Car amplifiers power the speakers in your car stereo system to provide crisp sound quality at high volumes. Each speaker requires one channel of amplification. This means a 4-channel amplifier, will support four speakers.

Car Amplifier Quality

If you want to use your Car audio system in high ambient noise, you need good amplification quality. Most factory-installed head units have modest amplification [10 watts per channel or less]; many aftermarket head units have at least twice that.

The more power the amp your car sound system delivers, the cleaner the sound at the speakers. But ratings can be confusing.

A receiver rated at 50 watts maximum power most likely has only 20 watts of clean power. For that reason, serious mobile listeners replace built in amplifiers with powerful external amplifiers.

The easiest and typically least expensive installation is a single amplifier that powers all the speakers in a car system.

The three main factors that specify car amplifiers are :

Channels
Wattage Per Channel
Crossover

Car Amplifier Channels

The number of channels listed on the amplifier dictates the number of speakers it supports. A single channel is only capable of powering one speaker. The more channels; generally the higher the price. Four-channel amps are the most popular.

Wattage Per Channel

To use your car audio system in high ambient noise, you need good amplification quality. Most factory-installed head units have modest amplification [10 watts per channel or less]; many after-market head units have at least twice that. The more power the amp your car sound system delivers, the cleaner the sound at the speakers. But ratings can be confusing. A receiver rated at 50 watts maximum power likely has only 20 watts of clean power. For that reason, serious mobile listeners replace built in amplifiers with powerful external amplifiers.

The easiest and typically least expensive installation is a single amplifier that powers all the speakers in a car system.

Crossover

When a car amplifier contains its own crossovers, this means it contains circuits that split the music frequencies, giving surround sound effects such as the highs to the front speakers and the lows to the rear speakers.

This helps maximize power delivery to the speakers and improves sound. Make sure you can control these crossovers. Some amplifiers have rotary controls, whilst others need a screwdriver for adjustment.

Other Important Amplifier Feature

Other features of car amplifiers that you should consider are:

Soft-start circuitry - eliminates the thumps and thuds that can damage car speakers and irritate listeners.
Number of Speaker-level and line-level outputs and inputs - Make sure you have enough for the setup you are currently installing, with at least one spare for future upgrade.
Heat Dissipation – amps generate a lot of heat that impacts sound so look for efficient cooling design. Common design includes: metal fins to increase surface area for air cooling or liquid coolant.