Short Takes: Echo Busters Room Treatments
Marshall Nack
1 October 2001

Echo BustersSpecifications

DOUBLE BUSTER:
Sacoustic panel providing diffusion and absorption
Size: various models available
Weight and color: various
Price: varies by size and options selected

CORNER BUSTERS: ceiling corner treatment
Price: $120 (set of 4)

Echo Busters
940-D Grand Blvd
Deer Park, NY 11729
Phone:888.ECHO.BUST (888.324.6287)
Web: www.echobusters.com

A Room Is A Room Is A Room?

Room treatment should be very high up on any audiophileís list. Questions on the topic come up regularly. Yet most audiophiles are at a loss on the topic, and even the "experts" flounder on the reefs of room-tuning advice. I stumbled along trying this or that and, quite by accident, I hit upon the following novel solution.

Chapter One Of The Novel

I believe in heavy usage of acoustic treatment, and my room shows it. First reflection areas on the side walls are damped with three-inch-thick absorbent foam panels from Sonex. Three of the room corners have Double Buster (DB) diffusion panels from Echo Busters straddling them catty-corner style. The fourth has the absorbent "Wave Guide" rippled foam product from RPG. The two DBs in the rear corners go all the way up to the ceiling; the single DB in the front reaches to about 6" below the ceiling. In addition, the two front ceiling corners of my room have Corner Busters in the open area above the DB and the Wave Guide stuff. The front and rear walls and the side wall area behind the speakers all have heavy curtains or rugs on them. With this arrangement of acoustic treatments, and especially the elimination of the roomís right angle corners, I have very good imaging and sound stage integrity. Yet the room is not over damped and unnatural sounding. There wasnít much forethought in this arrangement. All of these products had been collected over time from various experiments and were on hand to play with. I tried many configurations before I hit on using the DB to straddle the corners.

Four In A Square Is Better Than Three

Mainly for cosmetic reasons (I got tired of looking at the odd piece of Wave Guide material) I decided to cover the fourth corner with an additional Double Buster. I was caught off guard by the happy result. The addition of a fourth Double Buster had the effect of balancing the acoustic energy in the room. The stage clarified, images locked in place and became stable. My impressions were confirmed when I took out the old Stereophile Test CD I and played track three to check Channel Phasing. The out-of-phase signal was even more vague and hard to locate; the in-phase signal was sharp as a tack. In addition, now I could physically feel the room in better balance. I knew the sound stage had been uneven and weak in the corner covered by the RPG Wave Guide. Iím sure I was mentally compensating for it, but I accepted it as a given in this room Ė one of those problems that you think are beyond an obvious solution. As I said, overall, I had a pretty good stage and there were other areas that needed my attention. That extra mental effort is gone now and the result is I have much higher confidence in my sound. Maybe because these corner-placed DBs throw sound energy back into the room, as opposed to absorbing it (like the Wave Guide stuff), the energy from that fourth corner was necessary to balance and stabilize the diffused sound from the other three. That jives with the change Iím hearing.

I have long suspected the phrase "acoustic science" is an oxymoron. The effective application of room treatment is more like an art form. No one suggested I try the DB catty-cornered. I didnít read about it in any book. I just happened to have most of the products on hand and on a hunch, I went ahead. In the end, there is no substitute for experimentation, and this can be costly. My experience here would suggest that symmetry is very important in room treatment. However, I have also read advice advocating intentional asymmetrical treatment. Whatís an audiophile to do? A good starting point is the recommendations found at the Echo Buster web site.

Double Busters are attractive, cloth-covered, wood-framed panels that you put on the wall at strategic points to control acoustic reflections. They are part of the family of affordable room treatment products available from Echo Busters that have become familiar to so many audiophiles. They come in many different sizes and colors, are about 2" deep, and are of sufficient weight that you need to use nails or the like to mount them on the wall like a picture. I leave them standing on the floor. Sound waves first encounter twin curved surfaces on the Double Buster panel, which serve to scatter and disperse most frequencies. The wavelengths of bass frequencies are too long to be affected by the curved surfaces, and thatís where acoustic foam comes into play. Behind the curved wooden surfaces is absorbent foam, which fills the body of the panel. Thus, the Double Buster serves to diffuse mid and treble frequencies, while providing absorption into the bass range.

Corner Busters, according to the manufacturerís website, "absorb almost all the frequencies that hit upon it and prevent them from being ricocheted back into the room, amplified like a megaphone. The center of the Corner Buster has a reflective section which allows the higher frequencies to retain their sparkle while effectively eliminating mid-range echoes."

Iíve tried products that cost less, but eventually found them lacking and had to be replaced. Of course there are products that cost more. The Echo Buster lineup offers the lowest cost route to effective room treatment.

Further points. I tried hoisting the two front DBs so they touched the ceiling. The sound became dull and lost color. Oddly enough, that gap containing a ceiling Corner Buster is the way to go. Also, keep in mind that after the ceiling corners, the most important area to treat is at the level of your ear.

Iíll have more on fine-tuning the room using the solution above in another short take coming up soon.