Another room treatment convert

Newbee,

If you listen to Eric Winer he suggests that virtually all people have bass problems whether they realize it or not. Typically bass traps are best placed in vertical corners or horizontal corners at the ceiling...or the tri-corner at the ceiling. You can 'protect' the mids & highs from being impacted by bass traps by placing a porous, but reflective surface on part or all of the front of the bass trap.

With respect to your last paragraph...I'm not completely sure of what you're trying to say...but my gut says it doesn't 'sound' right...so to speak.

Picked up the mineral wool tonight. Now if the weather will break so I can cut the stuff outside.

Fishboat, I was trying in my last paragraph to address Acoustat6's comment that "all surfaces need treatment". I thought that was an over the top statement.

FWIW, I'll try to explain the basis for my last paragraph. I'm sure you are aware that sound waves from the speakers can reach the listener directly from the speakers and bouncing from the walls on either side of both speakers from both speakers. Without attenuation they will screw up sound quality substantially something we will all agree about. For example the original signal from the right speaker will be direct to the right wall (1st reflection point) and the left wall (2d reflection point). Ditto the left speaker and both side walls. So its no secret that you want to deaden the 1st reflection point, but the 2d reflection point can also be a problem if not treated. In addition to those signals which most folks will treat for, each speaker will be putting out signals which strike other portions of the opposing side walls, bounce off the back wall, back to the side walls and back to the listening position. Untreated the room seems to have become an echo chamber.

Now all you have to do to prevent those signals from bouncing off the side walls is deaden the side walls. If you deaden the side walls you don't need to deaden the wall behind you to eliminate this signal from reaching the back wall and bouncing back to the listening position.

If you treat both walls you will never have any signals bouncing off the side wall reaching the listening position.
Or you can get most of the same effect by simply treating the wall behind the listener position in addition the the 1st and 2d positions on the side walls. (That was the reason for my rejection of the all inclusive statement by Acoustat regarding 'all' surfaces. Perhaps I just took his statement too literally.)

Now all you have to do the reduce wall reflections to an appropriate level is determine what density of materiel you need to kill/reduce those frequencies that are bothersome.

I'm not at all sure that I have effectively communicated my thoughts on this, but if I've still not cleared up for you what I meant in my post to Acoustat6, sit down with some paper and reduce this all to geometry, it might make more sense this way. I realize its not that simple but it illustrates the fundamentals regarding bouncing sound waves.

Hope that helps, if not I had fun trying to focus my fragile mind. :-)

Newbee,
Can't disagree with the second explanation. The first go 'round sounded to me like you'd treat the right side wall(reflections..), but not the left..etc. That would be a little twisted..so to speak.

The partial treatment approach may fail when it comes to ceilings & a carpeted floor as the carpet won't help the first reflections there.

In the end, treatment is all relative to the listening position...whatever makes sense.

Hi newbee and fishboat, Dont worry my mind is fragile also, too much information running through my brain....

Yes you took me too literally when I said "ALL surfaces" I did not mean every square inch, but the six boundries. Though in a zen sense every surface is "treated" already, with carpet, tile, plaster walls, windows and curtains etc.. Now the question is, are these usual sufraces which we choose to put in a room, are these the surfaces we want for good acoustics? Yes too much carpet is bad just as too much ceramic tile is bad. Too much plaster is bad just as too many windows are bad etc, etc. Now that being said and I am sure agreed upon we can discuss how much and what type of acoustic treatment we want. This is dependant on several factors. The room and its current acoustics, the sound system, its owners sonic goals and "the decorator". Couches, people (even if it is only myself, remember I am one of the dreaded single chair Barn Boyz, actually I do have two chairs but the other is reserved for my dog), rugs, tiles and plastic ficus trees all have an affect on the room, but how much and what can these item do? My favorites candles, incense, a lava lamp, records, motorcycles, books and bongs, all have a sonic impact on the room. My room still benifits from bass traps, absorption and diffusion, and yes I feel this was a turning point in hi-fidelity for me.

Its just a balance with everyday items, bass traps and whatever else floats your boat for diffusion and absorption . Who has a decorator anyway :) ? Barring decorators for the moment, all rooms have bass problems and the better they are addresed the happier you will be. Then its a walk in the park for the high freq, all you have to do is mount your sectional couch on the ceiling and.....:)
Bob

Thanks for the link about the superchunks. Somebody mentioned these before and I misunderstood the concept. Looks like a good, practical, broadband design. Might not absorb low enough for room standing waves, which are typically 30-90 Hz and nearly impossible to deal with, but probably some of the harmonics.