User Manual for Ground Zero GZCS 100.2BMW Car Speaker System

Quick Guide

The Ground Zero GZCS 100.2BMW is a component loudspeaker system designed specifically for BMW vehicles. Due to the complexity of removing vehicle door panels and trim, professional installation by a car audio workshop is strongly recommended to avoid damage to the vehicle's interior, bodywork, or electrical systems.

Features

• BMW-specific 2-way loudspeaker system.
• Klippel-optimized midwoofer with neodymium motor and glass fiber cone.
• GZ-design aluminum cast basket.
• 25 mm silk dome tweeter with rear ventilation.
• 12/6 dB/oct crossover with level adjustment.
• Plug & Play connectors for BMW.

Safety and Installation

Follow these critical safety guidelines during installation:

• Never drill holes into the vehicle's gas tank, brake lines, wiring, or other vital components.
• Do not route cables over sharp edges that could cause damage.
• Keep signal and speaker cables away from antenna electronics and radio reception components.
• Always route power supply wiring separately from speaker wiring to prevent interference.
• Use adequately dimensioned power and speaker wires.
• High volume levels (over 85 dB) can cause permanent hearing damage.

Mounting Options

The system supports three mounting configurations depending on the vehicle requirements:

• Without mounting frame.
• Bottom-mounted frame.
• Top-mounted frame.

Crossover Settings

The in-line crossover allows for specific adjustments:

Tweeter Level Adjustment

• Black & green wire connected: 0 dB.
• Black & green wire not connected: -2 dB.

High Pass Filter (HPF) (@ 250 Hz / 6 dB/oct)

• Red & white wire not connected: HPF on (limits very low frequencies).
• Red & white wire connected: HPF off.

Specifications

• Nominal diameter: 100 mm (4") midrange & 25 mm (1") tweeter.
• Impedance: 4 Ohm.
• Frequency response: 70 Hz – 24 kHz.
• Power handling (RMS): 70 Watts.
• Power handling (max): 110 Watts.
• Efficiency (SPL): 87 dB.
• Resonance frequency: 77 Hz (midwoofer).