Mike Sorensen (@mikesorensen06) is a master cabinet maker, structural engineer and the author of the AcousticFields.com sound diffusion audio blog. I think you’ll find his research on activated carbon for acoustic absorption very interesting.
If you’re going to make a great recording you have to find a solution to the room acoustics. Like the black sheep of any family, room acoustics are somewhat left un-talked about given their unsexy nature. Yet they are key to helping you produce the best sound from your recordings whether in the live or listening room.
Some people think that throwing up a bit of foam here, dampening the sound there and generally shutting the door and turning off the extractor fan will do it but alas no. There is a big science that goes into it and I want to share some of my years of experience with you today so you can start to consider some of the treatments and how they work in conjunction with your studio space.
Diaphragmatic absorbers are powerful, low frequency, absorbing technologies. One must build a solid, sealed box that has a front wall that can “move” in reaction to sound pressure waves. This front wall movement slows the wave down, so that it can enter the inside of our sealed cabinet. Yes, the cabinet is sealed without any air holes. Low frequency waves that are 40 and 50 feet long do not care about some 1/4″ air holes in any type of absorber. With low frequencies we are dealing with waves of energy not rays.