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U-Series v.2 18
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U-Series v.2 18
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U-Series v.2 18
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U-Series v.2 18

U-Series v.2 18" Subwoofer

Regular price $719.99 USD
Regular price Sale price $719.99 USD
Shipping calculated at checkout.

Notice On Packaging For Subwoofers
Sundown Audio has led the industry in quality and performance for over a decade. To improve accuracy and transparency, we have updated our subwoofer power ratings to reflect true real-world performance.
During this transition, some packaging may show previous ratings. Performance fully aligns with our current published specifications. If you have any questions about authenticity or ratings, please contact directly for confirmation.

Impedance: D4
    • 2000 Watts RMS / 4000 Watts Peak
    • Dual 2 or 4 ohm voice coils
    • Optimized for small ported or bandpass enclosures
    • Aluminum 3” voice coil former for superior heat dissipation
    • High-temperature copper voice coil
    • Double stitched surround
    • Heavy-duty cast basket
    • Spring-loaded terminals accept up to 8-gauge wire
    • Stitched-on heavy-duty tinsel leads
    • Solid pole with vent channels and aluminum shorting ring cap
    • Rear gap-venting
    • Top-Plate Cooling Channels

    Designed to be at home in the competition lanes or playing your favorite music, the U Series is the premier “standard suspension” woofer in the Sundown lineup. A double-stacked 9.4-inch wide ferrite magnet system is coupled to a thick top plate. A thick set of shorting rings are used inside the magnets and on the pole cap, smoothing out frequency response while doubling as a heat sink and airflow guide. A custom aluminum frame was designed specifically for the U Series. It’s substantially thicker and equipped with heat dissipation ribs at the bottom of the frame. The U v.2 motor also features an extended pole piece to keep the coil under perfect control under high stress. The coil temperature is controlled with machined, high-velocity pole channels and a series of 16 direct air-gap vents in the back plate.


    Dimensions

    ParameterD2 ModelD4 Model
    Re3.87 Ω6.07 Ω
    Fs30.9 Hz30.9 Hz
    Qms5.63005.5100
    Qes0.56600.6500
    Qts0.51000.5800
    Vas111.760 L114.690 L
    Mms565.41 g552.15 g
    Cms0.05 mm/N0.05 mm/N
    BL27.402 T·m31.490 T·m
    Le3.39 mH4.74 mH
    Sd1641.9 cm²1641.9 cm²
    Xmax30mm30mm
    SPL (1W/1m)92.6 dB90.0 dB
    SpecificationD2 ModelD4 Model
    RMS Power2000 W2000 W
    Peak Power4000 W4000 W
    Displacement.26cu ft.26cu ft
    Mounting Depth10"10"
    Outside Diameter18.63"18.63"
    Cutout Diameter16.9"16.9"
    Motor Diameter9.7"9.7"
    Sealed Enclosure3.0cu ft3.0cu ft
    Ported Enclosure4.0cu ft4.0cu ft
    Recommended Port Tuning35hz35hz
    Recommended Port Area64sq in64sq in
    Xmax30mm30mm
    4th Order Sealed2.25cu ft2.25cu ft
    4th Order Ported6.75cu ft6.75cu ft
    4th Order Port Area135sq in135sq in
    4th Order Port Length6"6"

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