I started this thread in response to Gasman’s post in the following thread which I didn’t want to hijack.
http://forums.audioholics.com/forums/showthread.php?t=36272&page=2
Originally posted by Gasman
WOW, I find that strange. 240Hz, are you sure?
"The voiced speech of a typical adult male will have a fundamental frequency of from 85 to 155 Hz, and that of a typical adult female from 165 to 255 Hz."
Have you tried the rattle test? Frequency sweep?
I would have to say, that there really should be no 'boomyness' at 240Hz.
If you do, then you have major room conditions (reflections, I would think) that need correcting. (possibly, toe speakers out)
Or if you have a AVR with built in EQ, I would turn the mid-range down.
I used the AutoEQ built into my Denon 2807 and it took care of the boomyness. However, it made the center and mains sound hollow and tinny. It has a manual EQ with I think 16 bands. When I copied the Auto EQ settings over to the manual EQ it was setting the 125Hz and 250Hz bands to -4db for the surrounds to -8dB and -10dB for the mains and center respectively. So I did a frequency sweep and it showed the worst problems were +5dB at 20Hz, -7dB at 40Hz, +10dB at 168Hz and +12 dB at 240Hz. The only rattling was happening as the sweep dropped below 30Hz.
I got rid of the 30Hz problem by stuffing a T-shirt in the subwoofer port.
Moving the main speakers out from the front wall from 2.5 feet to 4 feet and moving the seating back 2 feet knocked -3dB off the 168Hz and 240Hz peaks. I had already placed the subwoofer in the best place I could find to reduce the boomyness. Setting the manual EQ for 125Hz low enough to help made male voices sound tinny but didn’t get rid of all the boomyness. Lowering the 250Hz band then got rid of the rest of the boomyness but made the speakers sound hollow.
At the suggestion of a friend I put a mattress up against the wall opposite the mains/center which knocked -3dB off the 168Hz and 240Hz peaks. Which made the EQ level necessary to get rid of the boomyness more livable.
The problem is that moving the speakers and the seats messes up other things so I moved them back.
Unfortunately my room is a square with only a partial wall separating the kitchen. It’s also an apartment so there are some limits to what I can do. However as long a I don’t put holes in the wall the landlords are cool about it. For example I’ve built a frame of 2x2s around the viewing area and hung black curtains so adding some room treatments wouldn’t be a problem.
The main reason I am even sweating this is so that I will hopefully learn enough about room interactions so that when I buy a house I can know what I’m doing and plan ahead.
Suggestions about room treatments, equalizers or anything else are welcome.
