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Rockville W12K9D4 12 inches 4000w Car Audio Subwoofer Dual 4-Ohm Sub CEA Compliant

W12K9D4 OB
$249.00 $102.67
(You save $146.33)

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Warranty Information:


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 Features of W12K9D4:

  • Rockville W12K9D4 K9 Series 12" Dual 4-Ohm Car Subwoofer
  • Peak Power Handling: 4000 Watts
  • Program Power Handling: 2000 Watts   
  • CEA Rated RMS Power Handling: 1000 Watts 
  • 3" 4-Layer Black Aluminum Voice Coils Wound with OFC Wire Made in USA
  • This voice coil is stable up to 240 degrees celcius! The voice coil windings are made in the USA!
  • Double Stacked 190 Oz High Quality Magnet
  • Cast Aluminum Basket With Black Sanded Finish Makes This Sub Very Efficient And Lighter Weight
  • Two Chrome-Plated Binding Post Terminals
  • Black Non-Pressed Paper Cone With Beautiful Finish
  • Our cones are ultra-stiff. They are thicker and stronger than other subs on the market making our subs able to handle more power.
  • Thick Foam Surround Provides Incredible Sound Quality With Minimal Distortion
  • Red Stitching Cone Reinforcement Ensures Long Life
  • New Ultra-stiff  PolyPropylene (PP) Dustcap
  • Impedance: Dual 4-Ohm Voice Coils
  • Vented Hole on T-yoke Enhances Heat Dissipation
  • Special Custom Rubber Boot Magnet Covers Make the Woofer Look Nice and Protects the Magnet
  • Custom Rockville Mounting Gasket Looks Beautiful and Makes it Easy To Mount the Subwoofer Air-Tight
  • High BL Magnetic Motor Gap
  • We use the highest grade black glue that handles extremely high temperatures which allows our woofer to handle even more power than they are rated
  • Nomex Spider provides tear resistance, strength and long-term reliability over regular cotton and poly cotton spiders
  • Cutout Diameter: 11.13” inches
  • Mounting Depth: 6.85” inches
  • Frequency Response: 33 Hz - 1.5K kHz
  • 10mm T-Yoke + 10mm Washer
  • Sensitivity: 83dB
  • Sealed Enclosure Volume: 0.9 – 1.47 Cubic Feet
  • Vented/Ported Enclosure Volume: 1.8 – 2.75 Cubic Feet
  • XMAX is 28MM
  • Weight: 28.67 Lbs.
  • Shipping Weight: 33 Lbs.
  • Shipping Box Dimensions: 14.57" x 14.57" x 10.83" Inches

Detailed Info:

  • Body: Non-Pressed Paper
  • Gap Plate Inside Diameter: 95mm (3.74 inches)
  • Gap Plate Outside Diameter: 190mm (7.5 inches)
  • Gap Plate Thickness: 25mm (1 inch)
  • Yoke Outside Diameter: 180mm (7.1 inches)
  • Yoke Thickness: 10mm (0.4 inches)
  • Yoke Pole Diameter: 75mm (3 inches)

TS Parameters:

TS Parameter

Wired in Series

Description of Measurement

Electrical Parameters


8 Ohm

Electrical voice coil resistance at DC


5.29 mH

Frequency independent part of voice coil inductance


99.5 Ohm

Resistance due to mechanical losses


31.7 Hz

Drive resonance frequency

Mechanical Parameters


271.8 g

Mechanical mass of drive diaphragm assembly including air load and voice coil


9.7 kg/s

Mechanical resistance of total-drive losses


0.09 mm/N

Mechanical compliance of drive suspension


28.2 N/A

Force factor (Bl product)

Loss Factors



Mechanical Q-factor of of drive in free air considering Rms only



Electrical Q-factor of drive in free air considering Re only



Total Q-factor considering Re and Rms only

Other Parameters


38.9 l

Equivalent air volume of suspension



Diaphragm area


  • UPC:
  • 613815622086

WARNING: Cancer and Reproductive Harm —

Car Subwoofer Impedance Wiring Guide

Use our car subwoofer and amp wiring diagrams to figure out which amplifier is compatible with your subwoofer(s) and how to wire it properly.

New orders ship within 1 business day
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