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Room modes are hijacking my music

My listening room is resonating in the 60-300 Hz range. I've been living with this boominess for quite a while, but I thought it was just the nature of a ported speaker (Dahlquist DQ-30). In an effort to tame it, I attenuated power to the woofers via biamping, but the results were spotty and less than perfect. Some material needed more attenuation, while others needed less. It was a pain to go through this when I just wanted sit down and listen to music.

Well, I recently picked up a pair of Alon Model I's which have an 8 inch acoustic suspension woofer, but the problem continued. I was puzzled at first because I knew the Alon's shouldn't sound like this. That's when it dawned on me that it wasn't the speaker, but the room. So I started playing with an equalizer to level out the bass and the results have been nothing short of staggering. By reducing the signal as much as 8-10 dB at 125 Hz and gradually flatting the dip back to zero at 32 Hz and 500 Hz, I've completely eliminated the boom and now hear deep tight bass. The improvement is stunning and the speakers sound amazing! I can't emphasize this enough. Of course, I don't want an equalizer in my signal path! So, I'm faced with the task of taming my room with absorption materials. I'm not thrilled about this. Decorating my walls with R50 insulation blocks dressed in some fabric is not my idea of modern art, but I don't see any other alternative. How have others dealt with this problem? I can't (and won't) ignore it.

I've learned a big lesson here. We're hard wired into thinking that upgrades will improve our system. We're so focused on the equipment that we often overlook abstract considerations. I'm generalizing, but you get the idea. Most people throw money at their system hoping it will improve.

FWIW, my room dimensions: 15' x 17' x 9'

Insights and suggestions are warmly welcomed.

Mark
mingles
mingles OP
796 posts
 
Thanks everyone for the suggestions. I appreciate your feedback. I've tinkered with speaker placement and listening locations, but it does nothing to reduce the boom. My room is nearly square. According to those in the know, "a perfectly square room will have fewer resonances but they will be stronger in magnitude." The resonances I'm hearing are very strong.

Ryan Allen's case study is encouraging, but I'm not excited about the appearance of floor-to-ceiling bass traps in my living room. Maybe I need to get over this. I suppose I could make the traps to keep the cost down and evaluate their effectiveness without investing too much.

I think the best solution might be a combination of smaller bass traps and an equalizer. There's no doubt in my mind that an equalizer will tame the boom, but if I make extreme adustments, it introduces phase shifts (according to what I've read). If I can keep the adustments to a minimum, the shifts should be minimal.

The equalizer I've been using is built in to iTunes, so it's not a long term solution. It only works with music played through iTunes, so I need to buy an equalizer. Can anyone recommend a high quality unit that can finely tune frequencies between 30 and 500 Hz?
mingles OP
796 posts
 
I stumbled upon a nice review of the Behringer DEQ2496 Equalizer:

http://forum.audiogon.com/cgi-bin/fr.pl?rprea&1107728225

It does exactly what I'm looking for.

My question: can an RTA equalizer be isolated to the LF signal if you're biamping? Or does it need to look at the whole audio spectrum to function correctly? My speakers crossover at 500 Hz with second order filters. The resonances I need to tame are between 30-250 Hz. In theory, it should work with just the LF. Any thoughts?

Does anyone have experience with RTA equalizers?
lewhite
156 posts
 
Sardonyxx Headphones are very close speakers :} and they shift room nodes up in the 10k area were they are much less audible so you are correct ! I use the opposite approach and use two subs at about elbow reach ,turned down very low as not to excite the room and over or underlap as room nodes require.(some were around 60/70Hz )
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