Distributed Bass Array configuration

Any Sub Woofer set @ 80 HZ Crossover will interact with every Good Hi Fi Speaker's Bass Output.  This should be avoided.

Setting @ 60 Hz or so should minimize interference & blend in better.

With Sub Bass, a Crossover of 40 Hz or so would be appropriate.

1Hz XO resolution on subs and mains is nice.
Sub and mains may not necessarily crossover at the same frequency and more than probably at different slopes.

I often imagine that DBA is a lot like what happened in a mastering lab in the LP days: After listening to glorious 2 channel bottom end in the studio, it got sucked down to mono below 40Hz. And these guys recommend 80Hz w no XO on the mains. Surely you jest?

soundspectacular:" Please correct me if any of my comments here are incorrect as I don't claim to have any expertise. I do believe you are misinterpreting the "term" - "stereo subwoofers". It is a "term" not a sonic phenomena or an implementation in any recording process."

Hello soundspectacular,
 
     You are correct, "stereo subwoofers" is just a term, perhaps only used on this audio forum, that does not represent an actual phenomena or an implementation in any recording process. 
      I consider stereo subs a misnomer since I don't believe stereo bass even exists below about 80 Hz, iwe all perceive it as mono.  But others on this forum believe stereo bass below 80 Hz does exist. 
     The whole stereo bass subject on this forum, unfortunately, only gets more complex and polarized from there, as well as too involved to easily summarize.

Hope this helped,
Tim
     

A lot of the challenge is that while there is no stereo bass in the bottom octave or two, it does sound as if it is stereo. The drum whacks in Bird on a Wire, each one has a definite location. The hall ambience and cannon on Tchaikovsky 1812 are all incredibly precise. When people think of mono they think of Beatle's and other mono records where the sound all seems to be coming from a sphere in between the speakers. That is NOT what we are talking about! This bass does not sound as if it is mono. Not at all.  

However, rest assured, it most certainly IS mono! Anyone harboring any doubt whatsoever is welcome to come and hear, I am happy to demo, and you will hear absolutely zero difference when my DBA is run mono vs stereo. Zero. Nada. Zip. None. Because it is all mono! 

This actually even makes sense, because when you think about it, how else could it be? The wavelength of these low frequencies are so long, that in order to be picked up as stereo the microphones would have to be located a hundred feet or more apart. Even then, our hearing simply is not sensitive to timing at this degree of precision at this low a frequency. We don't even hear less than a full wave! Don't even hear it! 

This is where I think a lot of this comes from. Everyone is familiar with midrange and treble. Everyone knows the importance of phase, timing, etc. This is all goes right out the window with low bass.  

Also by the way with ultra-sonics. Super-tweeters, 40kHz, 60kHz, we cannot even hear. Yet they affect the sound in such a big way it changes our perception of even low bass!  

The mind is a strange and endlessly fascinating thing. Hearing is not just mechanical. We like to use a microphone as a metaphor for how we hear. But that is not all there is to it. The phenomenon of hearing is far more complex. The mind plays a vital role. Try and get your mind around it. 

One thing to keep in mind: if you are using a sub (or four) with---I would certainly hope ;-) ---a low-pass filtered signal as its/their source, well, what is the slope of that filter? If only 6dB/octave (1st-order, as with the Vandersteen subs), that sub reproducing a, say, 80Hz signal, will be reproducing 160Hz (an octave higher) at only 12dB down. Who thinks a 160Hz wave cannot be located in space? How about 320hZ (24dB down)? Naturally a higher-order filter will change those figures.

If you run your sub(s) in mono, that mono output will extend further up in frequency that the frequency at which the x/o is set, the degree to which is determined by the slope of the filter. It is for that reason that some prefer employing higher-order filters (both high-pass and low) to integrate speakers and subs.