DESC: Unlike conventional mono subwoofer amplifiers that only deliver their maximum power into a single impedance, the BPX500.1 is a two-channel amplifier that can be bridged to deliver double the voltage of a single channel into impedances between 2 and 4 ohms. The two channels can also be connected in parallel - that''s right, parallel - to provide double the current of single channel into impedance below 2 ohms. This feature is patented and unprecidented in car audio amplification.