Axiom Home Page Forums General Discussion Advice from Axiom Owners Acoustic Panels

>>Now, how do I graph the room again?

Personally, I would PM either Randy or Mark and say "so, like, wanna come over and listen to my system ?"

Iowa <-> New Hampshire -----> Florida? I dunno John, I just don't know ... I'll give it a try though.

D'oh !!

Um... (thinks for a minute) well, duh, obviously I meant invite them in the winter when it's bitterly cold in both places and Florida doesn't seem so far away. Yeah, that's what I meant !!

It's not too bad, really, although it is kind of mind-numbing (although not as bad as archaeology). You can download a series of test tones from RealTraps and burn them onto a CD so that hitting "next" moves to the next frequency. Then you just set up the SPL meter on a tripod in a reasonably readable position, step through the frequencies on the CD, and record the SPL meter reading at each step being careful to stand in exactly the same place every time so as not to muck up the readings. It's easier if you have a "reader" and a "writer-downer".

Here are the instructions from the Rives CD :

http://www.rivesaudio.com/files/TestCDinst.pdf

The other option, also from Rives I think, is a little kit you hook up to a PC your HT aux inputs. You push a key, it makes some wierd noises, digests the results for a minute, then spews out not only frequency response charts but spectral decay graphs for all the frequencies, eg "the room is too absorbent at most frequencies but has an evil echo at 500 Hz".

http://www.rivesaudio.com/software/testkit.html

For the HT owner who has everything -- including crappy acoustics

Rick, that is great, I'm trying to decide what to do...the tri-traps are more expensive, but seem to have much better absorption compared to traps that span corners. Everything is better than foam, based on my recent studies. If the trap is made from rigid fiberglass like owens corning 703, or using mineral wool board (cheaper) your good to go. The 440 and 442 (1st/2nd reflections) are much much cheaper.

I've learned tons from the Realtraps website. The videos showing how nulls can exist within 1" is amazing. Ethan's HT room is killer with 39 traps. I've also learned that what people say about HT being differant than music for treatments is not true, the main goal is to achieve a flat as possible frequency curve. Reducing ringing, combing is also very important. You can't do that with just furniture, drapes, etc...

I'm also tossing around the idea of building my own. It might be cheaper than building them. Insulationworld.com has good prices on Owens Corning Mineral Wool board.

That would be great to see your before and after results. Thanks for your help via PM's, I'm excited to start my own DIY traps.

I found a local insulation supplier in my home town that had the OC703 for about $9 sheet, pretty cheap compared to the online sellers and that there is no shipping charges. I purchased enough to start with 2 8ft SuperChunk Bass Traps for my front wall. Royce, thanks for the Bryan's referrel at SensibleSound. Him and I talked for about an hour today and he was very helpful and knowledgable on this subject. If only I could have the knowledge that Bryan or Ethan Winer have in this area, it would be scarry.

>>If only I could have the knowledge that Bryan or Ethan Winer have in this area, it would be scary

I ran across a quote a while ago talking about how to make one of those wonderfully green English lawns...

"start with any green space, then seed it and roll it for 150 years..."

I think it's the same with acoustics. These guys have spent 20+ years implementing room improvements then trying to figure out why the heck "it didn't work like it was supposed to...". The rest of us just try to understand and apply their comments and advice to our environments.

Just think about that scene from "silence of the lambs" where the victim is fumbling around in pitch blackness and the bad guy has night vision goggles.

We are the victim ;(

Very well put John, I'm sure you have read this article by Ethan from RealTraps, but I'll post it for the others, basically an Acoustic Treatment 101. Yes everyone, acoustic treatments are not just for music/recording studios, the same rules apply to a HT environment.

http://www.ethanwiner.com/acoustics.html

Getting up early to start building my superchunk bass traps, keep ya all posted. We've had really humid temps lately so want to get done early so I don't sweat to much.