Tried 2 pairs of speakers for 2 channel?

Has anyone tried (sucessfully or not) using 2 pairs of main speakers for a 2 channel setup? I am talking pairs of identical speakers, powered by 2 identical amps. Any recommendations on placement would be helpful.
Place the speakers back-to-back. You'll have a bipole sound radiation pattern with sound emanating from the front and back and diminished levels to the side. Mirage has made a number of great sounding speakers along this design principle. You'll need to position the speakers so that there's plenty of space to the rear wall (3 feet minimum, but the more the better). You should get a big, spacious soundstage with large-scale dynamics. All the setups will result in noticeable phase inteference problems.
With Double Advents, how do you correctly wire the speakers if you are using one amp? I read how to stack them all the time, but how do you correctly run the speaker wire to connect the 2 speakers on each side?
You might want to read the number 7 tip from the above site. It touches on placement of two pairs of speakers, placement and wiring. Sounds interesting, although I personally have not tried it.
I have built several experimental bipole systems.

One disadvantage of a bipole setup is that you will probably get a severe dip in the on-axis frequency response at the frequency where the path length difference from the woofers to your ears is equal to 1/2 wavelength. The dip would probably be in the lower midrange or upper midbass region.

It is possible to design a system that minimizes this path length difference dip (and indeed Definitive Technology holds a patent on one such technique), but you have to design the system specifically to address that issue. It is very unlikely that placing two identical speakers back-to-back would work.

You may still like them in bipole configuration, as dips are less audible than peaks.

i owned 2 pair of quad esl 57 speakers, which were stacked in a mark levenson stand.

as an experiment i tried running 2 pairs of different speakers, one behind the other. yes, i am aware of the problems. it was just an experiment--an interesting one at that.