Hertz ML Power 5 Amplifier: Advanced Web Manual

1. Introduction

Thank you for purchasing a Hertz product, designed according to the highest quality standards. Your ML Power amplifier is a cutting-edge product of compact size, providing high power and quality of sound. It will definitely ensure you maximum satisfaction by taking up very small room in your vehicle. Before the installation, in addition to reading the Quick Start Guide (QSG), the consultation of this user's manual available on the Hertz website will let you achieve the highest performance from your amplifier.

2. Package Contents

In the package, besides your amplifier, you will find:

• Quick Start Guide
• Warranty Card
• 2 x 40 A blade fuse
• 4 x 4.2 x 16 mm self-tapping, cross-headed fixing screws
• Optional: HRC BM: SUB volume control

3. Safe Sound

Hertz amplifiers can be part of a high power audio system that can generate very high undistorted sound pressure levels. Please remember that long exposure to an excessively high sound pressure level may damage your hearing; therefore, please use common sense and practice safe sound.

Safety must be at the forefront while driving. The listening volume should never obscure the noise coming from the outside of your vehicle; you should be able to hear the sounds generated by your vehicle in order to promptly face any emergency situation.

To achieve the best possible performance from your new components, we recommend you follow the instructions in this manual carefully. To design and create top-level car hi-fi systems, you need to understand automobile mechanical and electrical issues very well. If you think you lack the required knowledge or the proper tools, please consult with a specialized installer. A professional installation will ensure your system delivers all the performance you have paid for, without affecting the safety and reliability of your vehicle.

This manual has been designed to provide you with the basic instructions required to install and use this product. However, the range of possible applications is very wide; to obtain further information, please contact your authorized Hertz dealer or Hertz service center.

You can also send an e-mail directly to the following addresses:

• Italy - supporto.tecnico@elettromedia.it
• Worldwide - support@elettromedia.it

4. General Precautions

• This symbol [?] indicates that you have to pay attention to these instructions. Disregarding them might cause accidental harms or damage your amplifier.
• Before installing the amplifier, make sure you carefully read and understand all instructions.
• The vehicle electric system must have 12V DC voltage with negative to ground. Make sure your car has it in order to avoid any damages to your amplifier and to the vehicle.
• Pre-plan the configuration of your new amplifier and the best wiring routes to ease installation.
• Always wear protective eyewear when using tools that may generate splinters.
• During installation, keep the amplifier in its packing as long as possible; this will protect it from damages.
• Secure all auxiliary devices you built to install the components to the vehicle structure through brackets, screws, nuts and bolts; this ensures stability and safety while driving.
• The amplifier detachment while driving can damage the people in the vehicle and other cars. Secure the amplifier at best, paying utmost attention if installation is inside the passenger's compartment. Do not carry out any installation inside the engine compartment.
• Before installing the amplifier, turn off the source and all other electronic devices in the audio system for preventing any damages.
• Make sure the location you chose for the components does not affect the correct functioning of the vehicle mechanic and electric devices.
• Do not run the cables or install the amplifier next to electronic gearcases.
• Use extreme caution when cutting or drilling the car plate, checking there are no electrical wiring or structural element underneath.
• Before connecting the power cable to the amplifier, disconnect the negative lead ( - ) from the car battery.
• Make sure power cable is not short circuited during installation and connection.
• Power cable must have mechanically resistant and self-extinguishing insulation. Its section has a size corresponding with what is suggested in this manual. Avoid to run it over or through sharp edges or close to moving mechanical devices. Make sure it is well fixed all along its length. Block positive and negative cables just close to the amplifier respective power supply terminal blocks through a clamping screw.
• Use rubber grommets to protect the wire if it runs in a hole of the plate or proper materials if it is close to heat-generating parts.
• To ground the device ( - ) in the right way, use a screw in the vehicle chassis; scrape all paint or grease from the metal if necessary, checking with a tester that there is continuity between the battery negative terminal ( - ) and the fixing point. If possible, connect all components to the same ground point; this solution rejects most noise.
• Route all signal cables away from power cables.
• Never run cables outside the vehicle; you would not be protected against wear and in case of accidents.
• When installing speakers and the cables that connect them, make sure that non-insulated parts never touch, even occasionally, the vehicle cutting parts. If they do, the amplifier protection is activated.
• To prevent all problems, use very good quality cables, connectors and accessories, choosing them in Connection catalogue.
• When installation is over, and before plugging the main power supply fuse, check the system wiring and make sure all connections were done in the right way.
• Power amplifiers put an increased load on the battery and on its charging system. We recommend checking your alternator and battery condition to ensure they can handle the increased consumption. Standard electrical systems which are in good condition should be able to stand this extra load without problems but we recommend the use of an energy storage capacitor and/or a battery for high level audio systems.
• Put a fuse and its insulated fuse holder 40 cm max. far from the battery positive terminal; connect one end of the power cable to it after connecting the other end to the amplifier. The fuse value must be 50% higher than the amplifier built-in one. In case the cable supplies several amplifiers, the fuse value will have to be 50% higher than the sum of the values of all other fuses in the amplifiers.
• There must be good air circulation where the amplifier is installed; this area must not be affected by humidity, rain, external deposits or parts coming from the vehicle mechanical devices. Do not hinder in any way the cooling of the amplifier side fins.
• Install the amplifier in the vehicle parts where temperature is between 0°C (32°F) and 55°C (131°F).
• WARNING: When working in demanding conditions, the amplifier can reach temperatures of around 80 - 90°C (176-194°F). Make sure it is not dangerously hot before touching it.
• Periodically clean the amplifier without using aggressive solvents that might damage it. Dampen a piece of cloth with water and soap, wring it and clean the amplifier. Then use a piece of cloth dampened with water only; eventually clean the amplifier with a dry piece of cloth.
• Remove dust and solid deposits from the heat sink side fins. Don't use compressed air on the amplifier since it would push solid parts in the amplifiers. If necessary, please contact a specialised service centre for internal cleaning. Cooling system obstruction makes the amplifier go in safety mode.

5. Installation and Sizes

The physical dimensions of the Hertz ML Power 5 amplifier are as follows:

• Length (A): 349 mm (13.74 in)
• Width (B): 170 mm (6.69 in)
• Height (C): 46.7 mm (1.84 in)
• The diagram also indicates mounting hole dimensions D and E.

6. Battery / Remote Connection and How to Replace the Fuse

This section describes the connection of the power supply and the remote turn-on wire. It also details fuse replacement.

• Power Connection: Connect the positive cable to the +BATTERY terminal and the negative cable to the GND terminal. A fuse holder with a 40A fuse should be installed close to the positive battery pole to protect the +BATTERY wire. The amplifier itself is protected by two internal 40A blade fuses.
• Remote Connection: The REMOTE IN terminal receives a 7-15 V DC signal to turn the amplifier on. The REMOTE OUT terminal on the source unit can be used for this.

7. Auto Turn-On with Hi-Level Inputs

When the source unit does not have a 12V DC REMOTE OUT signal, the amplifier can be turned on automatically using the speaker-level inputs.

• To enable this feature, set the "HI AUTO TURN-ON" switch to the [ON] position. The amplifier will detect a signal on the speaker inputs and turn on.

8. Top Panel Controls: Switches and Adjustment Controls

The top panel features several controls for adjusting amplifier settings:

• 1. B CH LEVELS: Input sensitivity adjustment for B channels. Set to 1 position initially. Use a CD as source, increase head unit volume until output distorts, then increase volume by 1 step to eliminate distortion. Turn LEVELS up until sound becomes distorted and then turn LEVELS down slightly for optimum sound.
• 2. PASS MODE (HI - FULL): B channels filter switch. Select FULL to drive full range power outputs. The full frequencies bandwidth will be output to power output connectors. Select HI for Hi-pass to drive a MIDRANGE / TWEETER.
• 3. HI PASS (80 Hz 3.3 kHz): B channels HI-PASS crossover point adjustment. Rotating the knob selects frequencies between 80 Hz and 3.3 kHz. Frequencies below the crossover point will be attenuated at 12dB/Oct.
• 4. SUB LEVEL: SUB channel input sensitivity adjustment control. Set to 1 position. Use a CD as source, increase head unit volume until output distorts, then increase volume by 1 step to eliminate distortion. Turn LEVELS up until sound becomes distorted and then turn LEVELS down slightly for optimum sound.
• 5. REMOTE VOLUME CONTROL (ON - OFF): Activates [ON] or deactivates [OFF] external remote volume control for the SUB channel. Connect the external adjustment control to the front panel's proper connectors.
• 6. LO PASS (50 Hz 500 Hz): LO-PASS crossover point adjustment of A channels band-pass filter. Rotating the knob selects frequencies between 50 Hz and 500 Hz. Frequencies above the crossover point will be attenuated at 24dB/Oct.
• 7. A CH LEVELS: Input sensitivity adjustment for A channels. Set to 1 position. Use a CD as source, increase head unit volume until output distorts, then increase volume by 1 step to eliminate distortion. Turn LEVELS up until sound becomes distorted and then turn LEVELS down slightly for optimum sound.
• 8. PASS MODE (HI - FULL - BAND): A channels filter switch. Select FULL to drive full range power outputs. The full frequency bandwidth will be output to power output connectors. Select HI for Hi-pass to drive a WOOFER. Select BAND for bandpass to drive a WOOFER or a MIDRANGE.
• 9. HI PASS (40 Hz 150 Hz): A channels HI-PASS crossover point adjustment. Rotating the knob selects frequencies between 40 Hz and 150 Hz. Frequencies below the crossover point will be attenuated at 12dB/Oct.
• 10. LO PASS (80 Hz 3.3 kHz): A channels LO-PASS crossover point adjustment. Rotating the knob selects frequencies between 80 Hz and 3.3 kHz. Frequencies above the crossover point will be attenuated at 12dB/Oct.
• 11. MODE (3CH - 5CH): Switch for 3 channel or 5 channel amplifier mode. Select 5CH for A + B + SUB channel system (example: Front - Rear - Sub). Select 3CH for A (Dual Mono) + SUB system.
• 12. ON: Power LED. It lights up when the amplifier is turned on. If all LEDs (12, 13, 14, 15) turn on simultaneously, the amplifier will shut down and you will have to contact a service center.
• 13. TH: Thermal status LED. It lights up when thermal protection is active, above 85°C. The amplifier shuts down until the chassis temperature goes below 75°C.
• 14. OVL: Overload status LED. It lights up when overload occurs on the power output terminals. The amplifier goes into muting for 3 seconds and this LED starts flashing until you turn off the amplifier. REMOVE THE CAUSE OF OVERLOAD.
• 15. SPK: Speaker status LED. It lights up when a speaker touches the car body. The amplifier goes into muting for 3 seconds and this LED starts flashing until you turn off the amplifier. REMOVE THE CONTACT BETWEEN SPEAKER WIRE AND CAR BODY.

9. Front and Rear Panels

The front and rear panels of the ML Power 5 amplifier feature various input, output, and control connectors:

• 1. A PRE-IN: Left and Right pre-amplified inputs for A channels. Connect to pre-amplified source output. Signal can be 0.2 to 5V RMS.
• 2. B PRE-IN: Left and Right pre-amplified inputs for B channels. Connect to pre-amplified source output. Signal can be 0.2 to 5V RMS (input active in 5CH mode only).
• 3. SUB PRE-IN: Pre-amplified L+R (mix) inputs for the SUB channel. Connect to pre-amplified source output. Signal can be 0.2 to 5V RMS.
• 4. A HI - IN: Hi-Level signals Left and Right inputs for A channels. If the head unit does not feature a pre-amplified output, connect its speaker wire here to drive A Left and Right channels. Signal can be 0.8 V to 20 V RMS.
• 5. B HI - IN: Hi-Level signals Left and Right inputs for B channels. If the head unit does not feature a pre-amplified output, connect its speaker wire here to drive B Left and Right channels (input active in 5CH mode only). Signal can be 0.8 V to 20 V RMS.
• 6. B INPUT (A - B): Select A to drive B channels with A input signals. Do not connect B input in this setup. If the source features a REAR output, select B and connect its signals to B input (B PRE-IN or B HI-IN).
• 7. HI - IN AUTO TURN-ON (ON - OFF): Select ON to turn on the amplifier through the speaker power cable, if the source does not feature a 12V DC REMOTE OUT. Select OFF if REMOTE OUT from source is available.
• 8. SUB HI - IN: SUB channel Hi-Level signal inputs. If the head unit does not feature a pre-amplified output, connect its speaker wire here to drive the SUB channel. Signal can be 0.8 V to 20 V RMS.
• 9. REMOTE VOLUME CONTROL: Input for REMOTE SUB VOLUME CONTROL. Connect the optional adjustment control here.
• 10. SUB INPUT (A+B SUB): Select A+B to drive the SUB channel with A signals and B signals. Do not connect SUB input in this setup. If the source features a SUB output, select SUB and connect its signals to SUB input.
• 11. PROTECTION FUSE: 2 x 40A fuses.
• 12. POWER (+ BATT): Terminal block for the amplifier 11-15 V DC power supply positive pole connection. Insert the battery positive cable here. The plug accepts cables up to 2 A.W.G.
• 13. REMOTE IN: REMOTE IN terminal for the remote cable coming from the device which turns on the amplifier. Voltage must be between 7 and 16V DC.
• 14. POWER (GND): Terminal block for the amplifier power supply negative pole connection. Insert the battery negative cable or wire connected to the vehicle chassis here. The plug accepts cables up to 2 A.W.G.
• 15. SUB Speaker OUT: Subwoofer + and - power terminal.
• 16. BL Speaker OUT: B channel Left speaker + and - power terminal. For 3CH mode, connect the Left speaker negative terminal to BL-.
• 17. BR Speaker OUT: B channel Right speaker + and - power terminal. For 3CH mode, connect the Left speaker positive terminal to BR+.
• 18. AL Speaker OUT: A channel Left speaker + and - power terminal. For 3CH mode, connect the Right speaker negative terminal to AL-.
• 19. AR Speaker OUT: A channel Right speaker + and - power terminal. For 3CH mode, connect the Right speaker positive terminal to AR+.

10. Configuration Diagrams

The following diagrams illustrate various system configurations:

HOW TO USE REMOTE VOLUME CONTROL

This diagram shows how to connect an optional subwoofer remote volume control (HRC BM) to the amplifier for adjusting subwoofer volume independently. The control connects to the amplifier's dedicated input.

FRONT + REAR + SUB WITH REMOTE VOLUME CONTROL

This configuration uses pre-amplified inputs for front, rear, and subwoofer channels. The source's front outputs connect to the amplifier's FRONT PRE-IN L/R. The source's rear outputs connect to the amplifier's REAR PRE-IN L/R. The source's subwoofer output connects to the amplifier's SUB PRE-IN L+R. An optional remote volume control for the subwoofer is connected to the amplifier's front panel input. The amplifier's outputs are then connected to the respective front, rear, and subwoofer speakers.

WOOFER AND MID/HI AND SUB

This setup utilizes pre-amplified inputs for a woofer (A channels), mid/hi speakers (B channels), and a subwoofer. The source's front outputs connect to the amplifier's A PRE-IN L/R for the woofer. The source's rear outputs connect to the amplifier's B PRE-IN L/R for the mid/hi speakers. The source's subwoofer output connects to the amplifier's SUB PRE-IN L+R for the subwoofer. The amplifier's outputs are connected to the woofer, mid/hi speakers, and subwoofer.

PRE-IN FRONT AND PRE-IN SUB

This configuration uses pre-amplified inputs for front speakers (tweeters) and the subwoofer. The source's front outputs connect to the amplifier's FRONT PRE-IN L/R. The source's subwoofer output connects to the amplifier's SUB PRE-IN L+R. The amplifier's outputs are connected to the front speakers (tweeters) and the subwoofer.

PRE-IN FRONT, PRE-IN REAR AND PRE-IN SUB

This setup uses pre-amplified inputs for front, rear, and subwoofer channels. The source's front outputs connect to the amplifier's FRONT PRE-IN L/R. The source's rear outputs connect to the amplifier's REAR PRE-IN L/R. The source's subwoofer output connects to the amplifier's SUB PRE-IN L+R. The amplifier's outputs are connected to the front, rear, and subwoofer speakers.

HI-IN FRONT INPUTS WITH FRONT, REAR AND SUB OUTPUTS

This configuration uses high-level (speaker wire) inputs for front, rear, and subwoofer channels. The source's front speaker outputs connect to the amplifier's FRONT HI-IN L/R. The source's rear speaker outputs connect to the amplifier's REAR HI-IN L/R. The source's subwoofer speaker outputs connect to the amplifier's SUB HI-IN L+R. The amplifier's outputs are connected to the front, rear, and subwoofer speakers.

HI-IN FRONT AND REAR

This setup uses high-level (speaker wire) inputs for front and rear channels. The source's front speaker outputs connect to the amplifier's FRONT HI-IN L/R. The source's rear speaker outputs connect to the amplifier's REAR HI-IN L/R. The amplifier's outputs are connected to the front and rear speakers.

PRE-IN FRONT AND HI-IN REAR

This configuration uses pre-amplified inputs for front channels and high-level (speaker wire) inputs for rear channels. The source's front pre-amplified outputs connect to the amplifier's FRONT PRE-IN L/R. The source's rear speaker outputs connect to the amplifier's REAR HI-IN L/R. The amplifier's outputs are connected to the front and rear speakers.

3CH MODE: FRONT AND SUB

This diagram illustrates the 3-channel mode, typically used for a front component system and a subwoofer. The amplifier's A channels are configured for front output (possibly bridged for a woofer), and the SUB channel is for the subwoofer. The source's front outputs connect to the amplifier's FRONT PRE-IN L/R (or HI-IN L/R). The source's subwoofer output connects to the amplifier's SUB PRE-IN L+R (or HI-IN L+R). The MODE switch should be set to 3CH. The amplifier's A outputs are connected to the front speakers (woofer), and the SUB output is connected to the subwoofer.

11. Cables

For maximum performance, always use new, good quality cables. Their outer jacket must not be spoiled, and the copper must not show oxidation. For proper operation, always consider the length of the connection, the load, and the current it has to handle.

Power and Ground Cable Recommendations: The manual provides a table to help select the minimum cable section in gauge (A.W.G.) based on cable length and system current consumption. The formula to calculate system current consumption is provided: I = (TP x 2) / Vbatt, where I is current consumption in Amperes (A), TP is total power (RMS) of all amplifier channels, and Vbatt is the nominal automotive electrical system voltage (usually 12 V).

Speaker Cable Recommendations: A table is provided that refers to continuous power into a 4 Ohm load. It states that if the load decreases, the cable size will have to increase proportionally.

12. Block Diagram

The block diagram illustrates the internal signal flow of the ML Power 5 amplifier. Audio signals enter through various input stages, including PRE-IN (0.2-5V RMS) and HI-IN (0.8-20V RMS) for A, B, and SUB channels. Input selection switches (S1, S2, S3) route these signals. The amplifier features adjustable filters: HI-PASS for A channels (40-150 Hz), LO-PASS for A channels (80-3.3 kHz), HI-PASS for B channels (80-3.3 kHz), and LO-PASS for C (SUB) channels (50-500 Hz). PASS MODE switches (S4 for A, S2 for B) allow selection between FULL, HI-PASS, or BAND-PASS filtering. Level controls (P1, P2, P3) adjust input sensitivity. The MODE switch (S5) selects between 5-channel or 3-channel operation. An optional remote volume control for the subwoofer is also integrated. The output stages provide power to the A, B, and SUB channels, with specific configurations depending on the selected mode.

13. Technical Specifications