Room treatments


i was watching YouTube vids on "the quietest room on earth" and am wondering how I might get close without screwing up the aesthetics/functionality of my room. I made skyline diffusers (24"x24") and they definitely help. I’m going to make a giant one (48"x96") and bass traps next. Anyone have more suggestions? More diffusers? Foam panels? See my profile pic for what I currently have if you want. Suggestions are appreciated!
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read the Master Handbook of Acoustics

and BTW, you don't want the quietest room...
Thanks for the heads up on both. I know I can't get my room super quiet but I'm going for as quiet as possible Ima 117 year old highwater craftsman home with 10ft coved ceilings that is really noisy. I'd like to try to get it as quiet as I can and work backwards. So, I'll check out that book and see what's up.  Thanks
noisy from traffic?  or?
Just echoe-y. I guess I'm just trying to get the most out of what I have. I can look past traffic and other outside noises but as my system is pretty exceptional (to me) I'm moving toward maximizing the room.
Two areas where I had great success are

1. Behind the listening position I installed an 8ft vinyl blind that dropped down only 15 inches

2. On top of a book case (close to the listening position) placed a layer of 1" foam with a thick layer of vinyl on top

Those two stoppers the bulk of reflections issues I had in that room and were pretty affordable and quite invisible (the blind was behind some drapes

Turns out vinyl is one of the better materials for converting sound into heat

volume control can kill ambient noise.

people should definitely work on their listening rooms

walk around clapping your hands and post what you rear - you may need more absorption

also, how close to a rear wall is your listening spot?
Great ideas williewonka! I definitely have some places that I can hide foam panels...

Randy, thanks for the clapping tip.

My sofa is only 18 inches from the rear wall and about 12 ft from my speakers. I have two diffusers about 5.5 ft high on either side of the sofa the wall. 

a lot of my issues/uncertainty come from the fact that I want the room to stay aesthetically pleasing. This is why I'm gonna do another diffuser.  I'm also going to do some simple bass traps that I can hide well...
Foam panels are so like 80s. Especially if the foam is anything like Sonex, one of the worst things ever foisted on naive gullible audiophiles. And it seems like such a good idea, you know, with the photos of recording control rooms covered with Sonex. 
Foam panels are so like 80s. Especially if the foam is anything like Sonex, one of the worst things ever foisted on naive gullible audiophiles. And it seems like such a good idea, you know, with the photos of recording control rooms covered with Sonex.

Actually @geoffkait, foam panels can and do work. Even the well respected GIK acoustics acknowledges 4 inches foam equates to 1 inch of their fiberglass (and other materials) paneling. Moreover, many companies that sell foam panels can and do provide third party lab tests, such as

Moreover, foam can be and often is used in anechoic chambers, and can look aesthetically pleasing.
@gdhal is right. It's not that Sonex doesn't do ANYTHING. It's just relatively ineffective compared to the average panel from GIK.

I also have to say, having had a chance to hear rooms heavily treated with ASC products, GIK makes a superior product, for far less cost.


I did not mean to imply that Sonex was ineffective. Nothing like that. Nothing that good. What I meant was that it sounds terrible. Even in very small amounts. It makes the sound all phasey like and wooly, unnatural. Sonex use in recording control rooms completely covering the walls would be a sonic catastrophe, a sound apocalypse, messed up.

GIK superior to ASC Tube Traps? Au contraire!
Masterplan...10' ceilings, OK.  What's the room dimensions?  Couldn't find your pic of the space....having lived in a Victorian with 10' ceilings and a small room with plaster walls to boot, know how it can be an echo chamber.  Now I've got 12' ceilings but not so echo prone...*G*
The first step to problem solution is problem identification ... Can't measure it .. Can't mange it .. purchase a calibrated mic .. good outboard sound card and add REW to your lap top

Get familiar on how to measure your room and what the measurements mean ... then you can correctly and effectively treat the room

Your room behaves in two states .. above and below a transition point referred to as the Schroeder Frequency

Above the room's transition point frequencies act like Rays or Beam of light ... because their wave length's are shorter than the room's dimensions ... they will projecting from the speakers in a straight line until they strike a surface and are reflected ... you must apply traps at the point of contact to reduce the unwanted reflections

Below the room's transition point the wave lengths are to long to fit inside the room's dimension and they Pressurize the room unevenly instead of Beaming ... you must trap those at the points of highest pressurization in the room or in the 4 corners and the mid point of the walls where pressure is highest

There are plenty of traps designed as wall art from GIK and Acoustimate ... the room nee-dent look like House and Gardens meets Hell's kitchen 
@masterplan - another product I have used with great success are the 2' x 4' vinyl faced fiberglass ceiling tiles used in drop ceilings.

I created a 4" thick "brick" (about 6-7 tiles) with the vinyl sides facing out.
I covered the brick with black landscaping felt to prevent  the little glass fibers from falling out.

I placed the brick under the sofa and at the back of chairs (we had hardwood floors) but if you have carpet then they would probably not be required.

You can also use them behind canvas pictures for additional damping effect.

Just use a sharp carpet knife to cut them

I spent a day listening to several rooms at the California Audio Show treated extensively with ASC tube traps.

The more treated, the more suck. Not an innuendo. They literally sucked the midrange out of the room, turned the bass into 1 note, and added treble glare.

I live with GIK, they do no such things.  These CAS rooms were awful.

And, shocked the hell out of me since their peeps are really knowledgeable and of course, the products are so expensive.

I used to think of GIK as the poor person's ASC, but between the improved effectiveness of the soffit traps, and the experience at the show this has utterly changed.



ASC is fine ... when used as directed in a program of regular professional care...

sounds like they weren't done properly - not surprising at an audio show

GIK is helpful over the internet; ASC is, or was, helpful in person

18 inches is not bad, but an absorbing panel right behind your head might be a good idea - you can put acoustical cloth on them so they look like an art print

are the side diffusors as big as a bookcase?

I foget when I bought my cal. mic but they run about $80

pics & dimensions needed

@erik_squires re your show experience with ASC I wonder if this is a case of correlation rather than causation. As I understand it Art makes him a stuff available to those who want to use it at shows, and what I guess happens is that folks with "problems" look to ASC to solve them whereas in fact the real cause of the problems are in the choice of equipment e.g. speakers too big for room, poor orientation etc (e.g. Setting up to give the maximum sweet spot for demo rather than the best sound, amazing how few rooms are set up on long wall orientation for example)

as @randy-11 observes when a room is designed around ASC gear, as any acoustic treatment, it can work very well but it's no panacea
Hi Folkfreak,

Well, it is also possible I was hearing the electronics, but interestingly, I've heard Pass before, and not thrilled, but also didn't cause this problem.

This was the first show I have ever been to so meticulously treated by ASC. And room after room I heard a unique situation. Rather, I've never been to a show where all rooms sounded the same. It was truly odd. An exaggerated treble, along with this weird, 1 note bass. Well treated rooms sound huge, expansive, as if anything can be played.  These rooms, even among hotel rooms, were truly funky to listen to for me.

The correlation I found was : More treatment --> more problems. The most treated rooms, the Von Schweikert, Martin Logan, and a couple of others had the most problems. The Vienna with just two corner tubes sounded among the better situation.


So, if I may add, my working hypothesis was one of two:

1. I was having a stroke.
2. Those tube traps were reflective at the HF, and very absorptive in the midrange.

None of the GIK gear I use has these features. They are pretty much mid to treble, and sometimes also bass absorbers.

I think the ASC tube trap design is a mix no? Partly diffusor/reflector + partly absorptive?

Assuming ASC isn't just a horrible brand, I would then say perhaps the wrong mix of products was employed.
Tube traps are absorptive at low frequencies and mid (500-1k) and can be absorptive or reflective at high depending on how they are oriented. Full specs are here on the latest model

in my experience they work really well in corners to deal with bass modes, and you can then tune HF to taste by orienting them. I'd steer clear of using them at first reflection points for fear of the effects you observed

sounds to me that the exhibitors in question had speakers way too big for the room and were trying to compensate

youre welcome to come visit me system any time to see how ASC products (traps, planks, soffit and wall damp) can work in my smallish room
wait - the showroom was meticulously treated 'BY' ASC?

or with ASC products??

yes, the newer items are hybrid devices, working in 2 different freq. regions - read all about it in ... Master Hndbk..

So my daughter and her husband are moving and I noticed a brand new temperpedic mattress they had in guest room they were getting rid of. I don not like to collect anything. Room treatment has been mentioned a ton of times before and that the room is close to the most important component of a sound system. Makes sense to me. Well I don't know why, but I thought i would take it home and put it behind my listening position. I did that a week ago. 
It made a big difference in the sound. It is way more open sounding. More dynamic. It has a fuller harmonic structure.  It is more real sounding. It is more expressive. I think it is a big improvement. But it has only been a week. 
Just wanted to share. 

@marqmike , did you place your equipment to rest on temporpedic maddress?

I guess that audio components also need some comfortable rest.

@williewonka thanks! I may try that...

@asvjerry I'm in a 117 year old craftsman and I know I can improve a bit

Someone mentioned the foam factory and I think some of their things may work for me.

what a great discussion his formed into!

thanks everyone for all the input!

ASC was at the show so I would assume they helped treat them, but I do not know for sure.

Also, to the OP, contact GIK for advice. Super nice people, great range of affordable products.
The GIK Tri-Trap corner bass traps are very interesting and should be more effective than the customary free standing bass trap panels (should actually trap the undesirable bass frequency backwave).


Correct orientation of tube traps is essential to proper spectral balance.  In my room with my summer setup, the traps on the front wall corners have the dot of the reflective side pointing directly at the listening seat.  The tube traps for the rear wall corners have the dot facing forward and angled in at the intersection to the wall.   I have a mixture of corner tunes and wall mounted bass traps plus absorbing panels.  As with most things, if a small amount is good, a whole lot more is usually not better.


"As with most good things, if a small amount is good, a whole lot more is usually not better."

Amen to that, rhljazz, especially when it comes to absorption.

RE Tube Traps, the funny thing about them is the notion that they are always supposed to be in the room corners. That's simply not true. Just use a test tone and SPL meter and what you'll find is sometimes the standing wave is actually a foot or more away from the corner in one direction or the other. 

True that, Geoff. Experience has taught me that actually trapping the backwave is key regardless of placement.

I treat my room, with cheap panels of different materials, one at a time, with the ears open to listen the results... After a week of this process, the results were great indeed.... No more echoing dead sound, now clear bass, better musical rendering of timbre, better even at nearfield listening position...conclusion: no need to buy expansive products.... I dont need bass traps in corners at all...My room is a square 14 feets with 2 windows...i add a carpet,i treat the windows for vibrations,for the  sound atmosphere i use some tourmaline crystals... Patience+experiments+2 ears  do the job...
I think if people focus on first reflection points with some absorption, then go for bass traps, they can make some big differences in the room and improve sound tremendously.  A dead room is no good as is the reverse, hard reflection surfaces everywhere.  

One small point, getting a room right does not mean the speakers sound good.  Flawed speakers are still flawed.  They may even sound more flawed than before.  (A bass light speaker might not sound bass light in a room with serious low end resonance problems).


You brought up some excellent points. I am a newbie when it comes to room treatments. I have been on fence for while, I guess my biggest dilemma is where do I start.

My room is 30' W x 10' D x 8' H.  As is my room sound pretty good but it's not perfect and may sound better with some room treatments.