how much better is 6 sabine as compared to 5?
Ok, here is what a SABIN means. ONE Sabin(Sabine?) is EQUAL to
to a one foot square OPEN window. In other words, one square foot of PERFECT ABSORPTION....the amount of sound, REGARDLESS of frequency, that goes through the window, NEVER to return. This is why ABSORPTION COEFFECIENTS are applied to a sample of material after testing instead of ratings in SABINES, because materials NEVER absorb EQUALLY across the sonic spectrum. Not only that, but because of the WAVELENGTHS of LOW FREQUENCY SOUND, there isn't a TESTING LAB in the world that can measure absorption below 125hz. Thats why all Absorption coeffecients ratings only go down to 100 to 125hz. There is simply no way to measure absorption at frequencys below this threshold. At least from my understanding. There may be a better way to express this, but you should get my drift anyway.
In other words, build panels to straddle the corners if it allows more panels elsewhere. $ and material no object, build the chunks for the corners, as they do perform better for the low freqs.
I totally agree. Thats why I mostly show panels straddleing corners for short term projects like HyPe's, or for people who's budgets are limited...like MINE
Besides, for projects like BOOTHS, there is simply no room, so I suggest lining the complete inside with 2" or 4" thick if you have room, and a layer as deep as you can afford on the ceiling or even straddling the wall/ceiling intersections if you have room. So what if it sounds dead? A booth offers NO acoustic "ambience" whatsoever, and in fact will be the WORST sound you can get without absorption. Well, thats my .02 anyway.
Doesn't seem to be worth the extra cost for super chunks.
My point exactly. Unless you can afford the REST of the chain as well...like mic's, reference monitors, etc etc.
BTW, while we're at it, there is somethine else you might be interested in. Its called the "edge effect". This is a well known phenomena in acoustic circles. The basic idea is this. IF, you have a set amount of absorption material, say a panel 8'x8' feet, you can achieve MORE ABSORPTION in SABINES if you cut this panel into 1' or 2' squares and mount them in a checkerboard or spaced pattern vs using the panel as ONE piece. This is because of DIFFRACTION at the edges. I'm certainly no acoustic scientist, but from my understanding, DIFFRACTION at the edges will contribute to absorption, EVEN THOUGH the material may be rated at a certain ABSORBTION COEFFIECIENT per frequency band. However, even when testing the material, DIFFRACTION occurs, which results in absorption coeffecients GREATER THAN 1...which seems impossible...but....Diffraction is the reason.
Not only that, but when absorption material is mounted on a wall in a "patchwork" pattern, this will "somewhat" contribute to DIFFUSION as well. How much? Who knows. I certainly don't but thats what I understand from reading the Master Handbook of Acoustics.
HENCE, HyPe, the use of "patchwork" at your rear sidewalls. ie...more bang for the buck!
