Generally we set them to small. Crossovers are more of a personal preference, but the general concensus is to start at 80Hz and go from there. If you have crossovers available for each channel, things get a little more complicated--I have my M80s set to 60Hz (maybe 40?), VP100 to 100Hz, and QS4s to 120Hz, with the sub topped out at 120Hz.

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