Passive sub for live or DJ systems.
The Mackie S518 is a passive subwoofer with an 18" LF driver. It has a peak handling capacity of 1800 watts. It is an 8 ohm cabinet.
It is made of wood which, aside from being sturdy and all-natural, provides the best-possible response, extended low-frequency output without annoying rattles or vibrations. Plus, substantial internal bracing provides a more rigid enclosure, reducing nasty vibrations that could negatively affect sound quality.
Lastly, the entire acoustic chamber is air-displaced with adiabatic acoustic batting. This dampens internal midrange reflections so they can't bleed back through the LF transducer cone and reach your ears, which causes inferior enclosures to sound "boxy." This, along with LF porting, also allows Mackie S500 enclosures to deliver huge sound in a more compact design than otherwise possible.
The bumpers have built-in cups for stacking multiple full-range loudspeakers along with sturdy integrated side handles with an ergonomic design that's great for transportation.