[poseidonsvoice]

I really hope you're kidding.  This is the WORST advice I've ever seen in the acoustic circle.  It's a FACT that it will sound better.  There is no denying it.   


What is your position within audio?  I need to know what to stay away from. 

+1.

Best,
Anand

[RDavidson]

+1.

Best,
Anand

-1 Do people not read through threads and others' responses (addressing what has been said and misinterpreted), before posting a completely pointless response of their own?

[*Scotty*]

Another vote for multiple subs. Easiest thing in the world to, borrow a subwoofer with extension to 20hz, place against the back wall of the listening room and operate 180 degrees out phase. This should help flatten out the response curve. The suck out at 150HZ could be some kind of floor or ceiling bounce cancellation. Also depending on how far the speakers are located from the front wall it could also be a cancellation problem resulting from a multiple of the distance the speakers are from the rear wall. I also have a notch at the about same frequency which is made doubly bad by a combination of two walls that are multiples of the same frequencies wavelength away from my speakers.
 If the out of phase sub-woofer located on the rear wall helps flatten out the frequency response below 150Hz you have a clear direction to go.
Either place multiple small subs around the room ala Duke Lejunes swarm system or two subs at the rear wall of the room, 180 degrees out of phase. It appears that the Behringer iNuke amplifiers with DSP/variable digital delay built in, will allow you to cancel out the bass waves coming towards the rear wall before they can reflect off of the wall and cancel out the bass which causes most of the peaks and nulls see in the bass response curve.
Both approaches will even out the bass response curve everywhere in the room instead of just at the listening position.
You might measure the speakers with no room treatment to get a base line on how bad it is and then experiment with room treatment location if possible. Maybe relocating the room treatments will improve their effectiveness. If you are using the REW measuring software you might look at the RT 60 values which indicates how long it takes the bass energy at various frequencies to decay down by 60db you also look at the RT 30 values.
As far as the vocal intelligibility is concerned, the sheer amount room treatments may have impacted how they are perceived as an unfortunate unintended by-product of trying to solve the bass problem.
One question, is your listening room located in a basement?
Scotty

[Tyson]

Bass traps are kind of worthless if they are not tuned to absorb at the problem frequencies, so they might actually be making things worse.  Multiple subs is the way to go. 

[Vapor Audio]

What about the raging null at 150HZ+ ? That is around the vocal range correct?

That's floor bounce, for all intents and purposes disregard.  Move your mic up or down a foot and see how that suckout changes, it's just a measurement artifact. 

A couple thoughts.  Room treatments will not 'fix' a speaker.  And measuring bass in room is at best, inaccurate. 

So to combine those two points, it's possible your speakers are simply way out of balance and are voiced to be way too bass heavy.  Room treatments will not change that if it's the case.  Also it's very possible that things like that big bass bump shown around 30hz don't really exist. 

The proper way to measure would be 2 different data sets:
- The speakers in a much less room influenced environment, like the back deck.  Measure at 2m with a gated and ungated with complex smoothing.  That will give you a good idea of what the speakers are doing.
- Then measure the speakers in the room, but not FR, measure RT60 and similar energy storage.  That will tell you what the room is doing. 

Either your speakers aren't doing what you want, or the room isn't.  Or both.  But until you separate the two pieces you'll just chase your tail.

[Vapor Audio]

Bass traps are kind of worthless if they are not tuned to absorb at the problem frequencies, so they might actually be making things worse.  Multiple subs is the way to go.

That's true, and not true ... depending on the definition of bass trap. 

Many people think 2" wall panels are bass traps, they're not.  Bass trap means bass has similar absorption numbers to other higher frequencies, that means much thicker than 2" panels.  You won't make things worse with even broadband absorption of a real bass trap, but you can make things worse with too much narrow band absorption. 

Can't remember Chris if it was in this thread or an email, but I did suggest removing some of the thinner panels from the room that primarily absorb 200hz and up.  See if removing some of that narrow band absorption will help to bring up the midrange/treble, and help to balance things.

[*Scotty*]

If he can move the measuring location even a few inches and measure a completely different response curve below 150Hz we know that the room treatments have had very little effect on the bass resonance behavior of the room.
 I don't think he has too much speaker for the room, as it doesn't exactly look like he has so much room gain below 100hz that his bass has a subjectively louder quality than the rest of the frequency range. Of course I could be wrong having never heard his system in his room.
Did Chris describe his room as sounding kind dead from mid-range on up.
Scotty

[Vapor Audio]

If he can move the measuring location even a few inches and measure a completely different response curve below 150Hz we know that the room treatments have had very little effect on the bass resonance behavior of the room.

The FR is going to change as you move around the room, effective room damping or not.  That's why looking at decay times is a much better indicator of how the room is performing, FR is room+speakers and that's 1 too many variables. 

I don't think he has too much speaker for the room

The "too much speaker for the room" ideology for the most part is a myth.  A 60hz wavelength is 18' long whether it's coming out of a 5" woofer or an 18" woofer.  The speakers balance is what matters.  The only truth to the myth is that larger speakers will tend to have woofers close to the floor which increases gain, and potentially larger speakers will be closer to rear and side walls, again increasing boundary compensation. But that's not a function of the size of the speaker, the same would be true if you put a monitor with identical FR balance in the same room location.

as it doesn't exactly look like he has so much room gain below 100hz that his bass has a subjectively louder quality than the rest of the frequency range. Of course I could be wrong having never heard his system in his room.

It's hard to say for sure looking at a small image on a 20db scale, but to me it looks like the bass level is about 6-10db up from the average midband level.  That's some pretty serious imbalance. 

[G Georgopoulos]

Hi Vapor

Put the woofers of your speakers close to the floor,worked best for me,it acts as a baffle for bass
the mids place them close to the tweeter and the tweeter at the top of your speakers
great technigues...

[kingdeezie]

So, a lot of information in this thread.

I don't have any thinner panels in the room. Most of my panels are listed as bass panels by GIK acoustics. I only have one panel that is actually a reflection panel.

The rest of my room is mostly Monster and Tri Traps, with some 244s as well.

The problem is not the midrange or highs at all. It is 100 percent bass. There are definite peaks and valleys that I can hear throughout music as I am listening. It doesn't sound tight, punchy, or even.

Now, of course, unless the speakers are broken (doubtful), then I doubt that is the problem. Many people have these speakers in their rooms, and have presented with significantly better graphs then above in their rooms.

I live in a townhouse, and the room is tiny. I don't think multiple subwoofers is really going to be a viable option.

I think at this point, if I can't fix the problem by positioning, I think I have to get out. Maybe get a headphone setup or something like that.

Its been years of trying to get this room to sound right, and it just isn't fun anymore.

[JRace]

Why would you give up completely?

I would start with removing all treatments and measure again.

[Tyson]

JRace is right - you've never measured your room without any treatments.  Best to do that first, then add back the treatments, one at a time, listening and measuring as you add each one. 

Using multiple subs is one way to address intractable room interactions.  Another way is to use OB bass instead of closed box bass.  OB interacts with a room quite differently than box speakers.  I do think that a line source is probably a poor fit to a tiny room. 

At this point I think you have 2 options:

1. Stick with your current speakers, and use a combo of acoustic treatments and EQ to get it sounding decent.  If you go this route, I'd strongly continuing down the measuring path we've outlined here.  In addition, once you get speaker position and listening position optimized (as much as possible), check out the miniDSP DIRAC - it is the most sophisticated (smartest) room EQ solution I've seen.

2.  Try an OB solution.  I'd recommend starting with something cheap and super easy, like the Hestia project documented right here on AC - http://www.audiocircle.com/index.php?topic=108003.0 I think you will be surprised how well OB's do in the bass region compared to box speakers, especially in a room like yours. 

[Alex Reynolds]

First off - you have GIK products. Definitely feel free to send me an email and I can work you through getting the best out of what you have. My email is on our contact page, or just my first (dot) last initial @gikacoustics.com. To make a couple of quick points:
Your measurements are actually not nearly as bad as many many other measurements we see every day. Some of the major issues are large dips which can, often, be solved by finding better speaker or listening positions (or both). Also, you're only viewing the frequency response graph - which is the graph that contains the least amount of information about your room to look at. The waterfall (and similarly the spectogram) inside REW can tell you a lot more about the sound in the room. For a more in depth discussion on waterfall graphs and decay times, see here: http://www.gikacoustics.com/understanding-decay-times/
Decay times are largely the biggest factor in how we perceive the sound of a room, and is likely why, even though your frequency response wasn't perfect (it never is), the room still sounded excellent to you - because the decay was controlled well. Know that even professional purpose built studios will have +/-10 dB at listening position throughout the range.
Also note that, depending what you're looking at, you usually want to take measurements with single speakers at a time - not both - otherwise you can introduce comb filtering to the measurement that actually isn't in the room.
Dips around 100-200 Hz are normally caused by SBIR, which you can read up on here: http://www.gikacoustics.com/speaker-boundary-interference-response-sbir/
Changing the position of speakers or putting panels between speakers and wall boundaries can reduce these effects.
Of course like I mentioned, please drop me an email. I just wanted to pose some solutions and ideas to the thread so if others wander in with the same issues and questions, they aren't lost!

[Hipper]

kingdeezie - I suggest you accept Alex Reynolds offer. I used their advice in the past and am very happy.

GIK sell Soffit Traps which absorb deeper than Tri-traps.

I too used REW to help get my room better. This is what I did:

First I measured with REW and microphone to get a reasonably accurate picture. Then I use test tones and my ears to finish. Then I check with music.

With REW I place the microphone (m/f) exactly where each of my ears will be when listening. For measuring the left speaker, the m/f is placed where the left ear will be.

For finding the best speaker and ear positions, I only use 20-500Hz plots and am looking for the smoothest response; that is fewest peaks and dips. Make a plan of the room and mark the positions of the speakers and listening chair/ear/microphone for each measurement. Unless you have side firing woofers you needn't worry about toe in yet. Use just one speaker to start with and then when you've found the best position(s) for that, try the other one. Start off roughly where you think it might sound good, measure, make notes, then move speaker, measure etc.. Use large movements of the speaker to start with - say one foot - and then home in on the best areas with smaller movements. However even the best location will leave some problems. The object is to minimise them (I tame the worst peaks later with an equaliser). The dips I have, which look awful on the charts, do not seem to have an impact on the sound. This illustrates a key point, as John Casler tried to point out; these charts are only a guide to getting good sound. For getting the best sound for you, you must use your ears.

Microphones don't hear like your ears. For one thing your ears hear differently as you age, or suffer hearing damage. For another our ears (or rather our brain) can differentiate sounds. Microphones pick up everything. Indeed in my room I couldn't rely on measurements of 50Hz and below because of background noise (from traffic and other things I presume which I hardly notice. REW can measure background noise).

To finish off the measurements then, I use test tones and my ears. I play a full run of 1/3 octave test tones and write down how they compare with each other. I did this for both speakers at the same time. I then adjust my equaliser and repeat. In this way if you have a weakness in hearing this should cover it. I can't hear much above 10kHz, and 6.3 and 8kHz require a 4dB boost to be level with other frequencies.

Then I play music. I found that a very few tracks were boomy with some bass and, using test tones which go from 10-300Hz in steps of 1Hz, which I got from here:

http://realtraps.com/test-cd.htm

I found that 42 and 43Hz had peaks. I was able to knock these down with my equaliser. Incidentally with these test tones I found the large dips had no effect on the sound. Perhaps they are so narrow as to have little effect.

I'm not saying that all this has resulted in the world's best listening experience, but what it has done is improve what I hear from my system. It took me some eight months to get to what I have now. I found there were two speaker and ear locations in my room that gave the best measurements. These corresponded to roughly 'the thirds' and 'the fifths' - speakers and ears one third or one fifth in from each wall and ears the same from the back wall. After a four month trial I found 'the thirds', whilst interesting for three dimensional sound, never seemed quite right. Either this was because I hadn't done it right, or because the Red Book CDs I play - mostly studio recordings - just didn't offer the right information. So now I use 'the fifths' for a wider but shallower soundstage, and that's what I prefer.

Room measurement is complicated but I consider it essential for adjusting speaker and listening positions. Ultimately it must be based on what you hear and how the music sounds to you.

[kingdeezie]

Thanks to everyone that responded in this thread over the last few days. Ive been fighting off a stomach bug for the last few days, so I haven't had a lot of time to mess with the speaker set up.

Alex, I will definitely send you an email to see if there is anything I can do with the traps I have now that might improve the response. I have a combination of monster traps and 244s behind and to the side of the speakers on both sides.

I am hoping to feel better by this weekend, that way I can get some work done around here to try and improve the response.