Advise on acoustic treatments to fix boomy bass.


Have speakers that I really like. Problem is they need to be out from back wall about 36". Closer and the bass gets boomy. They are a ported bass reflex design. Anyone have any experience with acoustic treatments that will remedy this situation and allow a placement closer to rear wall? If so, please provide specifics.
j_bailey
Audio Asylum. Look up member Jon Risch. All you ever wanted to know (and more).
Be certain to check the Room Acoustics forum (sponsored by Rives Audio) on Audio Asylum which has a ton of information. Ethan Winer (musican and owner of RealTraps) is a frequent contributor there and his web sites are a "must" read for those interested in room acoustics and treatment. The Rives Audio site is also an excellent resource.

There are a number of suggestions that could be made, but educating yourself a bit first will probably be the most useful. You may also want to consider doing some rough room measurements using the Radio Shack SPL meter and Rives Test CD. They can be purchased for less than $75.

One thing you might want to try is Jon's "down and dirty" bass traps which are essentially bags of rolled insulation stacked in the room corners. Not pretty, but inexpensive and quick and they will give you a hint at what's possible.

I've treated my room with custom bass traps in all four corners using a design based on Owens Corning rigid fiberglass panels. Also treated first reflection points and some other areas. The improvement in the sound is significant and at least as important as any component upgrade.
This is going to be a different kind of suggestion, but, hey, I seem to go against the grain.

Despite the "conventional wisdom" that you NEVER stuff a ported box, I find it does away with most, if not all, of that boxy sound a ported speaker can exhibit. I was told this by a well known speaker guru, whose unorthodox ways provide a tremendous amount of speaker improvement at such little cost, it's laughable. His recipe, pick up some polyester batting from a discount store (fabric, KMart, WalMart, etc.). Tear off medium sized handfuls, not too tight, and loosely throw them into the box. Fill it up about 75%, remembering that too loosely is preferable to packing it too tightly. You can facilitate this by removing the woofer from the speaker, then putting it back after your finished. No need to disconnect the driver.

And, if it sounds totally crazy, just remember that Bud Fried's Line Tunnel and what Von Schweikerts calls their "transmission line" is nothing more than a ported speaker, stuffed with foam. Neither of which produce boxy, boomy bass.
Thanks guys. I'll check it all out. Probably more fun and easier to spend money on some new gear, but my room definitely needs help.