GZRA 2HD - Receiver Ground Zero - Free user manual and instructions

Product Type	2-Channel Class D Amplifier
Series	RADIOACTIVE
Amplifier Class	D
Number of Channels	2
RMS Power @ 4 Ω (1% THD+N)	2 x 285 W
RMS Power @ 2 Ω (1% THD+N)	2 x 450 W
RMS Power @ 4 Ω Bridged (1% THD+N)	1 x 900 W
RMS Power @ 4 Ω Bridged (10% THD+N)	1 x 1150 W
Frequency Response	10 Hz – 25 kHz
Signal-to-Noise Ratio	-101.9 dB
Total Harmonic Distortion (THD+N)	< 0.1%
Damping Factor	> 200
Input Sensitivity	200 mV – 5.3 V
Low Pass Filter	40 Hz – 4000 Hz, 12 dB/oct
High Pass Filter	40 Hz – 4000 Hz, 12 dB/oct
Bass Boost	0 – 12 dB @ 45 Hz
Input Connections	RCA line input, High-level speaker input
Speaker Output Connections	2-channel stereo or bridged mono
Remote Control	Wired bass level remote (optional)
Auto-On Function	Yes (via high-level input)
Turn-On Delay	Yes
Status Indicators	Power (green), Protect (red)
Protection Circuits	Thermal, Short circuit, Overheating
Power Supply Voltage	12 V DC (negative ground)
Fuse Rating	3 x 30 A (amplifier), Recommended main fuse: 100 A
Dimensions (H x W x D) - Overall	52 x 186 x 268 mm
Recommended Speaker Wire	min 2.5 mm² / 13 AWG
Recommended Power Wire	min 20 mm² / 4 AWG

Frequently Asked Questions - GZRA 2HD Ground Zero

What are the power output ratings for the GZRA 2HD?

The GZRA 2HD delivers RMS power of 2 x 285 W at 4 Ω, 2 x 450 W at 2 Ω (1% THD+N), and 1 x 900 W at 4 Ω bridged (1% THD+N), or 1 x 1150 W at 4 Ω bridged (10% THD+N).

Can I use both RCA and high-level inputs simultaneously?

No, never use both inputs at the same time. Doing so may cause serious damage to the amplifier. Choose either RCA or high-level input, not both.

How do I set the crossover frequency?

Use the low pass filter and high pass filter controls on the amplifier. Adjust each from 40 Hz to 4000 Hz with a 12 dB/octave slope to suit your speakers or subwoofers.

What does the PROTECT LED indicate?

A red PROTECT LED indicates the amplifier has entered protection mode, usually due to a speaker short circuit, overheating, or an unstable load. Check speaker wiring and ensure adequate cooling.

How do I connect the bass remote control?

Connect the optional wired bass level remote control (GZTA Bassremote) to the Remote socket on the amplifier. This allows you to adjust the bass boost level from the driver's seat.

What is the recommended power and ground wire gauge?

GROUND ZERO recommends using a minimum of 20 mm² (4 AWG) for power and ground wires. The power wire must be fused within 20 cm (8 inches) of the battery with the recommended main fuse (100 A).

How do I bridge the amplifier for a single subwoofer?

Connect the subwoofer to the positive (+) terminal of Channel 1 and the negative (-) terminal of Channel 2. Ensure the load impedance is at least 4 Ω in bridged mode.

What is the auto-on feature and how does it work?

When using the high-level input (speaker wire from head unit), the amplifier automatically turns on when it detects an audio signal. The remote terminal on the power connector can remain unused.

What should I do if the amplifier turns off at high volume?

This likely indicates overheating or a low impedance load. Reduce the volume, allow the amplifier to cool, and check that the speaker impedance is at least 2 Ω per channel stereo or 4 Ω bridged. Ensure good ventilation.

What are the dimensions of the GZRA 2HD?

The amplifier dimensions (overall) are 52 mm (H) x 186 mm (W) x 268 mm (D). Heatsink dimensions are 229 mm deep. It is compact for a 2-channel amplifier.

USER MANUAL GZRA 2HD Ground Zero

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www.ground-zero-audio.com

RADIOACTIVE SERIES

2-Channel Amplifier

GZRA 2HD

Owner's manual

(AWV2.0

Main Features

• High-performance class D amplifier
• 2 ohms stable in stereo mode
• 4 ohms stable in bridged mode
• High-level input with auto-on feature
- Adjustable wide band active crossover
• Bass boost control (0-12 dB @ 45 Hz)
- Adjustable input sensitivity
- Wired bass level remote control (GZTA Bassremote available separately)
- Turn-on delay
• Thermal protection circuit

Thank you for choosing a great GROUND ZERO product! We hope you will enjoy this product from the IRIDIUM series. This owner's manual contains information you need to use this product. Please read it carefully in order to achieve the best possible result. Your car audio specialist or our customer support will answer further questions about the product and its use.

Subwoofers are an important part of your car audio system. Please keep in mind, however, that they can only achieve their full performance if all other components of the entire system are carefully coordinated with one another. It is therefore recommended consulting a car audio specialist dealer or workshop for the assembly of the system and its installation and sound adjustments.

RADIOACTIVE Serie – Advanced Dynamics

The RADIOACTIVE series contains a wide range of exceptional high-efficient loudspeakers and high-power subwoofers for daily use and SPL purpose. GROUND ZERO focused on overall natural and dynamical audio reproduction of each kind of music during the development of every single product. Compact but still powerful amplifiers class D amplifiers complete the line-up.

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

Safety instructions: Keep all parts of the content and the packaging away from children and pets to avoid accidents and the risk of suffocation. Permanently extreme levels of over 85 dB can lead to irreparable damage to the hearing. Music systems with high amplifier output power can reach levels of 130 dB or more. Extreme levels can also hinder the perception of important traffic noises and distract from what is happening on the road. Ground Zero GmbH and its sales partners expressly assume no responsibility for hearing damage, physical damage or any damage to property or consequential damage resulting from improper or careless use or improper installation of its products. In particular, any claims are forfeited through the use under competitive conditions.

Manufacturer's declaration: Hereby, Ground Zero GmbH declares that this product conforms to the rules of the following EU directives (including all applicable changes): 2011/65 / EU RoHS2 and 2001/95 / EC directive on general product safety.

The full text of the EU declaration of conformity is available at www.ground-zero-audio.com.

Loudspeakers contain magnetized metals and some valuable raw materials and must not be disposed of with normal household waste. Please leave defective or no longer required

Mounting instructions

• As a precaution, it is recommended to disconnect the vehicles 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 to the vehicle's gas tank, brake lines, to wirings or any other important vehicle parts!
• Never pass wires over sharp edges or vehicle parts due 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 it.

Recommended wiring

Speaker wires	min 2.5 mm ^2 / 13 AWG
Power supply wires	min 20 mm ^2 / 4 AWG

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1	Power terminal	+12V To be connected to the positive terminal of the batteryREM To be connected to the remote output of the head unit*(*not required in high-level input mode)GND To be connected to the vehicle's ground(or directly to the negative terminal of the battery)
2	Fuse(s)	If necessary to replace a defective fuse, it's strongly recommended to use a fuse with identical value
3	Speaker terminal	To connect the speaker wiresmin. 2 ohms load in stereo modemin. 4 ohms load in bridged mode
4	Bass boost control	To increase the bass level at 45 Hz up to 12 dB
5	Line input (RCA)	Input sockets to connect RCA wiresImportant note: High-level and RCA inputs should never be used simultaneously! This may cause serious damage to the amplifier
6	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 unusedImportant note: High-level and RCA inputs should never be used simultaneously! This may cause serious damage to the amplifier
7	Sensitivity control	Controller to adjust the input sensitivity
8	Low pass filter	To adjust the required crossover point. Frequencies above the selected crossover point will be filtered (40 Hz to 4000 Hz)
9	High pass filter	To adjust the required crossover point. Frequencies below the selected crossover point will be filtered (40 Hz to 4000 Hz)
10	Status indication	POWER (green) ok (correct operation)PROTECT (red) error (protection mode)
11	Remote socket	To connect the wired bass level remote control (available separately)

High-level input wiring

Speaker wiring in stereo mode

Geringste Lautsprecherimpedanz je 2 Ω
Minimum speaker impedance 2 Ω each

Speaker wiring in bridged mode

Geringste Loutsprecherimpedanz 4 Ω
Minimum speaker impedance 4 Ω

Model	GZRA 2HD
Amplifier type	2 channel class D
RMS Power @ 4 ΩCEA Standard CEA-2006-A	2x 285 W (1% THD+N)
RMS Power @ 2 ΩCEA Standard CEA-2006-A	2x 450 W (1% THD+N)
RMS Power @ 4 Ω in bridged modeCEA Standard CEA-2006-A	1x 900 W (1% THD+N)1x 1150 W (10% THD+N)
Low pass filter	40 Hz – 4000 Hz (12 dB/oct)
High pass filter	40 Hz – 4000 Hz (12 dB/oct)
Frequency response	10 Hz – 25 kHz
Signal to noise ratio (SNR)	-101.9 dB
Total harmonic distortion(THD+N)	< 0.1%
Damping factor	>200
Input sensitivity	200 mV – 5.3 V
Fuse(s)	3x 30 A
Recommended main fuse	100 A
Dimensionsw x h x l (heatsink / overall)	186 x 52 x 229/268 mm
Dimensionsw x h x l (heatsink / overall)	7.32 x 2.05 x 9.02/10.55"

Trouble shooting guide

Symptoms	Check / Cause	Action
No audible sound	Does the POW LED turn to green?	Check protection fuse(s) of the amplifier (harness)Check remote wire connection (RCA input mode)Check +12 Volt power supply wire connectionCheck ground wire connection
	Did the PROTECT LED turn to red?	Check for speaker short or amplifier overheating
Device does not turn on	Power supply of the amplifier?	Check power wire or connections
	Remote wire powered? (RCA input mode)	Check remote wire connection to the head unit
No sound on one channel	Speaker wiring undamaged?	Check for short circuit or open connections
	Input signal on each RCA lead?	Reverse left and right RCA inputs to check the audio input signal
Device turns off at medium / high volume	Load impedance of each speaker correct?	Check if each speaker load impedance matches the technical specifications of the amplifier
Status LED turned on red	Temperature protection circuit active	Decrease head unit's volume / wait for cooling
	Speaker wires short / speaker damaged	Check speaker / wires and insulate if necessary

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!

Ground Zero GmbH

Erlenweg 25, 85658 Egmating, Germany Tel. [phone] Fax -8310

www.ground-zero-audio.com