Ten2 Series plus4 Two-way sealed speaker system, 10 down firing woofer, 10 front firing woofer, 2.5 coaxial tweeter Exclusive Room Coupling Control(tm) to help tame boomy acoustic settings Cabrio Docking System(tm) means head is removable for use as stand-alone unit Three-band EQ preamp section per channel Effects loop with return level control per channel