GROUND ZERO GZIA 135.4

Common Features

• High-quality Class A/B amplifier
• 2-ohms stable in stereo
• 4-ohms stable in bridged mode
• Variable low pass filter
• Variable high pass filter
• Bass boost function
• High-level input with auto-on
• Adjustable input sensitivity
• Turn-on delay & thermal protection circuit
• Wired level remote control included (Channel 3+4: LPF setting)

General Mounting Instructions

Important Precaution: As a precaution, it is recommended to disconnect the vehicle's battery before mounting the amplifier. Note: For new vehicles, disconnecting the battery might cause various errors in your vehicle's electric system that can be cleared only by authorized service partners of your vehicle's manufacturer! Please ask your service partner first before disconnecting the battery!

• The power supply wire (+12 V) has to be protected within max. 20 cm / 8" by a main fuse holder with a fuse value matching the recommendation for your amplifier. Note: If there is more than one amplifier connected using this power wire, the main fuse value must be equal to the sum of the recommended fuses of all connected devices. However, make sure the diameter of your power wire will be enough for the required current!
• If necessary, replace a defective fuse by a fuse with identical quality and value.
• Never drill holes into the vehicle's gas tank, brake lines, wirings, or any other important vehicle parts!
• Never pass wires over sharp edges or vehicle parts to avoid any kind of damage.
• Keep the wiring away from the antenna and electronic devices contributing to radio reception.
• Lay the power supply wiring always separated from speaker wiring to avoid disturbance.
• The amplifier contains a temperature protection circuit that turns the device off in case of overheating. After a certain cooling time, it will turn on automatically. To avoid heat build-up, enough air supply for cooling must be provided. Never cover the surface of the amplifier's heatsink entirely.
• The amplifier should NEVER be mounted onto a vibrating part or surface such as a subwoofer enclosure. This might lead to malfunction due to loosened electrical parts inside the amplifier.
• Some amplifiers offer a high-level input option; however, if a pre-amplified output (RCA) is available (at the head unit), it is strongly recommended to make use of them.
• Connections of RCA wires and loudspeaker cables, as well as switching of any switches, must be done while the amplifier is turned off.

Technical Data / Specifications

Controls & Features

The amplifier's top panel features connection terminals and controls, numbered for identification:

1. Power terminal:

Includes +12V (to be connected to the positive terminal of the battery), REM (to be connected to the remote output of the head unit; *not required in high-level mode), and GND (to be connected to the vehicle's ground or directly to the negative terminal of the battery).

2. Fuse(s):

Recommendation: A defective (blown) fuse needs to be replaced by a fuse with identical value and quality.

3. Speaker terminal:

To connect the speaker wires (min. load 2 ohms in stereo mode / 4 ohms in bridged mode).

4. Status indication:

POWER LED indicates correct operation; PROTECT LED indicates an error (protection mode active).

5. Remote input:

Input for connecting the cable remote control for volume adjustment.

6. High pass filter:

To adjust the required crossover point. Frequencies below the selected crossover point will be filtered (40 Hz to 3000 Hz).

7. Crossover switch:

To activate the high pass (HPF) or the low pass filter (LPF). In FLAT position, the whole frequency range will be reproduced.

8. Low pass filter:

To adjust the required crossover point. Frequencies above the selected crossover point will be filtered (30 Hz to 250 Hz).

9. Bass Boost:

This switch is used to increase the bass response at the frequency of 50 Hz to 6 or 12 dB.

10. Sensitivity control:

To adjust the input sensitivity.

11. Line input (RCA):

Input connectors to connect RCA signal cables. Important note: High-level and RCA inputs should never be used simultaneously! This may cause serious damage to the amplifier.

12. High-level input:

Head units without RCA pre-amplifier output signal can be connected using the high-level input to connect the speaker output of the head unit directly. If used, the amplifier turns on automatically (auto-on feature). The remote input of the power supply terminal remains unused. Important note: High-level and RCA inputs should never be used simultaneously! This may cause serious damage to the amplifier.

Troubleshooting Guide

Warranty & Terms

The warranty corresponds to the legal regulation. A return can only be made after prior arrangement and in the original packaging. Please enclose a machine-generated proof of purchase and a description of the defect. Defects caused by overload, improper handling, or participation in competitions are excluded from the warranty. Ground Zero reserves the right to make necessary changes or improvements to the product in the future without informing the customer.

Terms of warranty: The limited warranty for this product is covered by GROUND ZERO's regional distribution partners and their terms and conditions. For further information, contact your local retailer or distributor.

Safety Instructions / Manufacturer's Declaration

Safety Instructions: Do not expose the device to extreme temperatures, fire, high humidity, or direct contact with liquids. Do not use the device if it has been damaged or exposed to liquids. Keep the device, packaging, and accessories away from children and pets to prevent accidents and suffocation.

Manufacturer's Declaration: Herewith Ground Zero GmbH declares that this product complies with the directive 2014/30/EU (EMC) and further declares that this product is in conformity with the rules of the EU directives (including all applicable amendments) 2011/65/EU RoHS2 and 2001/95/EC General Product Safety directive. The full text of the Declaration of Conformity (EU) is available at the following internet address: www.ground-zero-audio.com. Electronic products contain valuable raw materials and must not be disposed of with normal household waste. At the end of its service life, please bring the device to your local recycling facility.

Respect the Music

Listening to music can be emotional, impressive, relaxing, or enjoyable. At that, it doesn't really matter what kind of music is the personal favorite, whether it's Instrumental, Jazz, Electro, Latin, Classic, Rock, or any other music direction. However, audio reproduction quality at each desired volume is elementary. Some music styles require higher levels while others prefer the soft tones. GROUND ZERO considers all the different wishes of customers during the development of new products. Along with this, the target is to create the most realistic sound, to transfer the soul of the music and the intention of the performer. Summarized to one phrase: RESPECT THE MUSIC!

Company Information

Ground Zero GmbH
Erlenweg 25, 85658 Egmating, Germany
Tel. +49 (0)8095/873 830 Fax -8310
www.ground-zero-audio.com

Ground Zero products are engineered in Germany. GROUND ZERO – international sponsor of EMMA (European Mobile Media Association).

Logos include the Ground Zero logo, EMMA sponsor logo, CE conformity mark, and a recycling symbol.