Sundown Audio

SUNDOWN AUDIO U-65 6.5" Subwoofer D2 | 400W RMS - 2 OHM

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  • Sundown Audio SUNDOWN AUDIO U-65  6.5" Subwoofer D2 | 400W RMS - 2 OHM
  • Sundown Audio SUNDOWN AUDIO U-65  6.5" Subwoofer D2 | 400W RMS - 2 OHM
  • Sundown Audio SUNDOWN AUDIO U-65  6.5" Subwoofer D2 | 400W RMS - 2 OHM
  • Sundown Audio SUNDOWN AUDIO U-65  6.5" Subwoofer D2 | 400W RMS - 2 OHM
MSRP: $191.99
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SUNDOWN AUDIO U-65  6.5" Subwoofer D2 | 400W RMS - 2 OHM

Introducing the Sundown Audio U-6.5 Subwoofers with D2 Voice Coil!

Prepare yourself for an audio experience that will redefine your expectations. The Sundown Audio U-6.5 Subwoofers with D2 Voice Coil are here to revolutionize your sound system with their exceptional performance and unmatched power.

Equipped with a robust 400W RMS (Root Mean Square) driver, these subwoofers deliver an extraordinary level of performance. Whether you crave earth-shattering bass or flawlessly crisp lows, the U-6.5 Subwoofers are engineered to exceed your every desire.

The D2 Voice Coil configuration of these subwoofers provides you with unparalleled flexibility in optimizing your audio setup. With its dual 2-ohm voice coils, you have the freedom to customize your system and extract the most from your audio experience.

What sets the U-6.5 Subwoofers apart is the cutting-edge "W" surround technology, inspired by the successful SD-4 model. This surround is meticulously designed using Finite Element Analysis (FEA), ensuring optimal mechanical performance. Its increased stiffness near the limits prevents damage and ensures the subwoofers can handle even the most demanding audio conditions.

In perfect harmony with the surround, Sundown Audio is developing a specialized spider that is tailored specifically for the U-6.5SW model. This intricate combination of components guarantees flawless performance and creates an audio experience that will leave you in awe.

When it comes to excursion capabilities, the U-6.5 Subwoofers with D2 Voice Coil offer an impressive one-way linear X-max of 19mm, reaching an astonishing 70% BL. The exceptional excursion is backed by a substantial amount of motor force, resulting in unparalleled sonic precision and impact.

Unlike previous models, the U-6.5 Subwoofers are not limited by depth constraints. Sundown Audio has spared no effort in designing a subwoofer that delivers outstanding performance without sacrificing size or form factor.

Get ready to redefine your audio experience with the Sundown Audio U-6.5 Subwoofers with D2 Voice Coil. Elevate your sound system, make a statement, and immerse yourself in the true essence of music. Prepare to unleash the power of exceptional sound!


RMS: 400W
Black Aluminum 1.753” voice coil former for superior heat dissipation
High Temperature Round-Wire Copper voice coil
Double stitched surround
Heavy duty cast basket
Spring loaded terminals accept up to 8 gauge
Stitched-on heavy-duty tinsel leads
Solid pole with vent channels and aluminum shorting ring cap
Rear drilled gap-venting
Magnet ID shorting ring
Top-Plate Cooling Channels
Optimized for small ported enclosures

RE (Ohms) 4.0586 6.6274
FS (Hz) 41.9533 38.6925
VAS (L) 2.9053 3.7701
Qes 0.5238 0.5005
Qms 8.5834 7.2470
Qts 0.4937 0.4681
Le (mH) 4.0112 5.5892
BL (NA) 16.7428 20.0082
Mms (Grams) 137.2546 124.3518
Cms (uM/N) 104.8528 136.0613
Sens (dB @ 1w/1m) 77.8706 78.1460


Ported Enclosure
Size: .25-.35 cuft net
Port Area: 4-5 sqin
Port Tuning: 35hz -40hz

Sealed Enclosure
Size: 0.125-0.2 cuft net
Displacement: .04 cu. ft.

Physical Dimensions

Depth: 5.71"

Outside Diameter: 7.17"
Cutout: 5.94"

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Warranty Information

Warranty Information

Sundown Audio requires us to send customers with equipment problems directly to them for all warranty and non-warranty claims. Please follow their proceedures..


Sundown Audio RMA form:

Sundown Audio Product Warranty Information:


Sundown Audio - Hours of Operation

Monday 9am - 5pm EST
Tuesday 9am - 5pm EST
Wednesday 9am - 5pm EST
Thursday 9am - 5pm EST
Friday 9am - 5pm EST
Saturday Closed
Sunday Closed
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1 Review

  • 5
    Sundown Audio U6.5 Subwoofer

    Posted by Robert Torres on Nov 01, 2023

    This is the 5th 6.5 inch subwoofer I’ve had and it is by far the best.

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