Smoother bass by running woofer out of phase?


In my dedicated room that is furnish with bass traps, I still get to much bass energy on bass heavy music. I discover recently that in bi wiring my speakers (ML Vantage)I wire the woofers out of phase;the bass bloat goes away and I have greater detail from top to bottom. What is the explanation of this and is this a recommended "fix" in dealing with excessive bass? Thanks, Sam
shum3s
My room dimension is 13x30. I have the speakers set up on the short wall. The speakers are 5 feet out into the room and 2 feet from the side walls. Listening chair is 9 feet from the center plane of the speakers. The floor is concrete with double wall construction. My ceiling slopes from 10 feet to 7 feet from left to right. Carpeted in the seating area bare painted floor in the speaker end. Perhaps then my only solution will be to applied some sort of EQ in the low freq.region. Thanks guys for your input.
Interesting that you find that it sounds better with the woofers out of phase, in as that back in the early '90s, when Stereophile reviewed the Martin Logan Sequel IIs, that they too found that if they wired the woofer out of phase, that it too sounded better.

Thought you might find that interesting.
The other issue I did not mention will be cancellation or a dip in the crossover region on the one speaker that is wired out of phase.
The ear literally responds slowly at very low frequencies. We cannot hear less than 1 cycle at very low frequencies, and by the time 1 cycle has reached us enough time has elaped that we're past the direct sound and into the reverberant sound. Unfortunately I don't know the (probably fuzzy) cut-off point for this phenomenon. But it can be said that from the standpoint of psychoacoustics, there is no "direct sound" in the deep bass; at least not in the size rooms we typically have at home.

The increase is spaciousness is probably somewhat artificial because very few recordings actually have stereo information below 80 Hz. The ear interprets a low-frequency phase difference at each ear as a sign of very large acoustic space, and that is what is being synthesized by reversing the phase of one of the woofers. Out-of-phase subwoofers placed to the extreme left and right of the listening position will maximize the interaural phase difference and hence the simulated sense of spaciousness. David Griesinger, inventor of the Lexicon processor, advocates this technique.

Duke
dealer/manufacturer
Shum3s...hold yer horsies fella!! Funny how the obvious escapes most people, but not this here audiophile..no sir. What ya gotta do is move them pesky speakers to the long wall and sit within 18" of the opposite wall. Spread them out real good..10 to 12ft, and bring em out by ear until you achieve the best darn response you can get! Also, sit with yer ears below 36", and treat the front and back walls with acoustic material (natural nor not). You cannot decide where you will sit and place speakers...the room and the speakers decide, otherwise get a Bose radio.