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Rockford Fosgate Marine M212S4 (White)

12" 4 ohm Marine M2 Series Subwoofer


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Rockford Fosgate PM212S4

OUR PRICE: $349.99

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Rockford Fosgate Marine M212S4 (White)

12" 4 ohm Marine M2 Series Subwoofer


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The RF Marine M2 full-range are perfect for anyone looking to add some real power to their vessel. UV and moisture resistants assure great performance in even the harshest of marine environments.

  • 12" Rockford Fosgate Marine M2 Series Subwoofer
  • Power Handling:
    • Peak: 600 watts
    • RMS: 300 watts
  • Impedance: 4 ohms
  • Injection molded mineral filled parabolic polypropylene cone
  • UV and Salt-Fog resistant TPE (Thermo-Plastic Elastomer) surround
  • High temperature Kapton® former with polyimide insulated copper wire
  • Internal magnetic shielding for reduced electromagnetic interference potential
  • 2" Voice coil
  • Linear, high excursion matched motor magnetics and suspension design
  • Frequency response: 30-250 Hz
  • Sensitivity: 87 dB
  • Color is white
  • Also available in: Black
  • 1-year warranty

Product History:

Rockford Fosgate PM212S4 thumbnail
(newest, current model)
Rockford Fosgate M212S4 thumbnail
(previous model, replaced by Rockford Fosgate PM212S4)

Subwoofer Specifications

Subwoofer Size
Refers to the diameter of the subwoofer, measured in inches.
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.
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
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.
600 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.
300 watts
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.
Thermo-Plastic Elastomer
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.
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
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 - 250 Hz
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.
12 mm
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.
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.

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.
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
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.
Yes - Included
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.
Amplified or Non-Amplified
This indicates if the subwoofer comes with an amplifier installed as one unit or Non-amplified which requires an external amp to power the subwoofer

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


Woodstock, ga

Rockford Fosgate M212S4

July 20, 2011

This sub is underated on its power- It Hits Hard , is Crisp and Clear and is far superior to other 12" Marine Subs out there. Powered by an Alpine pdx 1.600. This thing is a monster.

21 of 25 found this helpful

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evans, CO

Awesome sub!!

August 8, 2012

Looks good and sounds great. Rockford Fosgate subs rock as always.

19 of 22 found this helpful

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Fosgate m2 12" marine sub!! POUNDS!!

September 19, 2013

So impressed. I had installed in 2013 cobalt 200. Baffle. Simply cut /screwed to fiberglass. Use the air from under seats. The whole boat pounds!!! Was going to do 2-12" and 2 amps.... Only did 1 amp and 1 sub and was so good!!

Thx for the amazing deal!

19 of 23 found this helpful

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Browse 4 questions and 4 answers
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Why did you choose this?
Sonic Electronix Store
A friend has the 10" in this model and it ROCKS! I've got 300 RMS on my amp so thought I'd step up to the 12". Can't wait to get it bumpin!
Seth J on May 19, 2015
I'm bridging two amp channels to connect to the sub. Rockford M600 amp diagram indicates connecting amp rear channel to the rear channel on the head unit. My sony head unit also has RCA jacks for a sub. Should I connect to sub jacks or follow diagram and use RCA rear jacks?
Rick B on Aug 1, 2014
Best Answer: The sub jacks on the amp would be my choice.
Reply (1) · Report · gregory q on Aug 2, 2014
· Add Answer · I Have This Question Too (1)
i am thinking about placing this sub in the factory sub location on a 2011 camaro convertible. it would be I Infinet baffle. plan on using a kenwood xr 600 mono amp to power it 600 watts at 2 olms. how do you think this will perform? i want to both hear and feel the base. also would be a 10 in model.
Mark S on Jul 9, 2015
Best Answer: I went through 2, 12" models blew each probably due to the fact that there is really no such thing as a free air/infinite baffle sub. I also may have overpowered them. With a JL 600 mono cranked up! But the sub itself was so impressive I will probably order yet a 3rd and adjust my gain. All of my friends and I rocked out for the greater part of a summer with one, then the other on a boat and everyone was blown away with how hard this sub hit! I mean this baby slammed! Priceless summertime fun!
Reply (1) · Report · Justin M on Jul 9, 2015
· Add Answer · I Have This Question Too (0)
What is the actual dimension of the cut out hole and the outside grill?
Mark H on Mar 22, 2015
Best Answer: Hello Mark,

Page 4 of the manual, link below, has all the available dimensions:
Reply · Report · Customer SStaff on Mar 23, 2015
· Add Answer · I Have This Question Too (0)

Product Summary


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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: Rockford Fosgate Marine M212S4 (White)