Smoother bass by running woofer 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.

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

I agree fully with that.

I guess what sounds best to your own ears is the right thing to do...

If you are listening to a bass guitar or double bass then I agree that phase has very little to do with the way the notes sound.

However the fact that the bass sounds more spacious with one speaker woofer wired incorrectly seems to me to imply that there is enough energy in the upper bass (perhaps above 80 Hz) to give some rough directional information to the ears - surely this must affect presentation or the way transients sound - like a Kick drum where the slap comes at 4 or 5 Khz and bottom at 60 to 80 HZ?. By this I mean coudl it change the perceotion of fast bass versus slow bass.

I would dig out the Sheffield Labs Drum test Track 1 and check to see which sounds better/more realistic (disregarding the overly heavy bass presentation by using a tone control for example). Just a thought....

Here is and example of the funky relationship between bass mid and treble and the way we perceive instruments

The jargon is an interesting mix of descriptive words to describe how something sounds coupled with the frequencies that are driving that sound. I would be concerned with changing teh way thing sound through incorrect phase....it may not sound that much wrong but it may sound different.

From what I gather from you the experts I should wire the woofer in phase and look into finding what frequencies are giving me trouble; then use some type of EQ to take care of the bass nodes. I wonder if my wife will get me a Rives prac for Christmas? Stay tune, I will let you know how this will all work out. Thanks- Sam

One other comment relative to in-room bass smoothness: Note that fullrange dipoles have smoother in-room bass than monopoles (James M. Kates, "Dipole Loudspeaker Response in Listening Rooms", JAES May 2002). A single dipole may be thought of as two monopoles out of phase with each other. I think there's some merit to the idea of playing around with driver phase in the deep bass region.