MB Quart Reference series five channel car audio amplifier featuring innovative sound quality and power technology to run four full range channel and a subwoofer channel. The RA1-710.5 is a 700 watt 1 ohm stable (channel 5 only) car audio amplifier. Reference amplifiers feature DC Sensing to allow any amplifier to be easy integrated into an OEM system by simply adapting a RCA cable from the source unit. Bass remote is included.