Home Tweakers' Asylum

Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Philosophical: The state of room acoustics

Not to start a flamewar, but... :)

After perusing the forums for a while it seem surprising the amount of skepticism about room treatments in the forums, particularly those who feel the affects of room acoustics can be mostly ameliorated by tweaking their electronics and front end gear.

Room acoustics is a pretty established science. It's founded on fairly basic physics, a lot of it is high-school level wave theory.

(Fun pictures from a smart guy)
http://www.gmi.edu/~drussell/Demos.html

How loudspeakers interact with a room is also well understood. Speakers are designed to couple with rooms in various ways, such as tilted bezels to avoid floor reflections to wall-loading for better bass response (my MGMC1's sound awful when they aren't right against the wall, which is what they are designed for.)

(Not as fun pictures and spectrograms)
http://www.livesoundint.com/archives/2002/janfeb/room/room.php

Now, if your room has a resonance at, say, 120Hz, there isn't much you can do about at the front end short of EQ'ing down that band. I'll go out on a limb here and say damping the chasis of your CD player won't EQ out 120Hz, nor fancy AC power cables, nor fancy audio cables unless they are designed poorly and notch out 120Hz for some reason :)

Although the physics behind why sound behaves the way it does is well-understood and founded on basic wave princible, figuring out how to fix a room is another matter. You can't just throw some tube traps and corner traps around, maybe a diffuser or two, and call it done. The right way to do it is mathematically, and unless your major is physics with a minor in vibration and acoustics, you won't be doing it by hand. You're going to need software, and it won't be cheap. RPG makess a decent package for about $100, after that you're talking in the hundreds or thousands of dollars. It will, however, give you a really good idea of how your room acoustically behaves now, and what to do about it's problems.

The less-than-ideal method is trial and error. A SPL meter and frequency sweep CD help out a lot. A computer-based RTA and microphone (I use my Rat-shack SPL meter line output) will help out even more. Ears are about the worst instrument for tuning a room, not because of their design, but because they are connected to a brain. What sounds good now might sound awful tomorrow.

Tweaking room acoustics is tricky, however it is an established science and there is a lot of knowlege on the subject out there. Pick up a book, visit some web sites, and do some research before spending money or time on treatments. A little planning will go a long way.

My setup:
Dell laptop running SIA SmaartLive RTA
Radio Shack SPL meter on a camera tripod used as instrumentation mic
M-Audio Quattro 24/96 USB audio interface


/*Music is subjective. Sound is not.*/


This post is made possible by the generous support of people like you and our sponsors:
  WEET Music Caps  


Topic - Philosophical: The state of room acoustics - jbmcb 05:52:44 12/21/04 (5)


You can not post to an archived thread.