Car amplifier wiring kit Why is it essential and how to choose the right one?
Cable gauge, OFC or CCA, fuse, ground, RCA: simply discover how to choose a wiring kit suitable for your amplifier and why a good power supply is essential for the safety and performance of your installation.
A good amplifier needs a good power supply
When preparing a Car Audio installation,
we naturally think about choosing the amplifier,
the subwoofer or the speakers.
However, the wiring kit
is just as important.
Its role is notably to properly route
the electrical energy from the battery to the amplifier,
while ensuring the protection of the installation.
An undersized cable, incorrect connections
or a bad ground can cause
voltage drops, overheating,
performance losses or protection modes.
A properly sized gauge helps to limit voltage losses between the battery and the amplifier.
A properly installed fuse protects the power cable in case of a short circuit.
A properly powered amplifier can operate under better conditions.
What does an amplifier wiring kit contain?
A wiring kit generally brings together the main elements needed to connect an amplifier in a vehicle.
It connects the battery to the positive of the amplifier.
It allows you to connect the amplifier to the vehicle's ground.
It allows, when necessary, to control the turning on of the amplifier.
It carries the audio signal from the source to the amplifier.
They ensure the protection of the positive cable against dangerous overcurrents.
Terminals, sleeves and accessories facilitate a clean and secure installation.
Some kits may be delivered without RCA, without speaker cable or with different lengths. Always check the contents before purchase.
The cable gauge is more important than its appearance
A thick cable is not automatically a good cable.
To correctly choose your power supply, you must take into account the actual conductor gauge, its material, its length and the current required by the installation.
The greater the current required and the longer the distance, the more important it becomes to size the cable correctly.
What cable gauge to choose?
The cable gauge is expressed in mm².
We frequently encounter in Car Audio gauges such as: 6 mm², 10 mm², 16 mm², 20/21 mm², 35 mm² or 50 mm².
The following table constitutes a simplified reference for beginners. It does not replace the recommendations of your amplifier manufacturer.
| Indicative RMS power | Indicative gauge | Approximate AWG |
|---|---|---|
| Up to approximately 300 W RMS | 6 mm² | ≈ 10 AWG |
| 300 to 600 W RMS | 10 mm² | ≈ 8 AWG |
| 600 to 1000 W RMS | 16 mm² | ≈ 6 AWG |
| 1000 to 1500 W RMS | 20 to 25 mm² | ≈ 4 AWG |
| 1500 to 2500 W RMS | 35 mm² | ≈ 2 AWG |
| Very powerful installations | 50 mm² or several cables depending on the need | ≈ 0 / 1/0 AWG and more |
A cable gauge should not be chosen
solely from the announced RMS watts.
You must also take into account
the actual consumption of the amplifier,
its efficiency, the length of the cable,
the material used and the manufacturer's recommendations.
Why is the cable length important?
The longer a cable is, the more its total electrical resistance increases.
On an installation consuming a lot of current, this can increase the voltage drop between the battery and the amplifier.
A cable perfectly suitable
for a very short connection
is not necessarily the best choice
to cross an entire vehicle.
Over a long length,
it may be necessary to switch
to a higher gauge.
OFC or CCA: what difference?
You will mainly encounter two types of cables in Car Audio kits: OFC and CCA.
OFC
Oxygen Free Copper
High purity copper conductor.
At the same gauge, its conductivity is better
than that of a CCA cable.
It is particularly interesting
for installations requiring
high currents.
CCA
Copper Clad Aluminum
Aluminum conductor covered with copper.
It is generally less expensive,
but has a higher electrical resistance
at the same gauge.
It must therefore be sized
accordingly.
For amplifiers requiring a lot of current, Sound Auto Concept generally recommends a properly sized OFC cable.
Do not rely solely on the outer diameter of the cable
Two cables that seem to have the same outer diameter can contain a very different amount of conductor.
A particularly thick sleeve can give the impression of having a thick cable while the actual conductor gauge is lower.
So always check the actual gauge announced in mm² and the composition of the conductor.
Why is the fuse essential?
The main fuse is an essential safety element.
Its main role is to protect the power cable in case of a short circuit or overcurrent.
A car battery is capable
of providing a very high short-circuit current.
If the positive cable accidentally touches
the bodywork and no suitable protection
is present, the cable can get very hot.
The fuse holder must therefore be installed as close as possible to the battery, generally within the first few dozen centimeters when the vehicle configuration allows it.
How to choose the right fuse?
The fuse should not simply be chosen because the amplifier is powerful.
The protection must notably be adapted to the allowable capacity of the cable used and the configuration of the installation.
The fuse located near the battery
protects above all the cable.
Consult the recommendations of the manufacturer
of the kit, the cable and the amplifier
to choose suitable protection.
The ground is as important as the positive cable
Many installation problems come from a bad ground.
Using an excellent positive cable is useless if the ground return is poorly made.
- Use a suitable ground gauge.
- Choose an appropriate ground point.
- Ensure a clean electrical contact.
- Tighten the connection properly.
- Avoid improvised connections.
voltage drops, unstable operation, interference, protection modes or overheating of the connections.
What is the RCA cable used for?
Unlike the thick power cable, the RCA does not provide electrical power to the amplifier.
It carries the low-level audio signal coming from the car radio, the DSP or another source.
A properly made cable, properly connected and properly routed helps limit interference problems.
When possible,
neatly organize the signal cables
and the power cables.
Avoid especially creating
unnecessary lengths or fragile connections.
What is the Remote cable used for?
The REM or Remote cable is generally used to control the turning on of the amplifier.
When the car radio turns on, its Remote output can send a control voltage to the amplifier, which then starts operating.
Some modern installations use however other ignition methods, notably automatic signal detection.
A single 50 mm² cable is not always enough
On very high power Car Audio installations, the current requirements can become considerable.
In this case, the sizing may require several power cables, splitters, several fuses, additional batteries or an upgrade to the vehicle's charging system.
For this type of project, it is preferable to calculate the complete installation rather than simply buying the biggest kit available.
The essential rules for installing your wiring
- Disconnect the battery before working when the vehicle procedure allows it.
- Install the fuse holder near the battery.
- Protect the cable when it crosses a sheet metal.
- Use suitable cable glands.
- Avoid very hot areas.
- Avoid moving parts and sharp edges.
- Do not pinch the cables under metal elements.
- Make sure all connections are properly crimped and tightened.
- Check the polarity before turning on the power.
- Check your installation before inserting the main fuse.
Common mistakes with a wiring kit
An insufficient cross-section increases cable losses and overheating.
With the same cross-section, the two materials do not have the same electrical resistance.
The section between the battery and the fuse would then be less protected.
A poor ground can disrupt the entire installation.
Length, current, material, and efficiency also matter.
A cable rubbing against sheet metal can eventually damage its insulation.
How to choose your wiring kit?
Check the manufacturer's recommendations for your amplifier.
Determine the required length between the battery and the amplifier.
Choose a cross-section suitable for the current that the cable will need to carry.
Check whether it is OFC copper or CCA.
Install a properly sized fuse near the battery.
Give as much importance to the ground as to the positive cable.
Frequently Asked Questions About Car Audio Wiring
What cable cross-section should I choose for my amplifier?
It depends on the current consumed, the length of the cable, its material, and the recommendations of the amplifier manufacturer. The higher the consumption and the greater the distance, the larger the cross-section may be required.
What is the difference between OFC and CCA?
OFC is a copper conductor that offers better conductivity than CCA of the same cross-section. CCA mainly uses aluminum coated with copper and has a higher electrical resistance.
Is OFC cable mandatory?
No, but it is generally the preferred choice for installations requiring high currents. A CCA cable must be sized taking its electrical characteristics into account.
Why should a fuse be placed near the battery?
To minimize the length of unprotected positive cable. The main fuse is also used to protect the cable in the event of a short circuit.
How long of a cable should I plan for?
It depends on the vehicle and the location of the amplifier. Many kits offer around 5 meters of positive cable, which is suitable for many installations, but you should measure your vehicle before purchasing.
Why does my amplifier go into protection mode?
There can be many causes: voltage drop, poor ground, short circuit, incorrect impedance, overheating, or wiring issues. You should perform a diagnostic before continuing to use the installation.
Is a wiring kit universal?
Kits can be used with many amplifiers, but their cross-section and contents must match the needs of your installation. Therefore, there is no single kit suitable for all amplifiers.
Can I install a wiring kit myself?
Yes, if you know the basics of automotive electricity and follow safety instructions. If in doubt, especially with a high-power installation, have the installation checked by a professional.
Choose wiring suitable for your installation
A good wiring kit does not simply
connect your battery to your amplifier.
It directly contributes to
the safety, electrical stability
and proper operation of your Car Audio system.
Not sure which cross-section to choose?
Sound Auto Concept can advise you
based on your amplifier and installation.
Sound Auto Concept
1 Rue de la Manufacture Semely, 34120 Pézenas
09.85.13.66.35
fabrication@soundautoconcept.com