MS 12SD4 Refurbished



25 – 1800 watts suggested amplifier power range

JBL engineers designed the MS-12SD4 premium subwoofer to produce thundering, forceful bass from an amplifier capable of delivering up to 1800 watts of power. The MS-A5001 digital signal-processing amplifier, part of the JBL MS Series, is an ideal power partner for the MS-12SD4.


Rigid polypropylene cone

The MS-12SD4 subwoofer features a rigid polypropylene cone that is lightweight but stiff enough to move air effectively without flexing. The result is a low-frequency diaphragm that reduces unwanted mechanical distortion under movements up to its linear-excursion (Xmax) limits.


Stitched tri-laminate surround

The stitched tri-laminate surround on the MS-12SD4 subwoofer features dual stitch lines for a robust connection to the cone. The material is uniquely able to control the cone’s movement and dampen any vibrations that originate in the frame and mounting surface from reaching the cone. The result is precise control and excellent bass at low or high volumes.


Cast-aluminium frame

The cast-aluminium frame on the MS-12SD4 subwoofer ensures a rigid chassis for the sub’s moving parts. Since cast aluminium is nonmagnetic, the sub’s magnetism is focused on the voice coils to control the cone’s rapid, piston-like movement and reproduce even the most complex bass sounds faithfully. Cast aluminium also dissipates heat efficiently and hence provides reliable power handling.


Vented magnet assembly

All MS-12SD4 subwoofers include a vented magnet assembly to let the voice coils breathe. This feature reduces the probability of power compression in systems playing loudly over a long period. It means an efficient use of amplifier power so that all the power delivered to the subwoofer is directed to the voice coil and not wasted as residual heat.


Flexible, dual voice-coil design

Dual voice coils on MS-12SD4 subwoofers offer the best range of wiring and system-configuration options to optimize the amplifier’s output load. When you’re using multiple subwoofers, the dual voice-coil configurations allow dual, triple and even quad subwoofer designs to optimize the amplifier load for maximum power output.


Small sealed and vented enclosure volumes

MS Series subwoofers provide amazing bass from modest enclosure volumes. For this 12-inch (300-millimetre) sub, we recommend a respectable 0.95 cubic feet (about 27,100 cubic centimetres) sealed enclosure or 1.7 cubic feet (about 48,100 cubic centimetres) vented enclosure. Since vented enclosures provide greater output than sealed enclosures given the same power, the vented-enclosure option will work with smaller amplifiers.


Spring-loaded connection terminals

The MS-12SD4 subwoofer features spring-loaded connection terminals for both voice coils, ensuring ease of connection for a variety of wire-gauge sizes. The subwoofer’s push terminal also makes easy work of connecting series or parallel voice coils, or wiring to other subwoofers.


Match with other JBL MS Series products

The JBL MS-A5001 digital signal processing mono amplifier is an ideal companion to one or more MS-12SD4 subwoofers. Add an MS-8 digital integration processor to the sound system, and listen to the speakers come alive, blend seamlessly with the sub and provide an in-vehicle sound experience that’ll rival great home audio experiences. JBL engineering has once again delivered excellence in an MS Series product.

Specs & Downloads

Item# MS-12SD4


Premium-performance 4-ohm subwoofer.

The JBL® MS-12SD4 is a high-performance, high power-handling, dual voice-coil subwoofer using advanced materials and innovative engineering to create smooth, powerful bass in your car. The subwoofer’s dual 4-ohm voice-coil design allows for a wide variety of connection options. You can use multiple subs to add bass, as many amplifiers – particularly the JBL MS-A5001 digital signal processing amplifier – easily drive multiple subwoofers. This sub features advanced components that include rigid polypropylene cones, stitched tri-laminate surrounds, vented magnet assemblies and non-magnetic, cast-aluminium frames for minimal power compression under extended use. Its peak power handling is 1800 watts, so it can handle tremendous power. It requires very modest enclosure volumes and performs well in either a sealed or a vented enclosure design. This subwoofer is truly a premium, performance-oriented product that can deliver excellent bass in your car.

General Specifications

$239.95 each

Audio Specifications

(1W @ 1m) 87dB SPL
Peak Power
Power Handling (RMS)
Power Handling (Peak)
Frequency Response
(-10dB) 30Hz-400Hz
Nominal Impedance
4+4 ohms


Mounting Cutout Diameter (in)
External Diameter (mm)
Mounting Depth (mm)
Weight (lb)
Weight (kg)
External Diameter (in)
Mounting Depth (in)
Mounting Cutout Diameter (mm)

What's in The Box?

  • 1 MS-12SD4 subwoofer
  • Owner’s manual
What's in The Box?

Documents & Downloads

Reviews and Q&A

Customer Reviews

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Product Q&A

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