The 1800SX compliments the P-Series with low frequency extension. The powered subwoofer employs an 18-inch woofer with a custom 2000 watt Class-D amplifier. The large woofer and matched amplifier are enclosed in a multi-ply hardwood cabinet, the combination provides a superior punch and extreme low-frequency response, which are both Cerwin Vega! trademarks. Like the two tops, the P1800SX has frequency-shaping controls and the unrivaled VEGA BASS boost. This ensures the user can dial in the correct amount of bass for each venue. While designed for use with the P-Series full-range tops, the P1800SX can also be used for low frequency extension with other Cerwin Vega! tops or even other brands. Additionally, the THRU, MIX and LINK outputs allow for system expandability and fast daisy-chaining between components.