In-Car Audio

Getting the music out

Getting the best sound out of your in-car audio system is more than just a matter of buying the best (or most expensive) components. It is a combination of choosing the right components and installing them correctly.

For example, you can have a powerful and expensive amplifier, but without enough electrical current to it the results will be very disappointing. Correct matching of components and proper installation is the largest contributing factor to the success of a system.

More is not necessarily better. Too many speakers can give your car volume, but not one cohesive sound. More components also mean a longer way for signal to travel and more risk of distortion.

For most cars, an ideal in-car audio system is based on a head unit with one or two amplifiers, one superb set of front speakers (which are responsible for the majority of the final result) and a small subwoofer.


Amplifiers provide the power, measured in Watts, to drive the speakers. Factory-installed head units have an amplifier built in, but only a relatively small one (often 10 watts per channel or less). Many aftermarket head units have at least twice that. The more power your amp delivers, the cleaner the sound at the speakers (as long as it doesn't exceed the capacity of the speakers). Serious audiophiles eschew the modest amps built into head units and go for powerful external amplifiers instead. They really can make a big difference to your in-car sound.


For the easiest (and cheapest) installation, look for a single amplifier to power all your speakers. This would be the number of channels listed on the amp (a single channel powers one speaker). And look for an amplifier that contains its own crossovers (filters). These circuits split the music frequencies so (for example) the highs go to the front speakers while the lows go the rear speakers and/or to the tweeters and woofers, for maximum power and sound clarity. If you add a subwoofer for beefy low-end bass, you'll usually need a separate amplifier just for that.

Depending on your application, the number of speaker-level and line-level outputs and inputs need to be considered. Make sure you have enough for the setup you are currently installing, while leaving room for at least one future upgrade.

Amps can generate a quite a bit of heat, which affects performance. Usually, metal fins are built into the amp to help dissipate heat, but location can also be an important factor. Some advanced systems even use liquid cooling to keep the temperature down.

Amps can be installed inside the car, but many get mounted in the boot (along with CD stackers etc). This, of course, requires running cables from the head unit in the dash. Note that amp position and placement can be affected by accessibility issues, heat, noise and interference.

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