Bad room, bad tunes

Ohlala: Look in Stereophile Guide to Home Theater for an archive with a worksheet where you can run calculations with different speaker positions and that will provide you (hope) a position where less increment and better allaround bass response might be achieved. This are guides and I recommend you get the SPL and play with positioning. Good luck

Nice response, Audiopath, but I too question whether the Hales aren't just too damned big for the room? 6.5 or even 5" two-ways would suffice here, no? And if your calculations show THAT big a 100 Hz bump wouldn't even something truly anemic but musical (even NHT zeros?) be worth a try?...once he tames those sidewalls! Good luck.

Adding only a possible little to Audiopath's extremely useful suggestions, you might read F. Alton Everest's "Sound Studio Construction on a Budget". You aren't going to have a power saw, alas. If you did, I have DIY designs for Argent Room Lens clones and RPS-style diffusors made out of Styrofoam what I'd be glad to pass on. Mixing diffusion in with absorption is a good idea, and the commercial RGP Skyline diffusors are available from Audio Advisor, maybe for $125 per 2 square foot unit (from a friendly salesman).

Thanks, that was very helpful.

Yo Ohlala, As for the modes (standing waves), you have two ways to go...treat the room or treat the bass problem electronically. The first thing you need to do is the math. Your room is resonating at 100hz & 110Hz from the primary and the first axial mode and 137.5hz from the other axial mode. The big problem it the double whammy at 100~110Hz. Those freqs. will be 9db louder than the rest of the midbass. You should start by looking at the ASC Tube Traps (http://www.tubetrap.com/) for the corners. Contact them for suggestions on what sizes and how many to start with. If you can’t afford them, then you can make your own versions using cardboard concrete forms and fiberglass insulation or foam insulation. As for the treble problems, they can be solved fairly easily using ready made or diy absorbers. Start with the side walls. Two inch thick white foam that you can buy at cloth and camping stores will work in a 2 x 4 sheet... if you cover it with a double knit cloth it will even look nice. Start with 8 of them: 2 each for the center of all 4 walls. Use a hot glue gun to attach the cloth and then velcro or glue the finished product up on the wall. Cut the corner pieces from an 18” square into a triangle and fold it into a “v” shape. Then stretch the cloth over the top and two sides and glue it in back. It will be hollow inside. The 2” foam will glue up or velcro into the corner. As for the electronic solution, you will need an electronic crossover for a subwoofer to roll off the bass at 24db/octave below about 120hz. Then use a small sub set at 80hz to fill in the bottom. Using a sound pressure level meter ($30 at Shadio Rack) you can adjust the sub's volume control until it levels out below 100hz. Buy the Stereophile Test CD #2 for the bass test tones.