The sub woofer is a Pioneer Model TS-WX100BP 300 Watt 4 Ohm Car Subwoofer. New in box, $150.00. The amp is an Alpine MRV-M250 Mono subwoofer amplifier, 250 watts RMS x 1 at 2 ohms. Call or text 52zero 37 zero 395one. Note, The Sony XM-504X has been sold.