Crunch GRP12D4 User manual

1
Congratulations on your purchase of the new CRUNCH Ground
Pounder GRP Series subwoofer system. The GRP subwoofer series
offer incredible output, great sound quality and outstanding
good looks.
As with all high quality car audio products, we recommend
professional installation by an authorised Crunch dealer.
Your dealers knowledge and experience can ensure a problem free
and cosmetically integrated installation.
If you choose to install the subwoofers yourself, please read the
entire manual very carefully.
12-Inch DVC / SVC Subwoofer
Dual 4-Ohm / Single 4-Ohm Voice Coil
High Energy Magnet
Ultra Rigid Pressed Paper PPC Cone
Foam Gasket
Multi-Layer High-Temp VC
Polypropylene Dust Cap
Front-Plate & Voice-Coil Cooling
Poly Cotton Spider
Hi-Excursion Foam Surround
Anti-Resonant Magnet Boot
GROUND POUNDER
GRP SERIES
CAR AUDIO SUBWOOFERS
CRUNCH

2
SUBWOOFER INSTALLATION AND WIRING 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.
Wiring
Wiring Parallel, Series or Parallel/Series will affect the final
impedance at the amp and great care must taken to ensure the
amp is not driven below it’s intended impedance capabilities.
Mounting
Please ensure that subwoofers are mounted securely to the
enclosure using each screw hole provided. Also, be sure to
securely fasten the subwoofer enclosure to the vehicle.

3
Parameters GRP12S4 GRP12D4
Wiring - SERIES Coils
NomZ 4.44 9.12 Ohm
Sd 0.051 0.051 sqM
Revc 3.7 7.6 Ohm
BL 10.18 13.73 TxM
Vas 60.4 60.5 Liter
Cms 160.6 160.9 uM/N
Mms 122.4 117.1 Grams
Fs 35.88 36.37 Hz
Qm s 6.4 7.84
Qes 0.984 1.087
Qts 0.853 0.955
no 0.274 0.265 %
SPL@1W 86.4 86.2 dB
Xmax 6 6 mm
Rms 250 250 Watts
Maxx 500 500 Watts
Box Volume 1.5 / 42.48 1.5 / 42.48 Cubic Feet / Liters
Qtc 1.26 1.4
F3 41 41 Hz
Box Volume 2.1 / 59.47 2.1 / 59.47 Cubic Feet / Liters
Qtc 1.14 1.27
F3 38 38 Hz
Box Volume 2.1 / 59.47 2.1 / 59.47 Cubic Feet / Liters
Fb 37 37 Hz
Port Size (Diam) 4 / 101.6 4 / 101.6 Inches/ Millimeters
Port Length 10 / 254 10 / 254 Inches/ Millimeters
F3 33 34 Hz
GROUND POUNDER GRP SERIES SUBW OOFERS
CLOSED BOX DESIGNS (SEALED)
VENTED BOX DESIGNS (ROUND PORT)
NOTE: All above box volum es are internal values and already include subw oofer and port displacement.
The F3 value represents the -3db cut off of the enclosure in Hz.
Polyfill may be added to sealed enclousres to reach the desired Q-Value.
Standard Boomie ( Hip Hop-Rap)
Optimal Sound Quality - Flat Response
Standard Tight Bass
FEATURES ARE SUBJECT TO CHANGE W ITHOUT NOTICE

4
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

5
GRP12S4
SVC 4-Ohms
+
-4-Ohms
+
-
PARALLEL
+
-2-Ohms
SERIES
+
-8-Ohms
+
-
+
-
+
-
+
-

6
GRP12D4
DVC 4-Ohms
PARALLEL COILS / PARALLEL SUBS
+
-1-Ohm
+
-
+
-
SERIES COILS / PARALLEL SUBS
4-Ohms
+
-
++
--
+
-
+
-
+
-
+
-
SERIES
PARALLEL
+
-8-Ohms
+
-2-Ohms +
-
+
-
+
-
+
-

14
7
SUBWOOFER DIMENSIONS
5.7” / 144mm
Mounting Depth
When designing an enclosure for this subwoofer, please
ensure to leave atleast 2” of clearance from the back of
the motor to the back of the enclousre.
12.2” / 310mm Outside Diameter
11” / 279mm

14
8
As the manufacturer of Maxxsonics, MB Quart, Autotek, Crunch 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 warrantied to be free from defects in
material and workmanship for one (1) year from date of purchase. Maxxsonics will
repair or replace at it’s 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.
Maxxsonics Limited Warranty