JBL S2-1224SS Slipstream™ bass reflex subwoofer 12" (300 mm).

JBL S2-1224SS (CLUB series) Slipstream™ bass reflex subwoofer 12" (300 mm).

Long excursion design
The longer a subwoofer’s excursion is, the more air it moves. And the more air it moves, the more bass you feel. 
The long-excursion design in Series II enclosure ensures big, deep bass output. Just the way you like it.

Slipstream™ port design
At high sound pressure levels, air flow turbulence inside a vented enclosure’s port can create noise that sounds like woofer break up. 
The patented Slipstream port in Series II enclosure uses a double-flared design to minimize turbulence, and eliminate unwanted vortices.

SSI™ (Selectable Smart Impedance)
Most car audio system designs call for 2- or 4-ohm impedance. 
Series II subwoofers feature an exclusive dual impedance switch that lets you choose either load impedance option. 
Not available from any other manufacturer, SSI lets you reconfigure your system by simply flipping a switch.