I have a two channel preamp and run one channel through a McIntosh MC302 amp and the other channel through a Bryston 4Bsst2 amp. One amp is connected to a pair of Pardigm signature S8V3 speakers and the other through vintage JBL L150 speakers. I have the right channel/left channel speakers pretty close together and spacing between the pairs of about 6 feet. This is an odd setup, mating more efficient modern Paradigm speakers with vintage less efficient JBL's so I adjusted the gain on the Bryston amp to match it better. I do like the sound of this setup, but sometimes go with individual pairs depending on the constellations or horoscope or something like that...
Does anyone play two pairs of speakers at the same time?
I have found that certain combinations of speaker pairs produce a better sound than the single pair alone. For example: Klipsch Quartets and PSB Image 4T (new tweeters from Vifa) Quartets inside pair and volume matched to PSBs. I have done this over the years and found some great combinations.