Distributed Bass Array configuration


Please, I don't want to debate the merits of the DBA nor of those who espouse it. I am considering adding two more subwoofers to a system that has two already. To those who use a DBA,I am interested in how you have configured them, specifically--
  1. Do you run in mono, or do you split the array to run in stereo?
  2. What is your approach to setting phase (delay) among speakers that may be facing different directions and are different distances from the listener?
Thanks!
mike_in_nc
I find in practice extremely minor adjustments to my sub level are needed to get it tuned in exactly to my ears, which is consistent with what Duke is saying. Very minor....
Yes, Duke agreed with me suggesting level matching as a good starting point. Thanks for pointing that out.

Sorry MC, you're a dart thrower, here's what you said. Guaranteed your system would sound better if you learned to install it correctly with the right tools. You're the one adjusting the bass whenever the next 'more bass on this song, better turn those subs down again'. If you learned how to use the tools you wouldn't need to do that.

" What I did, once the initial phase is done, was listen to a lot of different music at my normal levels. I abhor meters. Most of the time I listen at a nice satisfying volume level. Sometimes not that loud. Occasionally I listen Supertramp Loud. Gradually, over time, I make really small level adjustments. Really small. Like I turn the knob but about half the time not really sure it did anything. This works because the meaning of the equal loudness contours is we go from being relatively insensitive to bass at low volume to hyper sensitive to bass at high volume".
Question:   
When using the crawl method and picking the best spot for Sub #1
are you supposed to then power up Sub #1 while crawling for Sub #2`s best spot and so on with each sub thereafter....??

Duke- This is what I was talking about, and once you understand that, it will be clear why a small change in gain on the subwoofer amp typically results in a larger than expected change in perceived loudness. Or, to put it another way, why it takes a while to dial in the gain setting on a subwoofer amp.
MC- Gradually, over time, I make really small level adjustments. Really small. Like I turn the knob but about half the time not really sure it did anything. This works because the meaning of the equal loudness contours is we go from being relatively insensitive to bass at low volume to hyper sensitive to bass at high volume".


golfnutz- The difference between the two is: MDS.
@scm asked, " When using the crawl method and picking the best spot for Sub #1 are you supposed to then power up Sub #1 while crawling for Sub #2`s best spot and so on with each sub thereafter....??"

Yes.

When doing the Crawl to set up a Swarm or DEBRA system, which uses a separate amplifier, connect the additional subs in series, such that the overall subwoofer volume level stays the same. If doing your own distributed multisub system with conventional self-powered subs, I think you’d want to adjust the volume of the pre-existing subs before adding yet another, and measurements would probably help a lot with this.

Duke