I have used my standard powered speakers (Mackie SRM450 or JBL PRX512) with the Compacts. These speakers are Wedge style, which makes them great for floor subs.
My Denon X-500 Mixer has a sub output, which only feeds low ends to what ever its plugged into.
This is great if you don't want to invest in extra subs, and need the extra kick, and as a bonus, it a backup active speaker!). It's also good to have with the Model 1 along with the B1 subs. Gives the dance floor a fuller base sound.