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Ethan Winer · 18th February 2005

Stein,

> how much of the room should be absorbtion and how much diffusion. <

Angelo's advice from Bruce is right on, though that pertains more to picking good room dimensions and shape, rather than what percent absorption you asked about.

One very rough guideline is to treat about 30 percent of all the surfaces combined. Here's how I approach this:

Start by treating as many corners as possible with bass traps. Some bass traps also absorb mid and high frequencies, so that might or might not add to the 30 percent total.

Next is to treat the first reflection points on the side walls and ceiling with absorption. Placement for those panels is very specific, and is generally a small part of the total.

Next is to consider all parallel opposing surfaces. If the floor and ceiling are both reflective, you'll definitely need to treat the ceiling. A lot of studio designers use a cloud that covers much of the ceiling, but leaves a small (2 to 3 feet) border around the edges reflective.

> My thoughts were to deaden the back wall completely, deaden around the front windows and alternating strips of live, soft on the side walls. <

I like stripes, and a checkerboard pattern is good too. I don't think you need to deaden the entire front or back wall. The back wall could be treated just around the center portion. The front can be treated more to the outside, closer to the speakers.

As for diffusion, good diffusors are useful, but the cheap ones I've heard sound worse than a bare wall. Further, your room is a bit small for diffusion. I'd start with absorption and then consider adding diffusion later only if you're still not satisfied.

--Ethan

18th February 2005	#2
Ethan Winer Gear Guru Joined: Oct 2002 Location: New Milford, CT, USA Posts: 12,331	Re: How much Absorbtion? Stein, > how much of the room should be absorbtion and how much diffusion. < Angelo's advice from Bruce is right on, though that pertains more to picking good room dimensions and shape, rather than what percent absorption you asked about. One very rough guideline is to treat about 30 percent of all the surfaces combined. Here's how I approach this: Start by treating as many corners as possible with bass traps. Some bass traps also absorb mid and high frequencies, so that might or might not add to the 30 percent total. Next is to treat the first reflection points on the side walls and ceiling with absorption. Placement for those panels is very specific, and is generally a small part of the total. Next is to consider all parallel opposing surfaces. If the floor and ceiling are both reflective, you'll definitely need to treat the ceiling. A lot of studio designers use a cloud that covers much of the ceiling, but leaves a small (2 to 3 feet) border around the edges reflective. > My thoughts were to deaden the back wall completely, deaden around the front windows and alternating strips of live, soft on the side walls. < I like stripes, and a checkerboard pattern is good too. I don't think you need to deaden the entire front or back wall. The back wall could be treated just around the center portion. The front can be treated more to the outside, closer to the speakers. As for diffusion, good diffusors are useful, but the cheap ones I've heard sound worse than a bare wall. Further, your room is a bit small for diffusion. I'd start with absorption and then consider adding diffusion later only if you're still not satisfied. --Ethan __________________ Ethan's audio book is now available!