Distributed Bass Array configuration

@mijostyn -- An interesting story. I must correct you on one point. An expert is more properly defined as, "Anyone 500 miles from home." If one doesn't tell you what you want, another will -- they are a dime a dozen. I know; I was one (in another field).

I also had a TacT (2.2X) and a pair of Apogees (Caliper Signatures), though at different times. Flawed pieces, wonderful in their ways.

With subs, I always have used DSP HP and LP filters and careful adjustment of delay (phase). I have never used a sub without HP-filtering the mains, so can't comment on that idea. In my current setup, no one can localize the subs: bass seems to come from the main speakers, even though the subs are behind (!) the listener, placement needed to fill a room-induced response hole.

Since posting, I've played with a single added mono sub, and it seems to get my setup from 90% to 95%. (Some might not find that enough, but life is getting shorter.) I am mulling over how to adjust its delay -- my electronics aren't set up to do that, but I hope a sub with a continuous phase control will work well enough.

So in spite of terrific testimony you asked for- actual experience- you are playing around with the advice of one who has no actual experience. Par for the course. Oh well.

Moving along... In the interest of helping others following along, here is why crossing over the mains is self-defeating and a bad idea.

The key to excellent low bass is lots of sources of low bass. To the extent they put out low bass this includes the mains. Also more different locations helps, and while subs are almost always very near walls the mains are almost always several feet out. So crossing them over eliminates two very beneficial bass sources. In a realm where numbers matter far more than anything else this is known as a own goal.

Frankly and with all due respect you have no way of saying you got from 90 to 95% for the simple reason you have no idea what 100% sounds like. For sure the one you are taking advice from has no idea, he has never done this.

Once again I am perplexed and vexed at one who specifically asks for one thing- "those who use a DBA"- then turns around and follows one who not only does not use a DBA, but talks down anyone who does.

https://youtu.be/0t2pWUWE1Y8?t=8

Oh well, plenty of others willing to listen and learn. No point wasting any more time here.

@millercarbon  - I trust that my joking exchange about "experts" was not something you took personally. It surely was not aimed at any particular person.
I appreciate your contributions as well as those of others.

Of course not. Especially not since I agree, at least in my disdain for experts, and credentialism in general.

What gets me is what I said- asking very specifically for the advice of people with a DBA. But then when you get it you go with the advice of someone who not only has no DBA, but knows nothing about them, and in fact runs around threads like this where his lack of knowledge is expressly not requested, and spreads his bad advice as if he actually knows what he's talking about. 

I had a friend, an expert fisherman. This guy knows everything about everything when it comes to fishing. When another friend was looking for advice on a boat I naturally referred him to my fisherman guy. Who said sorry Chuck, I am not gonna help him. Why, Larry? Nobody knows more about this than you. "Because I don't want to waste my time" and then proceeded to tell me all about people he advised who then ignored everything he said. So he doesn't do that any more.

Me, I am more selective. No hard feelings. No more help either. I'm sure you understand.

Its not just me by the way. Read the thread. You disrespect Tim as well. So basically the only two guys to give you what you ask for you disregard and disrespect. 

I hope a sub with a continuous phase control will work well enough.

Nope.

"All-Pass phase controls operate at only a single frequency with varying degrees of shift across the passband."

see http://www.ielogical.com/assets/SubTerrBlues/PhaseControl.png at  ieLogical SubterraneanHomesickBlues for an image of how a continuous phase control functions.