I was so excited to see a little bit of pro audio creeping into the eevblog, but DIY acoustics! I could not believe it!! I am a young guy building a career as an EE specializing in pro audio. Specifically I do custom and repair work for recording studios, servicing all kinds of gear old and new. I really enjoy your work on eevblog and the amp hour, and am regularly listening while elbow deep in someone else's audio toys. My master work so far is a studio here in Brooklyn, NY that I, and the original owner built together. Take a look here:
http://www.3eggstudios.com/ Anyway... back on topic. The Acoustisorb 3 material looks very interesting. Having always worked with mineral based fiber insulations (to achieve the necessary MTC ratings and low freq absorption) I am all too familiar with the hazards of these products. The itching!! The Tontine data sheets look very promising, so I will be looking for some bonded polyester manufacturers state side. You can absolutely hear a change in that room on the camera audio; In fact better than your large diaphragm condenser mic, because of the difference in distance, gain levels, and polar pattern. What I am really working towards is this: You can improve the performance of your panels even further with a few simple mods. One of the first things is to displace the panels or "traps" from the wall a few centimeters. You can do some math to calculate the distance to correspond with a particular room mode, however without a time-energy-frequency analysis of the room, that is a bit impractical. Around 4-5cm should be appropriate. With that in mind, the next mod would be to remove the rigid backing and replace it with either a perforated backing material, open back, or additional fabric. This is to allow absorption from both sides of the Acoustisorb 3 material, as well as allow the material to relax. With a semi-rigid fiber insulation compression will change the absorption coefficient and could negatively affect the materials performance. Take that last one with a grain of salt, as I said before, the polyester stuff is new to me. Anyway... congratulations of taking the most important (an most overlooked) step to creating/improving your home studio. Everybody just wants to buy toys, not build better rooms. Keep up the good work Dave!
-JR