Sundown Audio SA-15 V.3 D4 15" 1500w RMS Car Subwoofer DVC 4-Ohm SA Series Sub

The SA-15 V.3 D4 is a 15-inch car subwoofer rated at 1500W RMS and 3000W peak, built around dual 4-ohm voice coils. It has 22mm of one-way linear excursion and a 40mm mechanical limit, so the cone still has travel in reserve when the bass line drops. Sensitivity measures 87.4 dB, which keeps output strong for the power applied.

The dual 4-ohm version exists for wiring flexibility. A single sub wires to 2 ohms in parallel or 8 ohms in series, and a pair of them drops to 1 ohm for a big monoblock. That makes this the right pick when you are planning a two-sub system or already own an amplifier that is happiest at 2 ohms.

With a 35 Hz free-air resonance and 50.4 L Vas, box options are wide. Use 1.5 cu ft sealed for tight, accurate bass, or 3.0 cu ft ported tuned to 35 Hz with 44 sq in of port area for more low-end output. A bandpass build calls for a 1.5 cu ft sealed side and a 4.5 cu ft ported side with 90 sq in of port and a 6-inch port length. Subtract 0.22 cu ft for cone displacement.

Mounting is trunk-friendly: 9 inches of depth, a 15.6-inch outside diameter, and a 14.1-inch cutout. It fits hatchback boxes, trunk walls, and truck-cab enclosures without custom depth work.