This 2.1 Class D amplifier delivers 2 x 50W @ 4 ohms or 2 x 25W @ 8 ohms to the speakers plus 100W @ 4 ohms or 50W @ 8 ohms to the subwoofer. For the subwoofer, the unit has crossover frequency adjustment, as well as level, tone and volume controls. This unit also features Bluetooth 4.0, 2 x RCA line level, 3.5 mm jack inputs and a source selector knob on the front panel.