This amplifier is made for optimal performance for both 2 and 6-channel systems. The amplifiers use the new Electrocompaniet standard SPAC, (Serial Power Amp Control), to switch between 6 channel and 2 channel system! The new Preamp (EC4.9), will automatically switch this amplifier into a 1×400 mono as soon as you play 2-channel music, or select this from the remote controller.