How to Choose The Best Amplifier for Your Car

A car amplifier will help improve the sound quality of your car’s audio system ad most cars nowadays come with built-in amps that are fixed into the head unit, but it might not be as powerful as you’d like. So if you want to upgrade the sound of your car’s stereo system, you’ll need a powerful car amplifier.

However, the amp you choose will have to factor in a few factors like if you’re using a subwoofer, the speakers, and where you’re planning to install the amp. Generally, the more powerful your car amp is, the better the sound it will produce provided your speakers can handle it.

Why do you need a car amplifier?

If you want your music to be loud, you’ll need an amp and it doesn’t matter if your system is wide open or soft so you can carry out a conversation, having a powerful amp will breathe life into your music. There are many benefits of adding an amp to your car stereo system.

  • You get better sound quality from your car amp so you can crank up the volume without hearing any distortions or rattling. The amp will produce clean and quality sound at all volume levels. And unlike the built-in amp, the external amp is designed without any limitation of space so it gives your speakers room to breathe and doesn’t overwork to produce better quality sound.
  • You can power a subwoofer since the amp provides more power than the built-in amp that comes with your car system. Your car stereo has an output of only 15 watts peak RMS which isn’t enough power to run a subwoofer that requires hundreds of watts. Your stereo also doesn’t have a crossover built into it or a dedicated sub-channel so it won’t produce the best sound.
  • You get more power for your upgraded speakers since you can’t use the factory amp to power your new high-quality speakers. These speakers will need more power to produce the best performance.

How much power does your aftermarket speakers need?

You should get an amp that has enough power to get your speakers to produce the best sound. So, whether you’re using your existing car speakers or upgraded speakers, make sure the power in your amp matches that of your speakers so you don’t end up under-powering your speakers. Most of the speakers come with an RMS power rating of between 5-60 watts. Look for an amp whose highest RMS power rating isn’t higher than your speaker’s highest RMS rating. You must match the RMS ratings of both your amp and speakers or subwoofer. So, if your amp has an RMS rating of 100 watts in its 4 channels, you’ll need 4 speakers or subwoofers with an RMS rating of 100 watts.

What is your speaker’s efficiency?

This refers to how well your speakers will perform with just a bit of power. So you could have a low-powered amp that can loud and clear sound without the need of adding another amp. Speakers that have a high-efficiency rating are mostly above 90dB and above will offer better overall sound quality.

How many channels should your amp have?

Car amps come with multiple channels for powering multiple speaker units. Am amp should have at least 4 channels with 2 channels for your front speakers and 2 channels for your rear speakers. However, the number of channels will depend on how many speakers you have in your car’s sound system.

Number of channelsAmps power
1 channel or mono channelA single channel amp can power a subwoofer with a class D rating that uses less power and emits less heat
2 channelsCan power 2 woofers and 2 coaxial speakers
3 channelsWill power 2 speakers and a subwoofer. It has enough power for your front and rear speakers
4 channelsCan power 4 speakers, 2 speakers, and a subwoofer. If you want to add a subwoofer you can also power  4 coaxial speakers and a 1-channel amp to power the subwoofer
5 channelsCan power a subwoofer, 2 front speakers and 2 back speakers
6-8 channelsCan power 3 and 4-way active systems and amp channels for each driver

Where to install the amp

Most car owners concentrate more on the amplifier specs and forget the size of the car or the available space to fit the amplifier. Given that your amplifier will take an external attachment, you’ll need to first decide on where you’re going to place it. Most amplifiers are fitted in the trunk, below the seat, or behind the firewall on the passenger side. You should have enough space to wire the amplifier properly. Amplifiers also come in different shapes and sizes, but the size of the amplifier isn’t directly related to its performance.


When shopping for a car amp you must find one that will help improve the sound quality of your car’s sound system. You also need to consider many factors when trying to match your amp with your speakers which includes not getting an amp with too much power and very little energy. You should also match your amp and speakers with the correct RMS power rating. You also need to ensure that you have enough power for the amplifier if you don’t want to damage your speakers for lack of enough power. Also, ensure the amplifier can have enough space in your car, it’s compatible with your audio system and it has the number of channels you want.


Can an amplifier be too powerful for speakers?

Speakers are limited by the electrical energy they can convert into audio. So if an amplifier produces more power than the speaker can handle, it can cause distortion or clipping and even blow your speakers.

Should my amplifier be more powerful than my subwoofer?

As long as your subwoofer has more power than your amplifier, it doesn’t matter. However, you should be careful about the impedance because if it’s done wrong it can cause damage.

Andrew Gibbons

According to Andrew Gibbons, playing the guitar is fun but it will take a few months before you can come up with a creative expression. Gibbons is a guitar instructor and has been teaching University music programs for over a decade, when it comes to playing the guitar a lot of factors come into play that determines the type of sounds produced. The guitarist must consider the guitar's neck and body shape, weight, and string type, the amp is also a primary determinant of the sounds produced and that is why Gibbons has created extensive excerpts detailing on the delicate topic. Guitarists must also pick a pose, be it the pro, wizard, hipster, or the old master.