Axiom Home Page Forums General Discussion Technical Questions My room's frequency response graph

Hmmm, a few inches of fuzzy stuff? Would a cat work? (I am just kidding) But that idea would probably go over almost as well as asking if I can tack up some sheepskins or something. Oh well.

I'll play with a few things this weekend, and see if anything else helps. If I can direct that null to another part of the room, that might suffice.

And thanks again for your assistance.
Rich

Here's some interesting reading :

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

Owens-Corning 703 rigid fiberglass seems to be pretty absorbent at 250 Hz; might be the best option. Comes in 2'x4' panels, 1" thick...

John, there seems to be a break in the action at the moment, so I'll again raise a point about room size and power requirements. There seems to be an exaggerated concern about "filling the room" whenever it's bigger than average, and thoughts go to 500 watt amps. Room size and listener distance are certainly both factors, but sometimes the inverse square law is misapplied and a 6dB drop per doubling of distance is applied as if it was the only determinant. As has been pointed out before, the reverberent field becomes equal to the direct sound field at a relatively short distance(3-4')in typical-sized listening rooms(see the discussion and especially fig. 10.4.1 here , with the result that the drop in total sound pressure level with distance is far less than the 6dB per doubling figure. Linkwitz also has a very interesting discussion on room acoustics (especially scroll down to reverberation distance and amplifier power sections)which indicates why, as a practical matter, the more ordinary power levels that we use are fine for doing the job.

JohnK & Bridgman--

How about the almost as large dip at 2.5Khz? Is that because it is a multiple of the 250Hz drop? But wouldn't I then expect to see drops @ 500Hz, 750Hz, and at lesser & lesser impacts as I get further away from the fundamental wave?

Doing the math at that frequency (1130ft / 2500) says the wave is ~.45 ft, or around 5.5 inches. So am I looking at multiples of the 1/2 or 1/4 of that? And since I'm right around crossover point (I think! I'm working from memory) it could be either tweeter or woofer, right? (Though the centers of both are aligned).

Any additional insights (& predictions! ) would again be appreciated.

Thanks,
Rich

That http://www.ethanwiner.com/acoustics.html link is awesome!

Thanks.

Rich

Good to see you are reading up. Here are several more for you to review with lots of info on DIY treatments .

http://www.audioholics.com/techtips/roomacoustics/roomacoustictreatments.php

http://www.audioholics.com/techtips/roomacoustics/DIYabsorbersacoustics.php

http://avsforum.com/avs-vb/showthread.php?t=255432

link 1

link 2

link 3

Link

Link

Link

Ya beat me to it, you type to fast

Good linking guys. I was wondering why they don't link automatically like at other sites after cutting and pasting the links.