Who knows how to set up a bass swarm? (DBA)


I recently upgraded from Martin Logan ESL-X to ESL 13a. I had a pair of REL t7i to go with my esl-x. The new speakers have dual 10 inch Powered subs in each speaker. 
I feel like I could now use my REL subs as part of a DBA now, but I don’t really know how that works. For example, where would I place the subs? What level do I put them, where do I crossover, what’s the air speed of an unladen swallow? 

Who can help? 

andrewkelley
@millercarbon yeah I would never crossover the esl 13a, I probably didn’t communicate that right. I was wondering where I should crossover or “low pass” the subs but by reading yours and @audiokinesis info it looks like I want to low pass them pretty low so I don’t give away their location. 

Will I lose imaging of bass instruments? 
No, it is if anything even better. Don't know for sure why that is. Probably because smoother. Maybe Duke knows why. All I know is in spite of having 5 subs you never get the impression any of them is doing anything. In the beginning I would even sometimes go over and touch a woofer to make sure it was even connected! 

Read the description on my System page https://systems.audiogon.com/systems/8367 where Mike says " Excellent tonal balance and wide, pinpoint soundstage! Bass was tight and articulate and seemed to be coming from everywhere, but well integrated with the music, band, performance. Never boomy or out of control." In other words the bass is an integral part of the sound stage and imaging. 

My hunch is this is because our sense of imaging location comes from a frequency range quite a bit higher than the subs go. With only one or two subs the low bass isn't smooth enough to fully integrate and so the sense of imaging is weaker. With many subs the bass is very smooth, there's even less auditory cues telling you where it might be, and so the superior imaging cues from the higher frequencies take over and you "know" where it is, even though at that low a frequency there's just no way you would know. 
If a swallow summers in Spain and winters in North Africa, which continent is it from?