Crunch GRP12S4, GRP12D4 Owners Manual

CRUNCH

GROUND POUNDER
GRP SERIES

CAR AUDIO SUBWOOFERS

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.

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

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.

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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.

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