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MB Quart RLP-304

300W 12" Reference Series Dual 4 ohm Low-Profile Subwoofer

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List price $169.99

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MB Quart RLP-304



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Atrend 12TK


Special Price $34.46 ($45.95 if purchased separately)

Atrend 12TK

12" Single Universal Truck Style Sealed Subwoofer Enclosure • Premium carpeted Finish • Silver Spring Loaded Terminal Cups • Completely Miter and Dado Panels • Glued and Braced with Fasteners

(Offer 1 of 1)

Combined Total Price


You Save $11.49

  • 12" Dual 4 Ohm Reference Series Shallow Mount Subwoofer
  • Power Handling:
    • Peak: 600 watts
    • RMS: 300 watts
  • Impedance: Dual 4 Ohm
  • Injection molded polypropylene cone woofer
  • Foam surround
  • Shallow mount for small and compact installations
  • Recommended use in sealed enclosures
  • Dual voice coils
  • Frequency response: 25-160 Hz
  • Sensitivity: 86 dB
  • 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.
Reference Low Profile (MB Quart)
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.
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
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
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).
25 - 160 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".
86 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.
9 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.
Injection Molded Polypropylene (IMPP)
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.
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.

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.
0.5 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.
0.75 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.


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


Boiling Springs SC

MB Quart RLP 304

January 16, 2012

Great sound, excellent speakers.

21 of 35 found this helpful

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Big Wash

Washington D.C.

Great space saver and gets the job done!

July 19, 2012

This subwoofer is the best if you don't have a lot space. Rich deep bass and can handle a good amount of power!

20 of 35 found this helpful

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Solid Product and Great Base

January 25, 2011

I wanted a slimline sub with some kick to fit behind the seat of my Boxster. This was one of the few that would fit. It has been thumping hard ever since i installed it.

18 of 32 found this helpful

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Lansing, MI

Shallow Mount, not shallow sound

September 17, 2013

Great driver. DVC is wired at 2 ohms, and pushing 300W to it. Made a custom box @ 0.45 cu ft. (interior volume) stuffed with polyfill per MB Quart's recommendation. For a 12 inch shallow that mounts under my passenger seat, it does a fine job on its own. Solid lows, no fatigue in sound and punchy kick drums. Bass guitars sound like bass guitars, not boomy nonsense.

Does it shake my neighbor's house? Only if I'm parked next to it, but that doesn't change the insanity inside my car's cabin that it can create without distortion/clipping. Great addition to my system.

19 of 35 found this helpful

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small box - big sound

July 31, 2013

This sub is designed to work in a small closed box and comes through with flying colors! I needed a small box for my boat and did not want to go smaller than 12" . I had a 3/4cuft box made for the sub. Stuffed the box with fiber and had the outside bedlinered.
Sub sounds great!

18 of 33 found this helpful

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Omaha, NE

These subs bump!!

September 24, 2013

I ordered 4 of these 12in mb quarts which will be going in my 2008 dodge ram pick up. These subs bump, have them wired at 2ohms at 400watts. Surprisingly the hit lows pretty good and the high notes sound awesome. Definitely worth the money and sound better then the alpine type r's I had in my truck. FOR THE LOW PRICE YOU MIGHT AS WELL TRY THEM!

19 of 36 found this helpful

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Clarksville, AR

Great Shallow mount!!

May 5, 2012

This product is GREAT. I have a SINGLE cab '87 Ford Ranger, custom built box and it fits. The box has bout .7cu ft and i have it wired at 2 ohms, pushing 550 watts to it. This subwoofer SLAMS. People are amazed by how loud it is, especially for ONE 12in SHALLOW mount. I hit the lows very easily and the highs will impress you. A very good unit to purchase!!

20 of 38 found this helpful

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Jeff G


I love these subs!

September 29, 2011

I have an extended cab F-250. As some are probably aware, there isn't a ton of room in these trucks.

I built a box to MB Quart's spec..... and these subs do not disappoint in small sealed boxes.

19 of 36 found this helpful

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Coeur d'Alene, ID.


September 23, 2013

I was looking for a quality system at a reasonable price. I kept all components MB and they sound awesome.

With MB-Quart I was able to achieve this!

Thank you.

I do recommend.

18 of 36 found this helpful

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Elizabeth, NJ

Good sound for the $$$

October 14, 2011

Quality, price, are the reason I recommend this product. Looks good too.

17 of 34 found this helpful

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porterville ca

Love it!

November 1, 2011

I just recently bought one to fit hidden away in my supercab truck and the sound was great! I have put alot of speaker components in and this sub was great! Rich clean bass!

15 of 31 found this helpful

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Houston, TX

Good value but not the best of speakers

December 31, 2009

Having the volume air space to fit subs in my truck is a big problem. I custom built the largest sealed enclosure that I could possibly stuff under the back seat and got 0.68 cu. ft. This subwoofer's specs lined up exactly with what I needed and the price is right. I purchased the DVC 2ohm version.

Qualtiy of Construction:
I am not impressed with the materials and quality of the subwoofer but it is not terrible. There was nothing wrong with it but it just feels cheap. I suppose that is why it is so inexpensive.

The subwoofer's cone really has to be moving for much sound to be generated. The speaker must be driven hard and it really never gets as loud as it should. Perhaps that is a product of its design for small enclosures at the fact it is a shallow mount type. So, it is better than nothing, but it does not compare to a real, deep mounted 12" subwoofer in low frequency tones.

Buy again?
Maybe but probably not. There really is not another choice with the same features that I could find. I was looking for a shallow mount, DVC, 2 ohm, 12" sub that worked with a tiny box and this is pretty much the only one that I could find for a reasonable cost.

14 of 30 found this helpful

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MB Quart wins

April 4, 2011

This is a really great sub that fit my purpose exactly. Its an awesome unit that delivers punchy bass, has a great look yet slim enough to be easily hidden.

15 of 33 found this helpful

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Accessory Tools and Products

Accessories added

Single 12" Subwoofer Angled Truck or Hatchback Box Enclosure

CARB Compliant, 5/8" MDF Shallow Sub Enclosure Lined with Polyfil.

Your Price $29.99

NVX 25 ft. of True Spec 12 Gauge Speaker Wire

100% OFC wire with EnvyFlex metallic jacket insulates and protects against damage from extreme conditions.

Your Price $39.99

25 ft. of Streetwires 12 Gauge Speaker Cable

You'll need speaker wire to hook up that new subwoofer!

Your Price $44.95

Belva 23 ft. of 12 Gauge Speaker Wire

Ultra-flexible PVC blended jacket for easy installation.

Your Price $14.99

20 Square Feet of Sound Dampening Material

NVX Sound dampening is thicker than competitors, eliminates rattles and gives you bigger bass!

Your Price $59.99

Dynamat Sound Dampening Trunk Kit

Did you know sound dampening will reduce those annoying rattles and even increase your SPL?

Your Price $94.95

Stinger Sound Dampening Trunk Kit

Stinger's Roadkill sound dampening series is sure to kill unwanted road noise and rattles! Enough sound dampening for your whole trunk!

Your Price $69.99

12 oz. Can of Adhesive Spray

Spray adhesive used for adhering carpet to subwoofer boxes without bubbles.

Your Price $6.99

Gold Plated Dual Terminal Banana Plug Connector

Enables an expandable, secure connection accepting up to 8 gauge wire.

Your Price $1.99

2" Universal, Professional Heavy Duty Roller for Sound Damping/Dampening

Universal rubber roller to make it easy to install sound dampening.

Your Price $7.99

Car Stereo and Speaker Installation Tool Kit

Includes Test Light, Crimp/Splice Tool, Multi-bit Screwdriver and more.

Your Price $16.99

Xscorpion 9-Piece Nylon Plastic Pry and Chisel Tool Set

Easily removes dash/trims, door clips, panels and pins, rubber grommets and vehicle emblems.

Your Price $14.99

Cordless Multi-Functional Heat Tool Soldering Iron Kit

Continuous working lock allows you to work without holding down trigger.

Your Price $79.99

4 Ft of 1/4" Thick Black Heat Shrink Tubing

Provides abrasion resistance and added protection for your cables.

Your Price $3.99

1mm All Purpose Solder

Solder is all purpose for use on most projects where solder is needed.

Your Price $8.99

Universal 12" Subwoofer Grille

Keep your subwoofer safe from accidental damages with this amazing grill.

Your Price $19.95

12" Protective Waffle Subwoofer Grille

Keep your subwoofer looking amazing while keeping it safe.

Your Price $4.99

Scosche SPL Meter

Monitor the noise level of your new car audio system with this SPL meter measuring from 60-135 dB.

Your Price $21.99

1 MB Quart RLP-304 Subwoofer

Mono Amp

2 Channel Amp - Bridged

2 MB Quart RLP-304 Subwoofers

Mono Amp

Mono Amp - Option 1

2 Channel Amp

2 Channel Amp - Bridged

4 Channel Amp - Bridged

3 MB Quart RLP-304 Subwoofers

Mono Amp

4 Channel Amp

4 MB Quart RLP-304 Subwoofers

Mono Amp

2 Channel Amp

2 Channel Amp - Bridged

4 Channel Amp

Items we think you might want
RLP-304-PAIR thumbnail
MB Quart RLP-304 Subwoofer Pair Combo

• 1200W Peak
• 600W RMS
• Injection Molded Polypropylene Cone
• Foam Surround
• Recommended for Sealed Enclosures

Your Price $246.94

Browse 1 question and 2 answers
Hide answersShow all answers | Sort by
what speaker grills are used for this speaker ?
A shopper on Aug 6, 2014
Best Answer: i am not going to use a speaker grill on this install but I have in the past on high excursion subs. i did find that a high quality, solid grill is useful if there is a possibility of something getting in contact with the face of the woofer. Just as a reference I used a closed face grill on an Alpine Type-X 12 inch pushing 2000 watts to it with no problems. Just make sure it fits about 1/2 inch atleast from the woofer face.
Reply · Report · Jamie G on Aug 7, 2014
· Add Answer · I Have This Question Too (0)

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: MB Quart RLP-304

  • MB Quart Dual 4 Ohm Low-Profile Reference Series Subwoofers
  • MB Quart RLP Shallow Mount Subwoofers
  • Subwoofer Size Buying Guide