Acoustic TReatments - What, How much, & Where?

As the search continues for me, I ran across some items Ethan winer had drawn up about acoustics and DIY stuff. Probably as frankly put and simple as one could ask for... and some items from Sound on Sound magazine. Both point towards 'studio' applications, however I see much of the info applicable to residential use.

As freehand cutting, say with a skill saw, is just not a good idea for me, I'd like to ask if anyone has found or fabricated diffusers that work, without the need for slicing and dicing curved woods..... naturally, the more affordable the better.

And, has anyone found a resource that will allow one to buy the merchandise (room treatments), try them... and if not satisfied, return them... I'm having little luck there.... a couple have said they'll take back their 'standard' stuff.. Fine. As it should be. but there have been ony a couple. most say "it's your's."... no returns.

Psychicanimal
Thanks. A lot. I do appriciate the thoughts. though my issues are a bit different than what you may have gleaned from my posts... my room is rectangular. 13.5 x 19.75 with openings to either side, though not across from each other and the openings are several feet past the driver of the loudspeakers. I found some 'ratios' for room sizing using the height as the baseline... and given one of those ratios, (there are three), my room comes out as close to great as should be super for listening. the openings which are about to be closed off as sooon as I can decide on the doors to be used, will be of immense help. I'm sure. I have one other door in the room that needs reversing so as to lessen the 'pocket' it creates as is. it's at the first point of reflection of the right speaker. it'll still be there... but only an inch or so, two, at worst.

Newbee
I did read your posts as you mentioned previously. Funny, I was unable to find the threads doing the search thing... I had to look through the posts for each member to find it. it corresponds to much of what Ethan W. had written. Thanks.

have you found any items other than bookcases that can be used as diffusers behind the speakers? A friend says use the "Skyline" from RPG... Know of a suitable replacement with a smaller price tag?
many thanks.

There is a thread somewhere here that describes the DIY version of the Sylines. It's simple but tedious.

Blindjim, Re diffusing materiels for use behind your speakers.

Assuming we are talking about high frequencies, and assuming that your talking about diffusing sounds directly radiating from the speakers, plants (live or artificial) can work well. I've used big Boston Ferns, medium sized dense palms, and weeping figs quite effectively for electrostats and boxes. Personally, I don't care for the 'audio room' look so many prefer, and even without book cases I would (and do) place strategically located wall mounted shelves with typical domestic garbage, books, CD's, Lp's, lamps/tables etc.

As Psychicanimal suggests, if you're crafty at all, it would be fairly simple to replicate the Skylines. All you need is some 1 1/2" square pine boards, a small table saw (easier to do cuts) some wood glue and clamps, paint, and patience. A friend of mine has done this several times very effectively. Your really don't have to be very scientific about it to get excellent results but it helps if you have the dimensional variations used in the Skylines. You could also do it with foam of some type as that could act as an absorber for the higher frequencies and diffusor for the lower (not LOW) frequencies, but I think foam would be tough to work with.

If you talking about a whole, or major part, of a back wall, because of bouncing reflections from other wall surfaces, I wouldn't go the dispersion route.

I'm sure its occurred to you already, but, FWIW, the further you can bring your speakers out into the room the less you need to be concerned with the need to diffuse or deaden the sound radiating directly from the speakers, and unless it is a hard surface such as glass, in the typical room after you hit the 6ft mark its probably of little consequence because there is sufficient time differential between the inital signal and the reflected sound (doesn't necessarily apply to bipoles, panels, or electrostats). I've heard speakers set up in front of an untreated glass that sounded excellent, with only one caveat to bear in mind. The other three walls had differing wall surfaces and were not uniformly reflective which eliminated 2d and 3d relect points so there were no strong high frequencies bouncing about the room.

Interesting stuff. Have fun, but don't get too anal - it will be very frustrating if you do! :-)

Wander around the acoustics forum as they have some good designs that are easy to make.

http://forums.studiotips.com/viewtopic.php?t=535

Search "studiotips and "superchunk" on google & you'll pick up some useful hits.

This link is a mother load of info on the topic:

http://www.bobgolds.com/AbsorptionCoefficients.htm

Also you might go to the auralex site and send in a request for a room treatment design (it's free). You can get an idea how they'd treat your room...it'll be pretty much what one would expect after you read everything you've mentioned(ethan's white paper) & my links here. You'll treat the corners (all 4) for bass, then the first reflection points on the walls & ceiling...etc..

I second Newbee's last comments - furniture, plants, bookshelves, absoption behind the listening position, diffusers on side walls and moving speakers far away from rear wall and keeping listening position around 40% from the wall behind your listening position are all good suggestions (don't sit bang in the middle of the room).

I built a log fire place as an LF sound absorber/bass trap on the rear wall ....of course this is hardly as effective as the real thing (large GIK, Realtraps or other forms of large surface area thick panels) but aesthetically it is so much more acceptable.