Room Treatment

Talk to the folks at GIK Acoustics. They'll advise over the phone. Their wall mounted 244 bass trap panels behind speakers and 242 panels on side walls and on wall behind listening position made a big difference in my room (similar dimensions as yours but more reflective, I'd say). Floor standing soffit bass traps in corners have much less of a noticeable effect though I continue to use them. 244 & 242 panels definitely some of the better money I've spent on audio, in my opinion.

Ghosthouse,

Thanks for the response. I talked to GIK a couple of days ago and they recommended soffit bass traps in the corners. I submit they recommend their most expensive products. I know the ASC 16" round tube traps I tried in the corners had very little effect and now I'm wondering what to do? You have the 244 panels directly behind your speakers?

That's a good sized room; have you tried clapping your hands in the center of the room to hear how "live" it sounds? Does the bass sound tight or is it boomy? You may find that you need some absorption or diffusion panels.

It's good that you've got the speakers away from the walls, but 2 vertical absorption panels behind the spkrs and 2 on side walls would benefit, just as Ghosthouse has suggested.

Yup, Ric...One 244 panel behind each speaker. You can always do just a couple things at a time. I thought those 2 bass trap panels alone gave a big chunk of the improvement I got.

By they way, that's a beautiful finish on your speakers.

As with most people who go down the room treatment road, they neglect the ceiling. Often because there may be lighting that cannot be blocked. However if that is not the case, some treatment can be very effective and not very expensive. I have seen simple 'wave' canopies used to great effect. For some ideas, check out the Armstrong acoustical product site, they give a view of what might be possible. Another treatment approach is the use of grid ceilings with drop in panels of all kinds, wood scatter and slot patterns working the best. Some of the companies that market these are still in business. Last thought, in most new concert halls they have adopted a deflector ceiling approach which really improves the overall acoustics of the hall. So, take a clue from that. 'Tuning' the room will provide endless rewards, more so then changing equipment.

Did you rotate the ASC 16" bass traps? ASC designs them so half is reflective and the other half absorbent. A friend of mine uses them and spins them according to the music he is listening to because they have a huge effect on the sound stage.

Hevac1,

No,I didn't rotate them. Based on the dimensions of my room I was told to place them with the seem facing the corner. My room is L-shaped and I'm trying to figure out if I will benefit from bass traps. What are bass traps designed to accomplish?

Rives Parc. They work much better than any room treatment I've tried. No more room boom.

My room is L-shaped and I'm trying to figure out if I will benefit from bass traps. What are bass traps designed to accomplish?

Simply put, bass traps absorb low frequency sound waves in order to achieve a flat frequency response so the music sounds balanced when it arrives at your listening area (most often using an SPL meter).
That's why I said to listen for a booming bass sound or if the bass in your room sounds tight, (tight is good). A bass trap can absorb these frequencies if too much bass, or bass does not sound well defined.

The sound panels on the walls as suggested will absorb or diffuse standing waves that bounce around the room. Think in terms of a concert hall that has been treated to have an even, well distributed sound.

The simple hand clap test will let you hear if there is any echo in the room. If so, add panels to the walls and many times the ceiling.

Let me echo Polk432. My room is extensively treated with ASC bass traps and diffusion devices. However, after all that there were still two bass modes that the traps couldn't ameliorate. The PARC worked wonders. Not cheap, approx. $3500, but worth it.

I got lucky and found one on the bay for 500.00 9 of 10 condition, and the unit really works. Way better than spending lots on bass traps that don't do as good a job. I was thinking of having my listening room done professionally, but who knows the final outcome. Even if I made a big profit on the parc. I'd never be able to replace it for what I paid. It even has a bypass if you want extra bass for certain music.

Idleally it best to know what the problem is before trying to correct it. You could do find modes based on your dimensions, which shows four coincident modes I believe at 141hz. More accurately, and relatively inexpensively you could do room acoustic measurements with room eq wizard.
Low frequeny pressure is highest at walls and corners, so that is why there was "excess bass". Not a problem unless you listen to music there. A secondary issue to low frequency response is modal decay time, which sounds better if generally shorter and uniform.

I have had a a lot of benefit from placing speakers using the golden ratio. Another technique is to offset speaker and espcially listener placement by a few inches relative to room width.

Higher frequencies are easier and can use simple panels or diffusers at reflection points.