With regard to diffusion vs absorption with GIK panels, it costs only a little more to hedge your bets. I was initially skeptical about diffusion, since I was trying to tame a very bright room. I ordered Alpha panels with the optional cloth finished back so that they can be used for diffusion + some absorption or pure absorption, depending on which side faces into the room. I found that, in my room, the diffusion was noticeably better.
I have a total of nine GIK panels (3 Alphas, 3 non-membrane bass traps, 3 membrane bass traps) and haven’t encountered any QA issues, other than the little adhesive backed GIK labels eventually falling off the cloth covered panels.
I initially sent room measurements taken with a calibrated USB microphone and REW to GIK for recommendations to start off the process.
As expected, the improved reverberation time makes the room act as if it is much larger. Speakers (Sony ES SS-M7) generally considered to need lots of space to work well never sounded better...
I have a total of nine GIK panels (3 Alphas, 3 non-membrane bass traps, 3 membrane bass traps) and haven’t encountered any QA issues, other than the little adhesive backed GIK labels eventually falling off the cloth covered panels.
I initially sent room measurements taken with a calibrated USB microphone and REW to GIK for recommendations to start off the process.
As expected, the improved reverberation time makes the room act as if it is much larger. Speakers (Sony ES SS-M7) generally considered to need lots of space to work well never sounded better...