[Puma Cat]

Originally Posted by Soundmig

As Stephen (Puma Cat) says, the mirror method works really well and will give you the locations that "must be" treated. Most acoustics guru's also say that you can add too much absorption, but you can't add in too much diffusion, so if you have any "budget" left over - add some diffusors. Diffusion instead of absorption behind the speakers (front wall) is generally a good idea, and diffusion at other points around the room can be helpful as well. I see that Stephen is using diffusion enhanced absorption devices - good call!!!! If budget becomes an issue I've found that hitting the ceiling and back wall reflection points with inexpensive high density polyester absorption panels (cheap at amazon.com) are surprisingly effective and can be attached using those removable 3M mounting strips. Those can also be cut in half (at a 45 degree angle) to make triangles that can be mounted as "flags" to the wall/ceiling interface which cuts down on flutter and "splash".

Great info!

Yes, the GIK Alpha 4A panels work really, really well. The 1-dimensional pattern of slots in these cause a mathematically random scattering of sound waves and really improve the sound quality. And, I would agree that you can't have too much. This is exactly what James at GIK told me as well, and when I bring in additional panels from the spare bedroom and set them up, each one makes the presentation better. The only issue I'm having right now is I've got pretty much all the easy places to place these already occupied with these. There is another place in the room where it would be beneficial to place one of these at 1st reflection point on the right side, but presently it means I have temporarily place a small Ikea end table there and then put the 4A panel on it, as it is too thick to mount permanently to the wall in this position. I'll probably order some 2" thick 24" x 24" panels and mount one there, and put the other along the remainder of the big picture window along the left side of room, behind the couch.

In my case, I don't really need to worry about the rear wall because my listening space opens to a 40' long hallway down to my master bedroom. So, I don't have much of an issue with reflection off the back wall causing peaks or nulls in the room modes.

All told, I am very impressed how well these GIK 4A diffusors work! You can immediately hear the positive improvement they bring.