Sundown Audio SA-6.5SW 6.5" 300w RMS Car Audio Subwoofer DVC 2-Ohm SA Series Sub

The SA-6.5SW D2 exists for one reason: real bass in under four inches of mounting depth. It handles 300W RMS and 600W peak on dual 2-ohm coils, in a 6.5-inch frame that measures 3.75 inches deep with a 5.875-inch cutout.

Sundown uses a solid-pole design so the back plate can rest against the rear wall of the enclosure, which trims the depth requirement even further. That is the difference between a sub that fits under a truck seat and one that does not. With 10mm Xmax and 20mm of mechanical excursion, this small cone moves far enough to produce genuinely deep output rather than the thin midbass most compact subs manage.

A large aluminum faraday ring keeps distortion down for an even response, high-temperature voice coil wire handles the thermal load, and integrated vent channels add cooling. Spring-loaded terminals make wiring quick in a cramped install.

Box requirements are small. Use 0.15 cu ft sealed for tight bass in a stealth box, or 0.3 cu ft ported with 4 sq in of port tuned to 40 Hz for more output. Cone displacement is only 0.02 cu ft. Common builds include under-seat and behind-seat enclosures in pickups, door-panel and kick-panel boxes, motorcycle and side-by-side setups, and small sealed boxes for cars where cargo space cannot be lost.

The dual 2-ohm coils wire to 1 ohm for a small monoblock, or 4 ohms for a full-range amplifier channel.