Acoustical Foam

Firecracker,

If you check out my virtual system you can see how the new GIK Tri-traps integrate into a room in an aesthetic way. These use heavy mineral wool and are broadband absorbers (effective down to 100Hz with a tiny little bit of absorption even at 50 Hz).

As long as you have something broadly absorptive and with a density of 3 pounds per cubic foot or more (foam, fibreglass, mineral wool) then you can get some nice results with decent coverage. I believe that controlling rear wall (behind your listening position) reverberation is the most important use of these products.

As others have stated above a reflective room is pleasant and a dead room is dull and lifeless....which suggests that one should avoid heavy acoustic treatement in front of the listener.

Behind the listener is another matter.....anything reflecting from behind you is likely to interfere with your enjoyment, hiding detail and crowding the sound field in a claustrophobic manner. You will notice I use a combination of dedicated professional acoustic treatments, bookshelves, furniture and a massive stacked log fireplace...all designed to broadly absorb and improve the reverberation decay times. Long reverberation times are reduced dramatically whilst secondary reflections from side walls and ceiling still give a lively feel to the music. Dead sound is NOT the goal (in fact the early reflections help bring out more detail in music.....long reverberations are, however, a nusiance)

First-reflection points (side, ceiling, floor) need first attention and, then, depending on the room, system and furniture, you may need additional treatment. However, what is almost always needed is broadband bass trapping and foam tiles will do NOTHING for that.

You should look at sites like www.riveaudio.com for links to reliable recommendations.

Kal

Firecracker,

BTW - 4" tiles are no good for broadband absorption....you need greater thickness.... a minimum of 8" with foam - the most effective treatment location being the corners. Tiles may actually be counterproductive as you attenuate the upper mids and make the lower mid & bass relatively worse...i.e both a dead and a boomy room.....YUK.

one can't generalize about sonic preferences. a dull room with attenuation in the treble may be preferred by some and not by others.

this issue has nothing to do with accuracy or "hi fidelity".

it is all about achieving one's sonic objectives, whatever they are.

i use foam on the side walls and behind the listening position, a room tune in the center between the speakers and a room tune in the corner.

i tune the room to create the "sound" i enjoy. it's all about experimentation. it doesn't hurt to use a spectral analyzer at the listening position.

Interesting responses full of great information. I have put the foam on the walls immediately flanking and the wall behind my speakers and equipment. I have not treated the back wall where my chair will be located. From what I've read in this post, that is the opposite of what should be done, but at this point, I'm going to foam all the walls and then reverse tweak the room by removing foam until the desired goal is reached. For low frequency control, I have positioned 24"X10"X10" wedge shaped foam which joins at the junction of the ceiling and the walls. It is probably 6" thick at its greatest depth. I'm moving my equipment over tomorrow with the exception of my amp, speakers, and sub which are too bulky and heavy to move in our cars. I'm disassembling my MapleShade rack tonight. It weighs rougly 200 pounds assembled and is great to look at but is difficult to take apart and move when required. I will follow-up to this post once everything is going in that room. It is an experiment I'm looking forward to sharing here as the observations may be useful to someone else venturing down the path of room treatments which may not be as well understood as some more well known topics such as the differences between cd and vinly or the pros and cons of tube vs solid state amplification.