Sundown U-Series 8″ v.1 D4 Car Audio Subwoofer

U-Series 8-inch v.1

This listing is the D4 (dual 4-ohm) version of the U-Series 8-inch v.1 subwoofer. Official published power is 750 watts RMS and 1500 watts peak. Sundown positions the U-8 above the SA-8 v.3 for power handling, Xmax, and output potential. Do not confuse this v.1 8-inch model with later or larger U-Series versions that use different power ratings.

Motor, frame, and excursion

Official features include an aluminum 2.25-inch voice coil former, high-temperature copper voice coil, double-stitched surround, heavy-duty cast basket, and spring-loaded terminals that accept up to 8-gauge wire. The custom tooled frame is covered by U.S. patent D691595 and is designed to allow a larger spider and more clearance than a typical 8-inch woofer. Official one-way linear Xmax is 18 mm, with mechanical capacity described as more than double the linear limits (about 2.5 inches peak-to-peak). The surround geometry follows Sundown’s larger Mega-Roll v.2 profile. A solid pole with vent channels, an aluminum shorting-ring cap, rear gap venting, and top-plate cooling channels complete the motor.

Mounting dimensions

Official enclosure specs shared by the D2 and D4 versions list an overall diameter of 8.70 inches, a cutout diameter of 7.375 inches, a motor diameter of 6.88 inches, a mounting depth of 6.02 inches, and 0.09 cubic feet of displacement.

Enclosure guidance

Official sealed volume is 0.25–0.35 cubic feet. Official ported volume is 0.65 cubic feet with a 35 Hz port tuning and 9 square inches of port area. Fourth-order sealed and ported figures are also published at 0.225 cubic feet sealed and 0.675 cubic feet ported, with 14 square inches of port area and a 6-inch port length. The amplifier and enclosure are sold separately.

• 8-inch U-Series v.1 subwoofer with dual 4-ohm voice coils
• 750 watts RMS and 1500 watts peak official power ratings
• 18 mm official one-way linear Xmax
• Aluminum 2.25-inch voice coil former and high-temperature copper coil
• Patented cast frame (U.S. patent D691595) and heavy-duty basket
• Spring-loaded terminals accept up to 8-gauge wire
• Official mounting depth of 6.02 inches and 8.70-inch overall diameter
• Official ported guidance of about 0.65 cubic feet at 35 Hz

• Requires a compatible amplifier and enclosure (sold separately).
• Wire the dual 4-ohm voice coils for the intended final load.
• This is the U-Series 8-inch v.1 (750 W RMS), not a later U-Series version.
• Professional installation is recommended.

• Sundown U-Series 8" v.1 D4 subwoofer

• Sundown U-Series 8" v.1 on manufacturer site