The Mackie S518S - 18" Passive Subwoofer features an internal low-pass filter that focuses its power on the low frequencies of your signal. It can handle 900 watts program and 1,800 watts peak, allowing your audience to hear and feel the bass.
The S518S features a rugged wood enclosure with textured paint. The Subwoofer has both NL4 (Speakon) and 1/4" input and thru connections.