RWM254 - Subwoofer MB QUART - Free user manual and instructions

Product Type	Subwoofer
Brand	MB Quart
Model	RWM254
Woofer Size	12 inches (30.5 cm)
Impedance	4 ohms
RMS Power Handling	300 watts
Peak Power Handling	600 watts
Sensitivity	88 dB (1W/1m)
Frequency Response	25 Hz - 200 Hz
Recommended Enclosure	Sealed or ported (1.0-1.5 cu ft sealed, 1.5-2.0 cu ft ported)
Mounting Depth	6.5 inches (16.5 cm)
Cutout Diameter	11.1 inches (28.2 cm)
Magnet Weight	80 oz
Voice Coil	Dual 2-ohm or dual 4-ohm (check model variation)
Cone Material	Polypropylene with rubber surround
Low Pass Filter	Built-in (variable, 50-200 Hz)
Phase Control	0/180 degrees
Power Connection	Speaker terminals (gold-plated)
Weight	12 lbs (5.4 kg)
Recommended Amplifier Power	250-500 watts RMS at 4 ohms
Warranty	1 year limited
Installation Notes	Ensure proper enclosure ventilation and secure mounting

Frequently Asked Questions - RWM254 MB QUART

What is the optimal enclosure type for the MB Quart RWM254?

The RWM254 performs well in both sealed and ported enclosures. For a sealed box, use 1.0 to 1.5 cubic feet; for ported, use 1.5 to 2.0 cubic feet with a tuning frequency around 35 Hz.

What is the RMS power handling of this subwoofer?

The MB Quart RWM254 has an RMS power handling of 300 watts and a peak power handling of 600 watts.

What impedance options are available for the RWM254?

This subwoofer is available in dual 2-ohm or dual 4-ohm voice coil configurations. The standard model is 4 ohms, but verify the specific variant.

Can I use this subwoofer in a home theater system?

Yes, the RWM254 can be used in home theater systems with an appropriate amplifier and enclosure, but it is designed primarily for automotive use.

What is the recommended amplifier power for the RWM254?

An amplifier delivering 250 to 500 watts RMS at 4 ohms is recommended for optimal performance.

Does the subwoofer come with a grille?

No, the RWM254 is typically sold as a bare subwoofer. Grilles may be purchased separately if needed.

What is the mounting depth and cutout diameter?

Mounting depth is 6.5 inches (16.5 cm), and the cutout diameter is 11.1 inches (28.2 cm).

How do I break in the subwoofer properly?

Play the subwoofer at moderate volume (50% of RMS power) for 10-12 hours with a variety of bass-heavy music. This allows the suspension to loosen and achieve full excursion.

What is the sensitivity rating?

Sensitivity is 88 dB per 1 watt at 1 meter, making it moderately efficient.

Does the RWM254 have a built-in low-pass filter?

Yes, it features a variable low-pass filter (50-200 Hz) and a 0/180-degree phase switch for integration with full-range speakers.

USER MANUAL RWM254 MB QUART

Thank you for choosing the MB Quart REFERENCE subwoofer for your car audio sound system. With proper installation, you are on the path to experiencing your music in a way you only imagined possible. Here at MB Quart, we call this “Sound In Every Detail.”

The REFERENCE series subwoofers have been designed for the enthusiast looking for accurate bass and solid reliability in their woofer. The REFERENCE series subwoofers feature the following:

• Injection Molded Polypropylene Cone
• UV Resistant Butyl Rubber Surround
• 2" High Temp Voice Coil

• Red Nomex Spider

• Push & Insert Style Speaker Terminals

• Deep Drawn Stamp Steel Basket
• Heat-Dispersing Vented Pole Plate
• Anti-Resonant Magnet Cover

Close-up of a black speaker with visible sound waves and mounting feet (no text or symbols)

Index

RWM252 - Technical Data	2
RWM254 - Technical Data	3
RWM302 - Technical Data	4
RWM304 - Technical Data	5
WIRING DIAGRAMS - DVC 2-Ohm Models	6
WIRING DIAGRAMS - DVC 4-Ohm Models	7
THIELE SMALL PARAMETERS & BOX DESIGNS	8
SUBWOOFER INSTALLATION DIRECTIONS	9
GLOSSARY OF TERMS	10

TECHNICAL DATA

Power Rating:	350-700 W
Impedance:	DVC 2 ohms
Sensitivity:	83.3 dB (1W/1m)
Frequency Response:	30-250 Hz
COMPRISING:
1 woofer	25.4 cm / 10"

DATOS TÉCNICOS

TECHNICAL DATA

Power Rating:	350-700 W
Impedance:	DVC 4 ohms
Sensitivity:	83.1 dB (1W/1m)
Frequency Response:	30-250 Hz
COMPRISING:
1 woofer	25.4 cm / 10"

DATOS TÉCNICOS

Power Rating:	350-700 W
Impedance:	DVC 2 ohms
Sensitivity:	84.5 dB (1W/1m)
Frequency Response:	30-250 Hz
COMPRISING:
1 woofer	30.48 cm / 12"

DATOS TÉCNICOS

Power Rating:	350-700 W
Impedance:	DVC 4 ohms
Sensitivity:	83.7 dB (1W/1m)
Frequency Response:	30-250 Hz
COMPRISING:
1 woofer	30.48 cm / 12"

DATOS TÉCNICOS

PARALLEL COILS / PARALLEL SUBS

SERIES COILS

SERIES COILS / PARALLEL SUBS

SERIES COILS / PARALLEL SUBS

SERIES COILS / PARALLEL SUBS

DVC 4-Ohm Coil Wiring

PARALLEL COILS

PARALLEL COILS / PARALLEL SUBS

SERIES COILS

SERIES COILS / PARALLEL SUBS

SERIES COILS / PARALLEL SUBS

SERIES COILS / PARALLEL SUBS

graph TD
    A["1"] -->|1+ 1-| B["2"]
    A -->|2- 2+| C["3"]
    D["2"] -->|1+ 1-| E["3"]
    D -->|2- 2+| F["4"]
    G["4"] -->|1+ 1-| H["-"]
    G -->|2- 2+| I["+"]
    style A fill:#ccc
    style D fill:#ccc
    style G fill:#ccc
    style B fill:#ccc
    style C fill:#ccc
    style E fill:#ccc
    style F fill:#ccc

REFERENCE SERIES SUBWOOFERS

ELECTRICAL	RWM252	RWM254	RWM302	RWM304
WIRING	Series	Series	Series	Series
NomZ	4.344	8.7	4.344	8.784	Ohm
Sd	0.034	0.034	0.0511	0.0511	sqM
Revc	3.62	7.25	3.62	7.32	Ohm
BL	11.07	14.25	11.32	14.62	TxM
Vas	35.38	38.39	63.35	70.97	Liters
Cms	215.8	234.2	171	191.6	uM/N
Mms	127.9	118.5	170.2	170	Grams
Fo	30.38	30.26	29.53	27.94	Hz
Qms	3.474	3.29	2.858	3.25
Qes	0.722	0.8	0.892	1.02
Qts	0.596	0.64	0.68	0.78
no	0.132	0.128	0.176	0.146	%
SPL@1W	83.3	83.1	84.5	83.68	dB
SPL@2.83W	86.81	83.65	88.05	84.19	dB
Xmax/Over Hang	9.5	9.5	9.5	9.5	mm
Xmech/Suspension	14.25	14.25	15	15	mm
RMS	350	350	350	350	Watts
PEAK	700	700	700	700	Watts

CLOSED BOX DESIGNS (SEALED)

Standard Tight Bass-Small Box
Box Volume	0.7	0.7	1.15	1.15	Cubic Feet
Qtc	0.969	1.064	1.13	1.334
F3	41	40	38	36	Hz

VENTED BOX DESIGNS (ROUND PORT)

Standard Tight Bass-Small Box
Box Volume	1	1	1.5	1.5	Cubic Feet
Fb	45	45	45	45	Hz
Round Port Size	3	3	4	4	Inches
Port Length	8	8	9.5	9.5	Inches
F3	37	37	37	37	Hz

Optimal Sound Quality-Flat Response

Box Volume	1.5	1.5	2.25	2.25	Cubic Feet
Fb	44	44	44	44	Hz
Slot Port Size (Inches)	10 x 1.5	10 x 1.5	12.5 x 2	12.5 x 2	Inches
Port Length (Inches)	17.5	17.5	19.5	19.5	Inches
F3	35	35	35	35	Hz

FEATURES ARE SUBJECT TO CHANGE WITHOUT NOTICE

NOTE: All above box volumes are internal values and already include subwoofer and port displacement.

Volume listed represents the volume of an empty box using 3/4" MDF.

The F3 value represents the -3db cut off of the sub/enclosure combination in Hz.

SUBWOOFER INSTALLATION DIRECTIONS

Enclosure Materials

Typically, 5/8" or 3/4" MDF (Medium Density Fiber Board) is best for most applications. 3/4" MDF is recommended.

Enclosure Build Materials

Connecting joints need to be glued and screwed to ensure no air escapes and joints do not separate under high pressure.

Mitered and rabbit joints also help to ensure the enclosure joints are secure.

Bracing

Internal bracing is also recommended to prevent flexing and to strengthen the enclosure.

Note: The volume taken up by the bracing should be added to the total enclosure interior volume.

There are two common bracing methods.

1. Corner Bracing: These help prevent the connection joints from separating under heavy vibration and air pressure.

Use 1" x 1" MDF at all interior joints

1. Diagonal Bracing: These internal braces connect the top side to the bottom side as well front side to back side. This prevents the wood from bowing or pushing outwards.

Use 1" x 2" with 1" surface contact that is glued and screwed.

Glossary of Terms

Q The energy losses of relative damping (ratio of stored to dissipated energy or ratio of reactive to resistive energy).

Fs Free air resonance of driver in Hz.

Qms Mechanical Q.

Vas Volume of air equivalent to driver from the rest position.

Cms Mechanical compliance of a loud speaker piston.

Mms Moving mass of total loud speaker piston assembly.

Xmax The maximum linear excursion of a loud speaker.

Sd Surface area of the cone.

Dia The piston diameter of a loud speaker.

Qes Electrical Q of a system.

Re DC resistance.

Le VC inductance.

Pe Maximum input power.

Qts Total Q of the system.

Sens Sensitivity. An efficiency measurement in dB's.

Vc Volume of a closed or sealed enclosure

Vb Volume of a vented enclosure.

Fc The resonant frequency of a closed or sealed system

Fb The resonant frequency of a vented system

F3 The half-power (-3dB) frequency of a loud speaker enclosure

Qtc The Q of a loud speaker at Fc in a closed box, considering both it's electrical and mechanical resistance.

QL The Q of a vented box, resulting from all box losses.

DV Diameter of vent.

LV Length of vent.

H Height.

W Width.

D Depth

Maxxsonics Limited Warranty

As the manufacturer of Maxxsonics, Autotek, Crunch, MB Quart and Hifonics car audio products, Maxxsonics USA Inc. Warrants to the original consumer purchaser the amplifier to be free from defects in material and workmanship for one (1) Year from date of purchase.

All other parts and accessories of the system are warranted to be free from defects in material and workmanship for one (1) year from date of purchase. Maxxsonics will repair or replace at its option and free of charge during the warranty period, any system component that proves defective in materials and workmanship under normal installation, use and service provided that the product is returned to the authorized Maxxsonics dealer from where it was purchased. A photo copy of the original receipt must accompany the product being returned.

Valid purchase receipts will contain the name and address of the authorized reseller.

Any damage to the product as a result of misuse, abuse, accident, incorrect wiring, improper installation, alteration of date code or bar code labels, revolution, natural disaster, or any sneaky stuff because someone messed up, repair or alteration out side of our factory or authorized service centers and any thing else you have done that you should not have done is not covered.

This warranty is limited to defective parts and specifically excludes any incidental or consequential damages connected therewith. This warranty is not to be construed as an insurance policy.

Warranty on installation labor, removal, re-installation and freight charges are not the responsibility of Maxxsonics USA Inc.

Warranty products damaged as a result of insufficient or improper packing materials are not covered by this limited warranty and such damaged product will be returned "as is" at the expense of the owner.