Hi, anybody have any ideas on how to treat a square room (11x11)aprox with room treatments? I've attached a diagram of the room for reference. Problems I have so far are bass nulls in certain frequencies..but overall I just want better smoother sound and wider soundstage, I have a big curtain on the sliding glass door and also behind the seating position covering the closet, don't know if that helps..,...thanks!

Room treatment is a deep subject, and a complete answer requires far more than will fit into a single reply here. So here's the short version which will get you 99 percent of the way there. All rooms need:

* Broadband (not tuned) bass traps straddling as many corners as you can manage, including the wall-ceiling corners. More bass traps on the rear wall behind helps even further. You simply cannot have too much bass trapping. Real bass trapping, that is - thin foam and thin fiberglass don't work to a low enough frequency.

* Mid/high frequency absorption at the first reflection points on the side walls and ceiling.

* Some additional amount of mid/high absorption and/or diffusion on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. Diffusion on the rear wall behind you is also useful in larger rooms.

For the complete story see my Acoustics FAQ. (http://www.ethanwiner.com/acoustics.html)

There's a lot of additional non-sales technical information on my company's web site (http://www.realtraps.com) - articles, videos, test tones and other downloads, and much more.

--Ethan

Note, also, that your room will probably suffer less than a similarly-dimensioned room with solid walls. Those large expanses if glass on the two walls are pretty transparent to low bass and will ameliorate the cumulative effects of the square dimensions.

Of course, Ethan's guidelines still apply.

For å listening room, absorbing the side-walls might not be the best choice, especially not if you want a wider sound-stage. Research seem to imply that side-wall reflection is good for this, and often gives more pleasing results than attenution. However one should be weary of flutter-echoes, a diffusor might be good too have. And absorbing the front and back wall is also often helpful.

AtW

For å listening room, absorbing the side-walls might not be the best choice, especially not if you want a wider sound-stage.

It depends on the size of the room. In smaller rooms, the sound will be larger and wider with absorption at the reflection points. This is because reflections from nearby walls impart the small size of the room onto everything you hear. Same for diffusion at the side-wall reflection points in a smaller room. It makes the sound smaller and narrower than absorption does. Try it for yourself in a room less than, say, 20 feet wide. You'll see. :D

--Ethan

So my problem is bass stronger in parts of the room than others, so I plan on putting traps on the bottom right corner (relative to the picture in OP) do 2x4 bass traps have to go from ceiling to the floor?

do 2x4 bass traps have to go from ceiling to the floor?

The more total corner surface you treat, the better. Always. I have 49 panels in my 25 by 16 foot living room, most of them bass traps. You don't need that many traps for good results! But it drives home the point that more is better.

--Ethan

What if I put a sub in a corner, do I have to put bass traps "ON TOP" of the sub?

What if I put a sub in a corner, do I have to put bass traps "ON TOP" of the sub?
Well, i'd avoid putting a sub in a corner all together. Generally you only do that if you're wanting to boost spl output, but for linearity and sound quality that is usually the worst position for a sub.

ok, i'm going to try some experimenting tonight with some subwoofer placement and see what happens, also another questions, my surrounds are dipole (Paradigm ADP190) how do we go abouts treating 'around' them?

So i moved the sub to diffeent areas and finalized it out of the corner and more towards the middle of the wall (1/3) but I still get a nasty null in bass where i put the small circle on the sofa, sitting in that posiition it sounds like I only hear the bass from the side walls echoing off the corner (ringing?)...wierd? any ideas? The small circle represnts the null the large one represents where bass is the strongest. I still haven't put in bass traps yet, but the angles are where I plan to put them. Will this help?

So i moved the sub to diffeent areas and finalized it out of the corner and more towards the middle of the wall (1/3) but I still get a nasty null in bass where i put the small circle on the sofa, sitting in that posiition it sounds like I only hear the bass from the side walls echoing off the corner (ringing?)...wierd? any ideas? The small circle represnts the null the large one represents where bass is the strongest. I still haven't put in bass traps yet, but the angles are where I plan to put them. Will this help?
In absence of an rta setup i'd use the crawl method. If you can, place the sub in your location and move about your room at the same height as your speaker. How the sub sounds at a certain location when its in your seating position is how it will sound when the two are reversed. This allows you to find the best sub placement while avoiding nulls. I'd use a repeating sub sweep as the test signal when you do this to now only find the location with no nulls but with the most audible smoothest range.

In absence of an rta setup i'd use the crawl method. If you can, place the sub in your location and move about your room at the same height as your speaker. How the sub sounds at a certain location when its in your seating position is how it will sound when the two are reversed. This allows you to find the best sub placement while avoiding nulls. I'd use a repeating sub sweep as the test signal when you do this to now only find the location with no nulls but with the most audible smoothest range.

sub on the ground? port facing forward or backward?

sub on the ground? port facing forward or backward?
Place the sub in your seat and move about. Have the port facing the same direction it would be as if it were on the ground. If it is front firing, have it face you as your crawl around.

What if I put a sub in a corner, do I have to put bass traps "ON TOP" of the sub?

I have my big SVS sub in the front-left corner, with a MondoTrap on top of that. So a trap over a sub is fine. But you can experiment with different sub locations. The best way to do this is to measure the LF response and ringing at high resolution using suitable software like REW, then see what happens as you move the sub.

Also, one big problem I see in your drawing is it looks like you're sitting right in front of a reflecting wall. If so, you'll do well to put some absorber panels on that wall directly behind your head.

--Ethan

I have my big SVS sub in the front-left corner, with a MondoTrap on top of that. So a trap over a sub is fine. But you can experiment with different sub locations. The best way to do this is to measure the LF response and ringing at high resolution using suitable software like REW, then see what happens as you move the sub.

Also, one big problem I see in your drawing is it looks like you're sitting right in front of a reflecting wall. If so, you'll do well to put some absorber panels on that wall directly behind your head.

--Ethan

Actually its a closet behind me with drapes covering most of the opening (projector in closet) would the drapes suffice? Also, if I get the LENRD type traps from Aurelex do I have to cover all the tri corners? or is a one to a couple enough?

would the drapes suffice?

No, unless the closest is stuffed with clothes or other absorbing materials.

if I get the LENRD type traps from Aurelex do I have to cover all the tri corners? or is a one to a couple enough?

Those are not really bass traps because they're too small to target low frequencies. With bass traps, you can never have too many, nor can they ever be too large or thick.

--Ethan

Actually its a closet behind me with drapes covering most of the opening (projector in closet) would the drapes suffice? Also, if I get the LENRD type traps from Aurelex do I have to cover all the tri corners? or is a one to a couple enough?
As Ethan said, the straight LENRD may not be big enough. If you want Auralex, go with the MegaLENRDs. They are great performers:

http://forum.studiotips.com/viewtopic.php?f=8&t=536
http://forum.studiotips.com/download/file.php?id=5191

- Terry

In a sqare room, you're going to have obvious overlap with the modal frequencies. This may require additional targeted bass control in places other than corners to try to minimize this overlap. Things like treating the wall behind you if possible can yield excellent results.

Bryan