
ONYX
OWC254 / OWC304
Thank you for choosing the MB Quart ONYX 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 ONYX series subwoofers have been designed for the enthusiast looking for
accurate bass and solid reliability in their woofer. The ONYX series subwoofers
feature the following:
- Injection Molded Polypropylene Cone
- UV Resistant Butyl Rubber Surround
- 1.5” 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
OWC254 / OWC304

OWC254 / OWC304
DVC 4-Ohm Coil Wiring
-
+
SERIES COILS
1+ 1-
2- 2+
8-Ohms
SERIES COILS / PARALLEL SUBS
1+ 1-
2- 2+
-
+
-
+
1+ 1-
2- 2+
2.66-Ohms
-
+
1+ 1-
2- 2+
1 2
3
SERIES COILS / PARALLEL SUBS
1+ 1-
2- 2+
-
+
-
+
1+ 1-
2- 2+
2-Ohm
1 2
-
+
1+ 1-
2- 2+
3
-
+
1+ 1-
2- 2+
4
PARALLEL COILS
-
+
1+ 1-
2- 2+
2-Ohms
1+ 1-
2- 2+
SERIES COILS / PARALLEL SUBS
-
+
-
+
1+ 1-
2- 2+
4-Ohms
1 2
PARALLEL COILS / PARALLEL SUBS
1+ 1-
2- 2+
-
+
-
+
1+ 1-
2- 2+
1-Ohm
1 2

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
2. 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.
OWC254 / OWC304

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
Glossary of Terms
OWC254 / OWC304
MBQUART SPEAKERS
SPEAKER SYSTEM