Passives work fine as long as you don't have any interconnect cable. Otherwise they tend to limit bass and punch as you turn the volume control down. That's why we offer the option for the M-60s.
The MP-1 is specifically designed to control the interconnect cable, and as a result the cable between the preamp and amp is not critical and you can run really long lengths (+50') too. That allows you to keep the amps right by the speakers and run short speaker cables.
The MP-1 is specifically designed to control the interconnect cable, and as a result the cable between the preamp and amp is not critical and you can run really long lengths (+50') too. That allows you to keep the amps right by the speakers and run short speaker cables.