How to install an amplifier in a vehicle ?

When installing an amplifier in your vehicle, please note the following :

After reading the entire instruction manual, make sure you understand all the instructions before installing the amplifier. If you have any doubts about your ability to install the amplifier and wire the system properly, we recommend that you leave this task to a Focal dealer/installer.

In advance, it is essential to plan the layout of the system and the necessary wiring in the vehicle. During this preparation phase, it is essential to ensure that all settings remain accessible once the audio system has been installed. Before starting installation, please disconnect the negative wire from the car battery.


Because of the power it generates, the car audio amplifier produces considerable heat during operation. It should therefore be installed in a well-ventilated area.


  • Position the amplifier in the desired location.
  • Mark the location of the mounting holes.
  • Check that there are no objects behind the surface that could be damaged during drilling.
  • Remove the amplifier from its location, make sure you have a 3 mm diameter drill bit, then drill.
  • Reposition the amplifier in its intended location. Secure the amplifier using the 4 self-tapping screws supplied.

The mounting surface may have irregularities that make it difficult to secure the amplifier. In this case, we recommend mounting the amplifier with its mounting system on a wooden base fixed to the chosen wall.


Avoid routing power cables near low-level input cables (RCA), antennas, sensitive equipment and wiring harnesses. Power supply wires carry a high current that could interfere with the audio signal.

Keep cable lengths as short as possible to optimize installation quality and limit signal loss.

Which power cable cross-section should I choose?

Refer to the cable cross-section table :

Tableau de section des câbles en fonction de l'alimentation

Cable insulation

Run modulation cables (RCA), speaker cables, REMOTE cable and REMOTE CONTROL cable together, isolating them from other high-power automotive accessories, such as electric motors. We recommend that you retain the full length of the cables, which will be adjusted later.

Positive power supply

Route the positive (+) power supply cable, taking care to run it opposite the cables previously pulled, to avoid interference. Do not connect the cable immediately.

Negative power supply

Use the negative (-) power cable. Make sure this cable is as short as possible, ideally no more than 1 meter, to ensure a perfect connection between the amplifier and the vehicle chassis. The cable and its cross-section must comply with the specification table.

Find a suitable grounding point, then sand it to remove any traces of paint or varnish, thus ensuring better contact quality. Drill a hole in the sanded sheet metal to match the diameter of the screw you've chosen, ensuring that no cables, fuel tanks or other sensitive parts of the vehicle are in the vicinity. Strip 1 cm of cable, then tin it. Crimp or solder the cable to a cable lug. Insert the terminal into the screw, then fit the screw and its nut, and screw tight. On the other side, screw the cable firmly to the amplifier's GND terminal.

Modulation cables

Now you can connect the modulation cables (RCA), REMOTE cable and speaker cables. Connect the RCAs to the amplifier, observing the correct polarity (INPUT Left = black or white, INPUT Right = red).

Then connect the other end of the RCAs to the car radio's RCA* outputs (Left = left; Right = right).

Notice câble de modulation installation amplificateur Focal

Power cable

Start by preparing the positive (+) power cable by stripping 1 cm from the end to connect it to the amplifier. Then tin this part, using a soldering iron and tin wire. Insert the stripped, tinned end into the amplifier's "+ BATT" terminal, then screw the cable firmly in place.


The cable connecting the battery's positive (+) terminal to the amplifier's "+ BATT" terminal must be fused at a distance of 40 cm or less from the vehicle's battery. In addition, fuse-holder connections must be watertight.


The installation phase of the fuse holder designed to secure the system can now begin. The fuse-holder must be connected to both sides of the positive (+) power cable, and located close to the battery (10 to 40 cm). Remove the fuse holder, taking care to remove the fuse. Secure the fuse-holder base. Cut the red power cable between 10 and 40 cm (maximum) from the battery, retaining the cable off-cut which will be used to connect the other end of the fuse holder to the positive (+) terminal of the vehicle's battery.

Strip the cable by 1 cm, then tin it. Screw the cable into the fuse-holder terminal block.

Strip 1 cm from the other end, then screw the cable into the other fuse-holder terminal block.

Installation porte-fusible amplificateur Focal


To wire the loudspeakers, connect the loudspeaker cables to the right and left channel crossovers, respecting the polarities(+ = cable with red border in the case of a Focal kit) for traditional wiring. Note that Focal car audio amplifiers can operate in bridged mode to amplify a subwoofer. In this case, simply connect the positive speaker cable(+) to the BRIDGE(+) terminal block and connect the negative speaker cable(-) to the associated BRIDGE(-) terminal block.


When connecting several subwoofers to the same output, make sure the amplifier's impedance is compatible.

Connections, functions and settings

To optimize your on-board installation, please refer to your amplifier manual for detailed information on functions and settings. All manuals can be downloaded from this site, on the relevant product pages.

Connection haut-parleurs amplificateur car 'audio Focal


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