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450W 12" MS Series Dual 4 ohm Subwoofer


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The New Sound of JBL: MS Series Subwoofers

JBL MS-12SD4 Subwoofer JBL MS-12SD4 Subwoofer Cone

The Cone

No sound system is complete without some seriously deep bass. The hard hitting 12" JBL MS-12SD4 subwoofer provides just that. The dual voice coils allow for greater flexibility and more wiring options.

  • Lightweight polypropylene cone
  • Double stitched laminated polyurethane and fabric surround
  • Peak power handling: 1800 watts
  • RMS power handing: 450 watts
  • JBL MS-12SD4 Subwoofer Connections

    The Details Matter

    JBL has carefully engineered and constructed the MS-12DS4 from the ground up to ensure use for years to come. The durable, light weight aluminum basket is nonferrous, which dedicates more magnetic power to the motor assembly.

  • 56 oz. Barium ferrit magnet structure
  • Silver-plated push terminals
  • Stitched tensil weaves
  • Vented pole piece
  • General Features

    • 12" Dual 4 ohm MS Series Subwoofer
    • Power Handling:
      • Peak: 1800 watts
      • RMS: 450 watts*
    • Impedance: Dual 4 ohm
    • Polypropylene cone material
    • Laminated polyurethane and fabric surround
    • Vented pole piece
    • Designed for both sealed and vented enclosures
    • Aluminum frame with black epoxy coating
    • 2-1/2" Copper voice coil with Kapton former
    • 56 oz. Barium ferrit magnet structure
    • Silver-plated push terminals
    • Frequency response: 30-400 Hz
    • Sensitivity: 87 dB
    • Authorized Internet Dealer
    • 1-year Manufacturer's warranty

    Subwoofer Specifications

    Subwoofer Series
    Each subwoofer manufactured is part of a series. This is the name of the subwoofer's series.
    MS (JBL)
    Subwoofer Size
    Refers to the diameter of the subwoofer, measured in inches.
    Peak Power Handling
    Peak power handling refers to the amount of power a speaker can handle during a brief musical burst. The RMS power range figure is a much more reliable rating for determining the speaker's power requirements. The Peak power handling specification is typically rated per speaker unless otherwise noted.
    1800 watts
    RMS Power Handling
    The RMS power is the amount of power the speaker requires to operate safely and properly. RMS Power Handling refers to the amount of power a speaker can handle on a continuous basis. We recommend powering your speakers or subwoofer with 80%-120% of its recommended RMS rating. The RMS power handling specification is typically rated per speaker unless otherwise noted.
    450 watts
    Voice Coil(s)
    Dual voice coil subs have more wiring flexibility than single voice coils subs; however, single voice coil subwoofers provide easier hookup options for wiring multiple subwoofers in parallel or series. You may also run a dual voice coil (DVC) sub in parallel, series, or combination. A quad voice coil has four voice coils and is equal to two dual voice coil subwoofers as far as wiring goes.
    Impedance (Per Voice Coil)
    The load value (in ohms) that the speakers present to the amplifier per voice coil - the amount of resistance to the current flow. This is a key specification as subs wired in parallel or low impedances can create problems with your amplifier and potentially void all warranties. We encourage you to ask our support department prior to purchase if you do not understand which impedance level will suit your application best.
    4 ohms
    Voice Coil Diameter
    Diameter of voice coil, usually measured in inches.
    Frequency Response
    The range of frequencies the speaker will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
    30 - 400 Hz
    An efficiency or sensitivity rating tells you how effectively a speaker converts power into sound. The higher the number, the more efficient the speaker and the louder it will play with the same input power. An efficient speaker helps you maximize your available power. Most sensitivity ratings measure the speaker's output with 1 watt of input, 1 meter from the speaker. Some speakers' sensitivity is measured with 2.83 volts of input, instead of 1 watt.
    Efficiency (1w/1m) is not an accurate indicator of a subwoofer's output capability and should not be used as a comparison to other speakers or subwoofers to determine which one is "louder".
    87 dB
    Xmax (millimeters)
    Typically measured in millimeters, the Xmax value is the measure of a speaker cone's maximum excursion in one direction while maintaining a linear behavior.
    7 mm
    Subwoofer Design
    This is the design of the subwoofer or the opening of the subwoofer enclosure. Each design has it's own benefits, whether it is a square, circle, or oval.

    Round/Circle: This is the typical and common subwoofer design. They have a round cone and are a circle in design.

    Square: These woofers are able to achieve a greater cone area in a smaller space. Because of the greater surface area, some square subwoofers will be louder than a round subwoofer of the same size.

    Round / Circle
    Main Cone Color
    This is the color of the speaker's or subwoofer's cone.
    Woofer Composition
    Lightweight woofer cone materials are essential for efficient operation. Poly cones produce exceptional sound and are sturdy against various changes in temperature. Paper cones are very efficient, and when treated for moisture resistance, will perform at a high level. Poly refers to polypropylene, which is thermoplastic or fibers that are polymers of propylene. IMPP refers to injection molded polypropylene, a commonly used process and material in speakers.
    Woofer Surround
    A speakers surround is part of the suspension system. The surround protects the cone and prevents it from being displaced as it flexes out from the basket. It is usually made of a durable material like treated foam or rubber in order to withstand the strenuous job of producing bass frequencies.
    Poly Coated Cloth
    Magnet Structure
    Defines the overall structure of the subwoofers magnet.
    Single Stacked
    Subwoofer Grille
    Most subwoofers are able to accommodate a universal grille; however, some subs include a grille and others have a specific, optional grille available for purchase separately. If "yes", then the subwoofer includes a grille. If "optional (sold separately)" the matching grille will need to be purchased in addition to the sub.
    Re-Cone Kit Available
    Some higher end subwoofers have replaceable cone assemblies. In case of a blown woofer, a recone kit allows for a simple replacement, as opposed to purchasing an entire new subwoofer.

    Recommended Enclosure Specifications

    Recommended Enclosure Type
    This is the recommended type of enclosure that the subwoofer should be installed into. Some subwoofers are specially designed for particular enclosures.

    Sealed: These enclosures completely enclose the air inside the box. These boxes produce a tight bass.

    Ported/Vented: These enclosures have a slot of air to escape from the box. The result is a sound that has more "boom".

    Bandpass: These are a combination of both sealed and ported enclosures. They can be very efficient, but require tuning for the best response.

    Ported / Vented
    Minimum Sealed Box Volume
    This value indicates the minimum sealed box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
    0.95 cubic feet
    Maximum Sealed Box Volume
    This value indicates the maximum sealed box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
    0.95 cubic feet
    Minimum Ported Box Volume
    This value indicates the minimum ported box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
    1.7 cubic feet
    Maximum Ported Box Volume
    This value indicates the maximum ported box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
    1.7 cubic feet
    Top-Mount Depth
    The depth when installed on top of the mounting surface. Measured from the bottom of the speaker's magnet to the bottom of the mounting holes on the rim of the speaker.
    Cutout Diameter
    The actual diameter of the hole you will need to cut out if you are creating a new mounting location for this speaker, or if you are mounting a subwoofer in a box.
    Shallow Mount Installation
    This means that the subwoofer/speaker is designed to be installed in areas that do not have a lot of space. Shallow mount subwoofers are typically found under a seat or behind the seat in some trucks.

    Shallow mount speakers will typically have a mounting depth of 2" or less, while shallow mount subwoofers will typically have a mounting depth of 3" or less.


    Electromechanical Parameters

    Free-Air Resonance (Fs)
    The free-air resonance frequency of the subwoofer, measured in Hz. At this frequency the weight of the moving parts is perfectly balanced with the subwoofers suspension system.
    37 Hz
    Equivalent Compliance (Vas)
    This is the amount of air that has the same stiffness as the subwoofers suspension. The greater the rating, the lower the stiffness and larger recommended enclosure. It is measured in Liters.
    47 liters
    Total Speaker Q Value (Qts)
    This is the subwoofers relative damping (Q) at the resonance frequency (Fs), including all dimensionless losses. Essentially, a high Qts value (closer to 1.0) means the subwoofer is great for sealed enclosures and a low Qts value (closer to 0) means the woofer is great in vented enclosures. A Qts of around 0.45 means the woofer will work decently in either enclosure type.
    Electrical Q Value (Qes)
    The subwoofers relative damping (Q) at the resonance frequency (Fs), including electrical losses. Also called the mechanical damping of the subwoofer. The unitless measurement usually varies from 0.5 10.
    Electrical Resistance of Voice Coil (Re)
    Amount of DC resistance of the subwoofer when measured with an ohm meter. Typically, this will read less than the impedance rating of the subwoofer.
    7.7 ohms
    Mechanical Q Value (Qms)
    This is the subwoofers relative damping (Q) at the resonance frequency (Fs), including mechanical losses. Also called the mechanical damping of the subwoofer. This unitless measurement usually varies from 0.5 10.

    Specials with this Item

    Promotions we have offer More Ways to Shop for items that are on clearance, last chance, special offer and sales, Made in America, and more!
    On Sale

    Warranty and Return Policy

    Parts Warranty Duration
    1 year
    Labor Warranty Duration
    1 year
    Warranty Provider

    Summary of Customer Ratings & Reviews

    Rating Distribution

    5 Star
    4 Star
    3 Star
    2 Star
    1 Star

    Average Attribution Rating


    St. Cloud, FL


    March 18, 2012

    I just bought two of these subs to replace my 10 year old Infinity Reference 12" subs. One of them came unglued from the surround. I was originally just going to get two more of the newer Infinitys but after reading that it was a common problem, I decided to pick up the JBLs to keep it in the Harmon family. Let me start by saying that I have professionally installed car audio for over 5 years. While these are no Gti, they definitely pound. For the price they can't be beat. These are great subs that get low in a very small enclosure. I currently have them in a .85 cubic foot fiberglass enclosure that were originally made for the Infinity subs. They sound so much better than the infinity subs and I haven't had the chance to retune the system to accommodate the new JBLs. Sonic did a great job with the emails and tracking info and the package came in exactly when they said. Overall I am extremely happy with the product and the service. Great job Sonic Electronix. I will definitely be shopping here again.

    1 of 1 found this helpful

    Help our customers find the most helpful reviews


    Cincinnati, OH

    Great Sub

    March 3, 2013

    Hits pretty hard. I have had it for about a year and no troubles. Con's: I don't particularly like the chrome "JBL" emblem, but I can live with it.

    0 of 0 found this helpful

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    Awesome Sub - Great Price

    March 11, 2012

    Me: 25, professional, college graduate, musician I listen to a variety of music (not just bass crazy rap or electro.) JBL has never let me down with any products - from my loudspeaker monitors and surround speakers to my father's huge old school set from the '70's that still sound amazing - JBL is all about precision performance with durability. I put this speaker in the sealed 1.0cf sonic sub box, running at 2ohms 1000+w rms Kicker DX1000.1. It sounds so good, and it's not even broken in yet! (less than 5hr playing time). It replaced an older Kicker L5 in a huge ported box. I wasn't happy with the sound from the L5 setup. Sloppy bass with music that had quick beats, and the frequency sweet spot was just overbearing and hard to tune from amp/head unit. I like deep, accurate and punchy bass and this sub has so far delivered more than even my expectations. Right out of the box I can tell this is a better sounding sub than the Kicker, and it takes up half the space! The sub isn't flashy with flames, crazy grill design, bright colors or chrome. It's a minimal design that looks clean and unassuming, but I can tell that it is built very well and it can hit LOW and keep up with fast punches in the trunk of my Maxima. Yes, you might get something that's louder with a 50lb magnet and shake your car to pieces. But you'll probably lose SQ unless you spend 3x the $ or more. I got my sub and box for a great price and I get a grin every time the bass drops. Thanks Sonicelectronix for hooking me up so well with all my purchases!

    0 of 0 found this helpful

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    Product Summary


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    Internal SKU


    Internal Product ID


    Sonic Electronix Wiring Guide

    Wiring Diagram Legend

    Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

    Product Name: JBL MS-12SD4

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