Does anyone play two pairs of speakers at the same time?

We did that in college. Nothing like two pairs of JBL driven by 60 watts of Kenwood and Pioneer (using only the highest quality lamp cord, it should go without saying) in a 8x15 foot dorm room. Totally recreates with perfect fidelity the experience of high sound pressure levels.

I started with one pair of Bose 901, but that was only 18 speakers. So then when the new Bose 901 came out I added a pair of those. 36 speakers! Yet something still was missing. The sound was coming at me from all over but mostly in front and way too similar. Some recordings I could still tell were different from others. So I kept adding speakers. B&W, ML, MBL, JBL, REL, got a good deal on some Klipschorns that filled in the corners real nice, set of Quads left and right side walls, half a dozen Totem bookshelf, was almost there and good thing too starting to run out of wall space! Yet something was missing. Then it hit me- the ceiling! In-walls to the rescue! 

That left only the floor. Which it turns out is mostly wasted space. Only a tiny amount of floor is actually doing anything. So now except for a foot path and enough to support the rack and chair its all speakers. 

Imaging? None! Immersion? TOTAL!

Yes because four sources makes for better bass. Lol!