No need for an external amplifier to drive a subwoofer
Unlike conventional head units, the DSX-GS900 has amplifier power to spare, making it capable of simultaneously driving a subwoofer and a full car speaker system, including front and rear speakers. The unique 2-ohm load selector delivers high power without risking amp or speaker damage
Channel 1: front-left and rear-left speakers
Channel 2: front-right and rear-right speakers
Channel 3: subwoofer (mono)
45watts x 2 RMS to power all the interior speakers while still having a 90 watt RMS channel open to add a subwoofer with one easy radio install. No need for any external amplifier.