Acoustic TReatments - What, How much, & Where?

Hello all you room treatmentfiles.

Being at the point where I probably should have begun, now, I want to 'treat' the room, acoustically. Economic reasons say I might have to go by way of ‘foam’ stick ups on the wall, but I’d really rather not. The desired alternative, however, is panels, and they are mighty pricey. OK.

Reading over the online info at various panel makers websites, (ASC, RPG, GIK, etc), some panels have different ranges of absorbtion, reflection, etc. according to the makers.

Q: How do you know just the amount of absorbtion, or diffusion to incorporate into the room via panels, traps, etc.?

Is there some Rosetta stone that will decrypt this for me… or is it all “trial & ear-ror”?

GIK panels seem the most feasible cost alternative, presently.

Any suggestions or related experiences in regard to sources for, or treatments of, will be more than a welcome thing.

Thank you
I wrote a post for the Rives forum this morning--and the server lost it--along w/ my stream of thought!!!

Rives, the Marantz Esotec Ma-5 class A monoblocks are keepers. The Ma-5's have the magic holographic, harmonic presentation & decay of tubes with the beef, bass control and neutrality of tone solid state is characteristic for. Since in this setup I'm so close to the speakers the SPL produced by the little 30W monoblocks is adequate. My Forté 4 is not getting modded. Will keep you posted.

Weimboy, an open space can be successfully handled by Helmholz resonators. Member Jahaira built three of them and uses them in his house, where his listening space is open to the dining room. The ideal locations might take a while to discover. He said he'll bring them to my new setup; I expect them to deal with lateral diffusion. You ought to check them out.

Tbooe, I find Eight Nerve stuff too expensive & ugly. Slap echo can be handled by Golden Sound Acoustic Discs, and that's what I use.

Weim_boy and Blindjim, You can overcome a lot of the effect of the hard wall on the side of one speaker by simply toeing in your speakers til the axis of the speaker crosses at your hear or in front of you. Removes most of the side wall reflection issues, increases center focus, and makes a much wider usable stereo spread. Looks odd but works for most box speakers. Try it.

In treating your room, don't forget that you can use wall hangings, book cases, drapes hung over walls as if they were covering a picture window,etc. It doesn't have to be expensive audio product to get the job done.

If your going to go with the audio stuff before you buy make sure its purpose fits your needs, otherwise you will be wasting your money.
Hey guys/gals, Rives,
thanks for your comments/input.

Last night I did a few things to my room which made a noteable improvement.

First I moved the speakers further into the room, further apart and toed them in a bit.

Then I covered my Billy bags 500 cd rack with a comforter (this sits on a record cabinet on the back wall - the rest of the back wall is the stereo rack & tall record cabinets)

Next I got rid of the kithen - I moved the VPU 16.5 record cleaner in and voila - a vinyl maintainance room

Next opened the windows doors on the wall opposing the vinyl maintainance room.

This week end I'm planning to float some shakti stones on maple platforms in the pacific ocean which is in sight ~ 2 miles away - I'm hoping that this will be the glue that binds the sound stage together.


Newbee, i am no expert but i thought toe in reduces the soundstage width? In my room, as I decreased toe in I found the soundstage to increase width wise tremendously. Am i missing something.
Tbooze, With box speakers used in a stereo configuration there are two types of sound you will hear when seated in the sweet spot (especially). The first will be the sound which is phase correct, the 'stereo' sound and that will appear exactly withing the confines of the space between your speakers on the same plane as your speakers (in phase stereo sounds can appear to come from outside your speakers but this sound will be behind your speakers, not on the same place, and if you drew a straigt line from your head thru the speaker to the wall behide it it would still be on the inside of the line.

Then there is out of phase information. That is sound which occurs outside of the inner boundies of your speakers. It is most often caused by reflections off walls, ceilings, floors, etc. These out of phase signals can sound pleasant and seem to give you a wider soundstage, but on close analysis they detract from the sharpness of the focus of the stereo sound between the speakers.

In an unbalanced set up, one speaker near a wall and one speaker near an open space the reflections off the wall can not only diffuse the 'stereo' image between the speakers, but it can also cause image shift where in the center image, say from a centered voice, will shift toward the side with the wall.

JFYI, recordings often contain both in phase and out of phase signals. These too will effect the sense of width of your sound stage - but thats a different issue, they should.

For set up purposes there are test disc's which can help you locate problems caused by room reflections. For example, using one I once discovered a set up where when they played an out of phase voice the voice in a very diffused sound appeared on the left wall immediately in front of the left speaker which was close to the wall. The voice should have been, optimally, heard as "coming from all about your room" but as a minimum having no focus. I was able to eliminate that out of phase sounds'location on that wall by using substantial toe in.

If not having sharp center focus (on a sharp center focused signal) which is IMHO essential to getting the best soundstage depth obtainable because you need absolute clarity in the signal to get this effect, then its no problem. Lots and lots of folks love the sense of width they get and are happy with the compromised depth of image, and are really not concerned with getting the best sharpest'stereo' soundstaging available.

FWIW, since some folks forget what 'stereo' sound is all about, in its simplist application you have two microphones placed in front of a group of performers. One on the left side and one on the right side. A performer on the left sides signal will be picked up by both mic's but for the one on the left side the signal will be much stronger and on the right side much weaker. In a well set up system you will be able to exactly locate the position of the performer. A performer standing in the middle will be heard equally by both mic's and as a result you'll get equal signals from your speakers which will cause them to be heard as one speaker exactly in the center. There are no provision in the 'stereo' concept for 'stereo' signals to be heard outside the boundries of the speakers - out of phase, yes, but not 'stereo'.

Hope that helps to answer your question.........