the "speed" of a sub conversation and is irrelevant as the driver will move as fast its given power there really is no such thing as a slow or fast sub.


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## Moonfly (Aug 1, 2008)

I know of sealed subs with HT intended applications that focus on more upper bass punch, like the MK ones for example. I actually think the opposite is true of ported ones, but neither are designed to have an eventual response curve that is humped at 50hz. If anything a HT sub would benefit more for having a slightly low end hump (due to ears decreased sensitivity at lower frequencies). Driver speed isnt really an issue, but larger drivers do have a harder time accelerating and decelerating due to having to move more air and being heavier. This is offset somewhat by that fact the driver doesnt have to move as far, so the length of stroke that is acceleration or deceleration is a smaller amount. The problem only really comes in with poorer quality drivers where the cone isnt as stiff, or motor force is much smaller for example, and the net result is then distortion and overhang, which is what makes a sub sound slow to respond. Calling it speed is technically incorrect, but I understand the point being made. 

What is really needed is more education in distortion. IMO the are two kinds of distortion, the obvious and the non obvious. Obvious distortion is the sound of a driver bottoming out or farting as the sound distorts, or the air from a port starting to chuff as it exceeds max velocity, or a tweeter sounding like its buzzing when its blown, or the sound of an amplifier clipping and so on and so on. The non obvious distortion is that of an over boomy sound due to excited room modes, or a slow sounding driver due to distortion created by the driver being worked beyond its comfort zone. FWIW, I actually believe is more likely you will hear more distortion from sealed design than ported ones, at least at the lower end of the market with HT applications. Most people can identify the obvious distortion very easily, but picking up on the non obvious is a lot harder to the untrained ear, and only the use of a better sub educates. It is quite possible to be unhappy with your subs sound, and for the reason to be this non obvious distortion, but Ive seen many people eyeing up an upgrade because their unhappy, but without being able to put a finger on the distortion characteristics. A few people have commented on how my sub doesnt sound as loud as their when I really turn it up, while also obviously being just as loud. I point out to them that its how cleanly the sub is producing these low frequencies that makes very high volumes so bearable.


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## gdstupak (Jul 13, 2010)

Wow Dan, you sound like the articles I was researching 9 yrs ago to build my sub, very well said.
I'm envious of your sub. My sealed single 15" (9 yrs is too long ago to remember what Q I went with) is eq'd flat down to at least 20hz, I don't have test tones lower than that....but, wow, to be able to say flat down to 5hz!
"...but for me porting is a way of tricking free performance from a design, and while it works, for me its like the difference between having the real thing, of an imitation, even if the imitation is very good.." I've always thought the same of this and also the design of combining a small (6") driver inside a small cabinet with a crudload of power, such as the Bose AccoustMass box, it's fake bass.


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## gdstupak (Jul 13, 2010)

".....A few people have commented on how my sub doesnt sound as loud as their when I really turn it up, while also obviously being just as loud....."
Years ago I started dreading going over to other peoples houses to watch movies or listening to music on their systems, they've always got that "Loudness" button turned on.


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## Moonfly (Aug 1, 2008)

The Bose modules arent subwoofers, but Bose dont claim them to be, so thats OK really. They are claimed to reach 50hz, which is respectable of a mid ranged tower speaker, so are a good solution for some given the compact form, especially when we consider the distortion swallowing claimed characteristics of the module. Still, its no substitute for a true subwoofer of just about any price level. I can see the draw of ported designs, and would probably consider one myself for a HT only setup, but as I'm love my music, and Ive never found a ported sub I'm happy with, its sealed all the way for me.

Saying my sub goes flat to 5 hz should really be taken with a inch of salt. Sealed subs dont use HPF's so dont have any low end signal removed, ad they roll off much more naturally and gradually than a ported design. Measuring a very low response is all well and good, and not that difficult, where the proof of the pudding is, is when you turn the subsystem up, and start to look for its limits. My amp clips at reference level with a sweep beginning at 10 hz, so my amp wont sustain that frequency at reference levels (115db max output), but the drivers do handle it very well, and a 10hz sine wave at 95db wasnt an issue with the drivers looking very comfortable indeed. I have more headroom then I need, and really that what it should be all about. Ive tried many a film at reference level, and my room seems to groan more than the sub :devil:

Something that may interest you is REW. Its good for measuring your systems response, but it also has a few tone generators, which will make delving below 20hz very easy :T. Check it out.


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## Moonfly (Aug 1, 2008)

gdstupak said:


> ".....A few people have commented on how my sub doesnt sound as loud as their when I really turn it up, while also obviously being just as loud....."
> Years ago I started dreading going over to other peoples houses to watch movies or listening to music on their systems, they've always got that "Loudness" button turned on.


The loudness button attempts to apply a loudness correction curve to the response to adjust for differing sensitivity at lower frequencies at lower volumes. The buttons are really not very good at hitting this goal, as really the feature needs to be more dynamic and the applied response curve needs to change depending on the volume. Newer AVRs do have these features, but those that do and dont like them are mixed, I for one never use these kinds of features, instead preferring to just turn the system up a little


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## gdstupak (Jul 13, 2010)

Moonfly said:


> I know of sealed subs with HT intended applications that focus on more upper bass punch, like the MK ones for example. I actually think the opposite is true of ported ones, but neither are designed to have an eventual response curve that is humped at 50hz. If anything a HT sub would benefit more for having a slightly low end hump (due to ears decreased sensitivity at lower frequencies).


When I was researching subs 9 yrs ago it seemed to be common knowledge that HT subs emphasized 40-80hz.
This is from the article that I linked to earlier and I've got HT magazines that wrote about it:
"... Home-theater subwoofers are designed to move a lot of air in the 40-80Hz range to make explosions and the like have that solid, realistic character that can make home theater so satisfying. When you apply that to music, you end up with too much 40-80Hz energy and not enough below 40Hz...
Never trust a sales person who says a given subwoofer is equally good for music and movies. ...."


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## Moonfly (Aug 1, 2008)

Things have changed a lot in the last decade, not least in driver technology. On top of that movies didnt really try to go below 20 hz, but now its the norm. The low end drop off no longer is a necessity, and the idea of a humped response over 40 hz is all but gone. Generally sealed subs dont display any kind of hump like this, which may be why they were always considered best for music, but I wanst really into things so deep tn years ago. Now-a-days, a flat response is the target, and subs are usually rated down to a certain frequency, with a particular frequency at a given volume being the determining limitations. High end sealed subs use no bottom end limits, but ported ones do due to the way a port works. Only large very low tuned ported subs have no real low end limit, but again, a sealed sub can easily match this level of performance, and in many cases exceed it, if the port is replaced with a second powered driver, and the drivers are of sufficient quality and have plenty of power behind them, not least for the implementation of electronic eq, which is fast becoming the norm.

FWIW, I believe I now have a sub that is equally good with music and movies, but getting here took me a long time. To match it commercially would be incredibly expensive though.


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## gdstupak (Jul 13, 2010)

Moonfly said:


> The loudness button attempts to apply a loudness correction curve to the response to adjust for differing sensitivity at lower frequencies at lower volumes. The buttons are really not very good at hitting this goal, as really the feature needs to be more dynamic and the applied response curve needs to change depending on the volume. Newer AVRs do have these features, but those that do and dont like them are mixed, I for one never use these kinds of features, instead preferring to just turn the system up a little


Your description of the "Loudness" button is not what I was referring to. I'm talking about the button they started putting on the cheap AVR's back in the 90's which simply increases bass no matter what the volume level, it makes it sound louder. 
My new Onkyo has the "THX Loudness Plus" & "Audyssey Dynamic EQ" which is the feature you describe. I haven't played with the THX version yet, but I tried the Audyssey's. It sounded well balanced at reference levels but had waayyy too much bass at lower volumes, after several hours of listening at low volume it was hurting my ears. For my system, the Audyssey's feature is too dynamic.


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## gdstupak (Jul 13, 2010)

Moonfly said:


> The loudness button attempts to apply a loudness correction curve to the response to adjust for differing sensitivity at lower frequencies at lower volumes. The buttons are really not very good at hitting this goal, as really the feature needs to be more dynamic and the applied response curve needs to change depending on the volume. Newer AVRs do have these features, but those that do and dont like them are mixed, I for one never use these kinds of features, instead preferring to just turn the system up a little


I just reread this.
Are you saying that the goal of the old "Loudness" button was the same as the new one, but in the old days, it didn't change with volume change, so you would manually turn it on when listening at low volume, and turn it off with higher volume? Now that makes sense, I always thought it was just a gimmick manufacturers used to make their systems sound louder at all volumes. Well, my friends have that button "on" all the time.


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## Moonfly (Aug 1, 2008)

The idea ofthe loudness button was the same idea as with Audyssey DEQ and similar features, but was just a basic GEQ type manipulation of the signal, gradually boosting lower frequencies, but still maintaining the GEQ profile you have active. It does make things sound louder, and you will notice it adds much more bass to the sound. Its just a blanket boost though, nothing intricate. Its not very accurate, but did its job without really requiring any processing power. Most people I know have it on all the time, including myself on poor systems. I think it works well in a car, but wouldnt for a proper HT.


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## acoustat6 (Mar 7, 2008)

Hi Mooonfly, you said "FYI, the sub I built for my self uses 2 15" drivers, and is eq'd with a response that measures flat to 5hz, although I ignore results below 10."

Can you post an REW of this? I would love to see a response that low. I doubt there are many system that go that low. Are you using a Behringer for EQ? How flat is the response? + or -, 3 to 5db? My subs are flat to 9hz with my house curve.:hsd:

Thanks,
Bob


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## Moonfly (Aug 1, 2008)

The only saved result I have is the one attached. I wouldnt pay to much attention to anything below 10hz anyway as my measuring equipment isnt accurate enough IMO. Saying that my sub is a sealed sub with no HPF to filter out low frequencies, so in theory should be able to produce right down to 1 hz. The reality actually is that even if it is producing frequencies below 10hz, even a sub like mine wont be able to produce them at levels we can hear properly, especially when other frequencies are being produced as well. Its easy for a tool like REW to pick up 10hz being played out at 75 db, but its entirely inaudible to my ears on its own, although its effects on the audible range do make a difference. Its also one ting for a sub to produce extreme low frequencies at fairly low levels for simple measuring, but doing it at high levels is an entirely different thing. A subs performance figures need to be put into perspective, 10 hz isnt a big deal till you put an spl figure on it and if you want to start getting technical, then even if your sub can hit 10hz at very good spl levels, it can be picked apart once you start to look at distortion levels etc.

My sub measures flat upto 105db max at 10hz and over in my room, so its plenty performance for me. Of course, even performance itself is only part of the picture, as sound quality is easily just as important to the eventual product you create. Ive rambled on enough, but hopefully it helps put a couple things into perspective. If I can book some living room time, I'll do another graph from 1hz up.


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## gdstupak (Jul 13, 2010)

Ramble on.
You always write interesting and informative posts.


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## acoustat6 (Mar 7, 2008)

Moonfly said:


> The only saved result I have is the one attached. I wouldnt pay to much attention to anything below 10hz anyway as my measuring equipment isnt accurate enough IMO. Saying that my sub is a sealed sub with no HPF to filter out low frequencies, so in theory should be able to produce right down to 1 hz. The reality actually is that even if it is producing frequencies below 10hz, even a sub like mine wont be able to produce them at levels we can hear properly, especially when other frequencies are being produced as well. Its easy for a tool like REW to pick up 10hz being played out at 75 db, but its entirely inaudible to my ears on its own, although its effects on the audible range do make a difference. Its also one ting for a sub to produce extreme low frequencies at fairly low levels for simple measuring, but doing it at high levels is an entirely different thing. A subs performance figures need to be put into perspective, 10 hz isnt a big deal till you put an spl figure on it and if you want to start getting technical, then even if your sub can hit 10hz at very good spl levels, it can be picked apart once you start to look at distortion levels etc.
> 
> My sub measures flat upto 105db max at 10hz and over in my room, so its plenty performance for me. Of course, even performance itself is only part of the picture, as sound quality is easily just as important to the eventual product you create. Ive rambled on enough, but hopefully it helps put a couple things into perspective. If I can book some living room time, I'll do another graph from 1hz up.


_Posted via Mobile Device_


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## acoustat6 (Mar 7, 2008)

hi moonfly I wold like to see a full range graph. I see that you do not have a house curve, are you going for a flat response from 20 to 20 k ? You sY that you cannot hear 10hz, when do you start hearing freq? If 10hz is not audible how does it make an audible difference? Bob if the first 100db suck why continue?
_Posted via Mobile Device_


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## Moonfly (Aug 1, 2008)

I do just go for the flat response, as I dont feel I need any more than that gives me. The question on 10hz is a good one though. Although I cant directly hear 10 hz as a tone, I can hear the effect it has in the room, and it certainly has an audible effect on the resulting sound from the sub. Once I get up close to 20 hz, I can hear it, but its not sound as such, more an effect your ears can pick up. Once I get to about 22hz I can begin to hear what I recognise as sound. The sub sonic LFE has a profound effect on the overall sound, and I know when its not there, and now I have a sub that can produce this stuff without farting, it an experience I really enjoy and would be without.


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## acoustat6 (Mar 7, 2008)

Hi Moonfly, I prefer my system with a nice healthy house curve to mimic the Fletcher Munson curve, I am up 15db at 20 to 30 hz with extension down to less that 10hz.:yikes: I do use a 20hz filter and you can see it effect on the response in one of the graphs. I use the filter because I use my system for vinyl only, to eliminate the inherent subsonics.

The first graph shows 15 to 150 hz no smoothing

The second graph shows the two crossover points with one octave smoothing in my three way system.

The third graph shows, red line 20hz filter off , green line with 20hz filter on (sub only), blue line is the mid range speakers with crossover points (all with one octave smoothing).

I do hear 10 hz:T with no distortion.

All measurements with calibrated mic.

I am still not sure why you say can't hear the freq but then it has an audible effect? hmmmm:scratch:

Bob
If the first 100db suck why continue?


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## gdstupak (Jul 13, 2010)

"I am still not sure why you say can't hear the freq but then it has an audible effect? hmmmm"

I can't discern an actual sound below about 25hz but my ears and body can feel the pressure.
Several years ago when first playing with my eq's and subs, I was just playing with the <20hz - 40hz range at about 80decibels for 30mins. I didn't wear earplugs because it didn't sound loud and most of it I couldn't hear much of anything, but about 15mins after it was done my ears were killing me. Since then I've always used earplugs.
Same goes for super tweeters that play higher than human hearing, I believe they have some kind of effect on our listening experience.

I prefer a flat response.


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## Moonfly (Aug 1, 2008)

As gdstupak says, there isnt really any traditional sound as such, but you can make the tones out etc. Ive run 100 db sine waves at 10 hz and can hear nothing, but there is a slight 'something' I can detect and the effects on the room are obvious. Ive had subs unable to produce these frequencies and the difference in the perception of depth is night and day. With the very low sub sonics missing, its like some of the sound is missing from the overall sound being produced, and this is what we can hear/detect, which is where the real difference is for me. Simple things like doors slamming are transformed as an effect when your sub can produce these very low frequencies.

Acoustsa6, you should do a couple tests. Run a 10-20 hz sine wave from the 75db shelf and slowly increase volume till you can either hear it or your system limits and note the sound of it (I'd be very surprised if you can actually hear a 10hz tone at 100db on its own). Then try running some material that doesnt have any properly low frequency stuff in it, and mixing the low frequency sound in to see how its addition affects the overall sound, its quite interesting to do, and as one person I showed this to said, its like a bit of a science lesson.


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## Moonfly (Aug 1, 2008)

Well Ive just done another quick sweep. Ive actually not had my sub in for a few weeks and I changed the drivers for new ones a short time ago so this was quite interesting for me. As you can see, I need to re-do Audyssey, but I am moving house next week so was putting it off. In any case, I've got a week of fun I guess . The graph is below, and I suppose I could say its good to 4 hz :devil:, should you wish to pay attention to it, which I personally dont.


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## acoustat6 (Mar 7, 2008)

Hi Dan, You said you posted a full range sweep, I do not see that anywhere. I must be missing something! I assume that you are measuring with a calibrated mic, is that correct? 
Thanks,
Bob


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## Moonfly (Aug 1, 2008)

I attached a 1-200 hz sweep of my sub in the previous posts, can you not see it. As for the meter, I'm only using the RS meter, hence why I completely ingore anything below 10hz anyway. Is this what you wanted, or something else?


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## acoustat6 (Mar 7, 2008)

Hi Dan, I do see the REW out to 200hz. I was thinking fuller range out to at least 1000hz. so 10 to 1000hz with no smoothing and then the same REW with one octave smoothing.

The RS meter is fine out to 1000hz. 

I am now using a calibrated mic and when I originally compared it to my graphs with the RS meter the difference was negligable in the ranges we are talking. Though below 40hz the RS meter was not as accurate but still very usable.

Thanks,
Bob 
PHP143


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## Moonfly (Aug 1, 2008)

Got ya, I'll try get one done later today, I'll run a 30 second sweep right upto 5000hz if you wish, you'll be surprised how high these sub drivers extend up, and a recent SVS EQ-1 sweep gave a flat response from the sub right of the chart :T

Out of interest, which drivers do you use?


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## acoustat6 (Mar 7, 2008)

Hi Dan, for my subwoofers in my three way system I am using custom made Eminence 8 inch drivers. The drivers were custom designed for this project where myself and two other sets of subs were made. They are in a sealed enclosure. There are 16 drivers with 8 forward and 8 rearward facing drivers per side for a total of 32 drivers in stereo.:R We had 100 drivers made to our specs so that way we had three sets of 32 drivers for a total of 96 drivers with four drivers left over for spares. The price savings was substantial. Pictures attached.

The subs are driven by two SAE 2400L amps at 200wpc. 

Bob,
If the first 100db suck, why continue?


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## recruit (May 9, 2009)

Are you sure they are big enough Bob?


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## acoustat6 (Mar 7, 2008)

Hi Recruit, I am sure they are big enough. That was the whole exercise. We had tried many subs to mate with my Acoustats and the other two sets are mated to big Soundlabs. They needed to be dipole to match the electrostats and they needed to be a line source also. The eight inch drivers are perfect for a sheet of plywood and quick enough to match the electrostats. So they work quite well. They also have enough output to go very low at high enough SPL, the design goal was reached.:bigsmile: We made sure we never run out of subwooferage! These do go very low with enough output that you do hear below 20hz test tones:yikes:

Though they do take a bit of EQ to get there. I use a Marchand Bassis to deal with the inherent rolloff of a sealed enclosure and a Behringer for the acoustics issue.

First REW is with no smoothing and the second REW is with one octave smoothing.

Bob, 
PHP143
If the first one hundred db suck why continue?


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## recruit (May 9, 2009)

That is a very nice response Bob and I bet they sound awesome in terms of output, have you measured there full output capability or do you get blown away by all that air that is being shifted :hsd:


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## JoeESP9 (Jun 29, 2009)

acoustat6 said:


> Hi Dan, for my subwoofers in my three way system I am using custom made Eminence 8 inch drivers. The drivers were custom designed for this project where myself and two other sets of subs were made. They are in a sealed enclosure. There are 16 drivers with 8 forward and 8 rearward facing drivers per side for a total of 32 drivers in stereo.:R We had 100 drivers made to our specs so that way we had three sets of 32 drivers for a total of 96 drivers with four drivers left over for spares. The price savings was substantial. Pictures attached.
> 
> The subs are driven by two SAE 2400L amps at 200wpc.
> 
> ...


Are those line source tweeters? If so what are they made of?


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## acoustat6 (Mar 7, 2008)

Hi Recruit, I have not measured their output capability, but suffice to say its enough! I do play/tune my system to 83db at -20dbfs. I only listen to vinyl and employ a 20hz filter to reduce . 

Hi Joe, the line source speakers are Bohlender Graebner Neo 8 ribbon tweeters. There are 9 drivers per side, wired for 4 ohms. REW graph of the two crossover points attached, with one octave smoothing.

Bob,
PHP143


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