Distributed Bass Array configuration

Hello mapman,

      Funny, I have no trouble optimally positioning my subs in the room by ear, when utilizing the sub crawl method on each one sequentially, but I do have trouble optimally setting their phase by ear.
      I found it was much easier to optimally set the group phase on my subs once I turned off my main speakers.  The proper setting became much more obvious to me once I did this, I just set phase at the position at which the bass is slightly louder, more solid, more detailed and the most natural. 
     Another tip, which makes setting the proper phase on subs even easier to discern, is to temporarily invert the polarity on the main speakers (simply by reversing the positive and negative connections on each speaker's terminals), optimally set the phase control on the sub(s) and then swap the main speakers' connections back to normal. 
      This made a lot of sense to me once I learned that the phase and timing of sound waves are almost irrelevant on deep bass frequencies but critically important on midrange and treble frequencies.  Humans are much less sensitive to sound wave arrival times on deep bass tones than we are on tones over about 80 Hz.

Later,
 Tim

@noble101

I set it by ear initially based on what I thought the rolloff of the ls50 metas would be based on specs and reading and thought it sounded good. But I did not achieve my goal which was to fill in the low octave and leave what the mains delivered fine alone. There was a big bass bump from ~ 40-60 hz that was audible on most all tracks. The sound meter app clearly showed this. Room is not large, only 12X12 with lots of furnishings to help break things up naturally.  My crossover was way too high and the level way too low. Now things sound like full range speakers with extended bass. Much better though that is a subjective assessment despite the fact that the setup measures better now! You can only tell there is a sub on the tracks with extended bass to start with. I have full range speakers running in the next much larger room off the same system (no sub) to compare with.

@mike_in_nc , my solution to that problem is 1 slow the fan down, 2 change to a quieter fan or 3 disconnect the fan altogether and provide other cooling. It has a bigger processor and runs much faster.

Thanks to everyone who has participated. I’ve been reading a bunch of these DBA threads and it is causing me to seriously re-examine what I am currently doing with only one sub. For the single seating position that matters, it is invisible sonically, an REL B1 set at 23Hz with volume at 6/40 clicks, merely to augment small but deep floor-standers.

I did not hear a noticeable improvement in trying true stereo (L-R) subbing close to the speakers and went back to the single REL.

After reading and thinking, my mind (I prefer to be scientific) wraps around the DBA concept very well. I believe those who think they can localize the deepest bass are merely being fooled by other cues in their environment.

Needing at least a complete wave or more to identify pitch makes sense. Let’s throw out the ballyhooing over time coherency when you have to wait to even know what the first deep sound was…and your brain is moving off in other places already…

I’m now wondering (without any more spending) about trying three SVS sealed subs, two SB-2000s and one SB-300 in my 20.5 x 17ft deep room (with openings and canted ceiling) in place of the single REL (or two RELs with an old Storm III in my collection). Along with a really old Def Tech PF1500 sub I’m willing to make the music room best and give the extra subs to the dedicated home theater room (music rules).     Thanks again for the great discussion. Now I’m thinking.