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How to Choose The Best Car Amplifier for Your Car

Car amplifiers are designed to improve the quality of sound produced by the vehicle’s audio system. Nowadays most cars are offered with some sort of built-in amps. These amplifiers are normally fixed into the head unit and aren’t external.

Did you know that built-in amplifiers are not as powerful as some people think? Sometimes we end up blaming our speakers if they fail to crank up the volume to our expectations.

If your speakers are the sort that produces the kind of some stodgy and flat music, then there are high chances that the problem isn’t the speakers but the amplifier. External amplifiers are built specifically for those who really care about their car’s sound system. They bring life to your speakers and sub-woofers by creating sharpness and excitement.

Boss audio system amplifier

Why Do I Need an Amplifier?

Yes, some speakers are better off without an amplifier. The question now comes, why add an external amplifier to your car’s sound system? Amplifiers are a very important part of the whole audio system, especially for those who want to breathe life into their car’s sound system. Whether you run your sound system softly to allow for conversation or wide open, an amplifier excites. Let’s look at a few benefits of including an amplifier in your music system.

  • Enhanced sound quality – Adding an amplifier to your vehicle’s sound system will provide you with a better and clean power source that is capable of driving your speakers with much ease.
  • Unlike the built-in amp that comes with the dashboard stereo, external power amplifiers are not limited by the space that is available within your car. This translates to a more defined sound at all volume levels.
  • Best for powering upgraded car speakers and sub-woofers – A factory amp system may not give the best to your upgraded speakers or subwoofers. High-quality aftermarket speakers systems require a higher amount of power for them to deliver peak performance. This can only be achieved best using external amp systems. Subwoofers require more power than factory amp units can provide. It is therefore important to install external amplifiers.

Choosing the Best Car Amplifier for Your Vehicle

You can purchase a car amplifier from local car audio shops, internet outlets such as Amazon and eBay, or big stores. Before buying an amplifier, it is always important that you the different types of amplifiers available in the market. Most important, you should know the right kind of amplifier to choose the best for your vehicle.

Purchasing a perfect amplifier may be overwhelming with the number of options on the market. Whether you’re considering upgrading your existing amp or install a new one, there are certain factors that it is important to pay attention to.

  • Channels
  • Power
  • System compatibility
  • Amplifier class/ Rating​

Aftermarket Car Amplifier Installation

Amplifier rating or class

Car amplifiers are usually categorized based on their ratings. These ratings or classes are related to the features and design of the system’s electronic circuit. The ratings are given depending on certain characteristics that are related to the amplifier’s energy efficiency, sound performance, and operating temperature.

The classes of car amps are Class A, Class B, Class AB, and Class D amplifiers. The following table shows the different classes of car amplifiers and their advantages and disadvantages.

Class A Amplifiers

What We Like

  • Reproduces perfect high-frequency sound

What We Don’t Like

  • High operating temperatures and not energy efficient

Class B Amplifiers

What We Like

  • Low operating temperatures and are energy efficient

What We Don’t Like

  • Sound distortion at high frequencies

Class AB Amplifiers

What We Like

  • Reproduces high-frequency sound
  • Energy efficient
  • Low operating temperatures

What We Don’t Like

  • Peak performance slightly lower than Class A car amplifiers

Class D Amplifiers

What We Like

  • Energy efficient
  • Features low operating temperatures
  • Excellent low-frequency sound reproduction

What We Don’t Like

  • Poor high-frequency sound reproduction

Class AB amplifiers are a super choice because they offer the advantages of both Class A and Class B amps without significant trade-offs.

Class D amps are ideal for low-frequency sound applications.

rockford fosgate


A channel refers to the electronic circuit that is used to provide power to a single speaker in a car’s sound system. Car amplifiers featuring multiple channels are ideal for powering multiple speaker units. The important question is should ask yourself is, what is the right number of channels suitable for your car’s sound system?

The number of channels depends on the number of speakers connected to your sound system. This simply means that each speaker that you need to amplify requires its own channel. If you’re planning on adding a subwoofer to an existing system, a single amp can get the job done.

You can configure some car amps with multiple channels for specific applications. For example, mono amplifiers with class D rating are specifically designed to consume less power and emit less heat when amplifying woofers.

The most versatile units are those with 2, 4, or 6 channels. A car amplifier with two channels can be used to power 2 woofers, 2 coaxial speakers, or can be bridged to run a single sub.

4-channel amplifiers are the best option when you want to add subwoofers to your system and enhance the power directed to the rear full-range speakers. In such a case, it is very easy to run the full range speakers, each with its own channel, and bridge the remaining other 2 channels to power the subunit. You can also power all 4 coaxial speaker units with the same amp and then designate a separate a different mono amp for the sub-woofer.

You should note that component systems are usually more complicated and you may require more than a single amplifier and external crossovers.


Never compromise on power when selecting your car amp units. It is important that you don’t underpower your car’s sound system speakers. Most people tend to make the mistake of purchasing speakers first before buying the amp. It is recommended that you go the other way round.

You should pick the speakers first and then determine the perfect amp suitable to power them. If you’re operating with pre-installed factory speaker units, it is recommended that you determine the RMS value and then select an amp capable of delivering a minimum of between 75 to 150 % of the RMS.

Power is also crucial if you want to operate with the same amplifier that you’re using for powering the speakers. It may be a great deal to bridge 3 channels so as to provide sufficient power required for running a sub but it isn’t always excellent for every situation. If your amplifier is not capable of matching the required subwoofer power, then you may consider going for a separate mono amplifier that can get the job done.

System Compatibility

If you’re planning to design a car audio system from scratch, then you have to buy a head unit with preamp outputs and an amplifier featuring line-level inputs. Installing an unamplified signal to your amp gives you a very clear sound.

Unfortunately, most of the pre-installed factory head units and some aftermarket units don’t come with preamp outputs for connecting to an external amplifier.

If your existing head unit falls within this category, then you should opt for an amplifier with speaker-level units. They are capable of reproducing excellent sounds and it will save you from having to deal with additional adapter installation and wiring.

Aftermarket Car Amplifier Installation

You don’t need to be a rocket scientist to install your car amp unit. It isn’t as hard of a task as you may think. All you need to do is to find the ideal locations to fix the amplifier and the best way you’ll route the wires.

When shopping for a car amp unit, determine the ideal location for fixing the hardware and routing the wires. Because most cars usually don’t come with pre-installed amps, you may be forced to find a place within the vehicle to fit the amp.

With that in mind, it’s crucial that you take some measurements before buying a car amplifier. Some of the most common locations to install an amp include under a seat, in the  trunk, or against the passenger-side firewall.


Selecting the right car amp is important when you want to improve your vehicle’s sound system. You cannot get quality and clear sound from under-powered speakers. Instead, they’ll ruin your listening experience.

Aftermarket full-range speaker units, component speakers, and subwoofers cannot perform to their best capability without a sufficient power supply from the amplifier.

Featured image credit: Pixabay