Every car head unit comes with a built-in amplifier.

However, for the most part these built-in amps aren’t much to write home about.

If you’ve ever cranked up the volume on the stereo and the sound started to distort and lose tone gradually, you'll know what I mean.

The fact that your audio system doesn't receive enough juice to reproduce well-balanced sound is one of the main causes of distortion. The power handling characteristics of your speakers also come into play, but a good amp can do wonders even in a stock situation.

Choosing the best car amplifier for your sound system can be a daunting task. There are a ton of car amps on the market. There are also different factors that you need to pay close attention to in order to make an informed buying decision.

Best Car Amplifiers Reviews

1. Rockford Fosgate R300X4 Review

2. Planet Audio AC1200.4 

Affordable and flexible enough to work with both stock and aftermarket speakers and headunits, the Planet Audio AC1200.4 is an excellent choice for set-ups that need an amplifier but don’t necessarily need one that’s high-powered.   

It is made out of high-quality materials with high and low level inputs. It also has a fixed high-pass crossover and a variable bass with low-pass crossover. Lastly, it’s backed by a 6-year platinum dealer warranty.   

With a warranty this long, you can pretty much guarantee that the manufacturers are confident in the quality of their product.  

3. Rockford Fosgate R500X1D Review

The Rockford Fosgate R500X1D is one of the best mono channel amplifier on the market. It uses efficient class D circuit topology, and it's rated for 500 watts RMS at 2 ohm.

It would be a great investment for anyone who's looking for a separate amplifier to drive a powerful subwoofer.

The R500X1D features a heavy cast aluminum chassis which efficiently disspate heats from the internal components of the amplifiers, ensuring reliable, long-term play.

This mono-channel amp is fitted with built-in sensors that keep track of the output current and power supply temperature. Ensuring that plunging subwoofer impedances (they change constantly during play) or even a short circuit won't do any damage.

In other words, it has over current and short circuit protection.The R500X1D amp includes on-board Punch Bass and remote Punch Level Control.

4. Pioneer GM-A5602 Review

5. Rockford Fosgate P1000X2 Review

If you're looking for a powerful 2-channel amplifier and don't mind shelling out a few extra dollars, then the P1000X2 by Rockford Fosgate is another great 2 channel amplifier to consider.

The Punch P1000X2 amplifier is a very well-engineered amp.

The P1000X2 amp features a bass and treble boost , in case you want to add a little boom and sizzle back into the mix. Rockford Fosgate isn't afraid to push the envelope.

They set the P1000X2 amp for optimum performance. They step away from the crowd with their C.L.E.A.N. technology (Calibrated Level Eliminates Audible Noise) — which ensures that your music sounds as clean and powerful as possible.

If that blue light turns red while you're playing your music, the amp's telling you that your source is distorting, and therefore, you should turn it down.

The P1000X2 amp relies on a thermal Management system that uses forced air to dissipate heat evenly across the internal component of the amp through the high-mass heatsink.

6. Rockford Fosgate PBR300X4 Review

You don't have to feel left out in case there isn't enough space inside your vehicle to accommodate a large amplifier, because Rockford Fosgate has got you covered with a great ultra-compact 4-channel amplifier.

You won't believe how small and powerful this amp is — It's literally the size of your hand.

It can put out 75 watts RMS to each of your front and rear speakers, giving you enough power to fill your car's interior with great-sounding music.

The PBR300X4 uses the Dynamic Thermal Management cooling system. It has a selectable high- and low-pass filter, as well as preamp and speaker-level inputs.The downside, however, is that it's non-bridgeable.

7. Alpine PDX-V9

Have you ever heard of the saying, “small but powerful”? Because, if not, then the Alpine PDX-V9 is a good example of it.   

Measuring just right around the size of a standard notebook, this class D amplifier is compact enough to fit inside cramped spaces. However, despite its diminutive stature, the PDX-V9 can offer 100 watts to each of front and rear speakers with 500 watts to spare for a separate subwoofer.   

Because it is a class D amplifier, the PDX-V9 runs relatively cool. You can also stack it on top of each other since it’s so small and also virtually overheat-proof as long as it’s properly set-up.   

Another added benefit is the front-facing controls that make it easy to tune the amp even when you’re stacking multiple units on top of each other.  

Just be careful when bridging this with another amplifier. Don’t set it up yourself if you don’t know how. Otherwise, you’ll end up causing permanent damage to your amplifier if not your car’s entire audio system.  

8. Kenwood KAC-M3004 

Don’t let the compact looks of the Kenwood KAC-M3004 fool you. This 4-channel amplifier can power up to 50 watts RMS each channel. It can even be bridged to run in 2-channel mode to send 150 watts per subwoofer for even more power.

Also, because it is so compact, you can install it pretty much anywhere, even in motorcycles.   

In terms of durability, the amp is well-protected from moisture because of its conformal-coated circuit board.

Meanwhile, the amp has power and power control connections with two pairs of RCA inputs. It can even be connected to units without preamp outputs, such as factory headunits.   

Powerful and small, the only drawback to the Kenwood KAC-M3004 is its high asking price.   

But, you do know what they say, right? You get what you pay for.  

9. Rockford Fosgate TM400X4ad 

A Class A/D car amplifier, the Rockford Fosgate TM400X4ad combines a compact build with a very heat-efficient design as well as the ability to provide tons of power consistently. It uses what Rockford Fosgate refers to as the C.L.E.A.N setup, making it very easy to install even for DIY enthusiasts.   

The three-stage thermal lock extrusion is backed with a dual cooling fan for extreme cooling efficiency. This design also minimizes any audio distortion. More importanly, you can use this amplifier pretty much on any vehicle. This includes boats, because it is built with added protection against dust, dirt, corrosion, and the sun’s UV rays.   

The only issue here is that it’s only capable of providing 400 watts of total power.   

For the price, that’s not a lot. But, if you’re looking for a high-quality car amplifier that you can use in any vehicle you might have, the TH400X4ad makes for an excellent choice.  

10. Kenwood KAC-7005PS

The KAC-7005PS is one of the best car amplifier that Kenwood has to offer. 

This 5 channel amp can take care of your entire car audio system's power requirements. At 4 ohms, it can drive both your front and rear speakers with 40 watts RMS each, then factor in up to 300 watts RMS for your subwoofer. 

If you've got a powerful pair of speakers you want to drive, you can bridge this amp into 3-channel mode and send 100 watts RMS to each of your speakers, along with that 500 watts of bass power. 

The Kenwood KAC-7005PS features a rugged cast-aluminum heatsink and a cooling fan to keep the amp running at optimal temperatures, even under excessive use. This versatile, tiny 5 channel amp can fit pretty much anywhere. 

It features separate adjustable crossover filters for the front, rear, and subwoofer channels, as well as a bass boost, so you can dial in exactly the tone you want. 

All in all, the Kenwood KAC-7005PS is a great class d amplifier to consider if you want to avoid the hassle of installing multiple amps, and running cables. 

Why add an amplifier?

Do you want to crank it up and avoid sound distortion? Do your newely installed speakers require more power than what your stereo is capable of putting out? Are you looking to add a subwoofer to your sound system?

Whichever is your case, amplifiers are definitely part of the picture whether you're looking for sound volume or sound quality. A powerful amplifier will breathe life into your entire stereo system, allowing it to reproduce crystal clear and detailed music.

Here are a few of the main benefits of adding an amp:

Better sound quality

Underpowered speakers are one of the most common causes of low sound quality. Having power needy speakers paired up to a factory-installed or even an aftermarket receiver isn't a wise idea. Unlike amplifiers built into subwoofers, external amplifiers have enough power. That means your music will sound cleaner and more defined at all volume levels.

Enough Power for Aftermarket Speakers

A factory-installed head unit may not do justice to your these speakers. Most of these speakers are louder and more powerful than the factory-installed ones, and thus require more power for   optimal performance.

Powering a subwoofer

Subwoofers require significantly more power than a brand-name or factory-installed stereo can provide, that's the reason why a separate amp is a must.

Types of Car Amplifiers

External amplifiers are categorized by the number of channels, or speakers they can power simultaneously. There are mono-channel amps, and multi-channel amps. Multi-channel amplifiers come in the 2-channel, 3-channel, 4-channel, 5-channel, and 6-channel variety.

The difference between all of them is pretty self-explanatory. However, we can't stress enough how important it is to pick up the right car amplifier to avoid installation problems and the need to buy additional equipment down the road.

Monoblock, 2-channel, and 4-channel amps are the most common amplifiers on the market. Bear in mind that just because an amplifier is branded as “2-channel” doesn’t mean it’s only capable of powering 2 speakers.

In theory, it’s possible to have as many speakers as you want paired with a 2-channel amp, it will just change the impedance (ohms) and change how the power is distributed between the speakers.

That said, and even though it’s possible to wire multiple additional speakers, it’s most common to use a monoblock app for a subwoofer, a 2-channel for 2 speakers, 4-channel amplifier for 4 speakers, and so on.

Knowing the number of channels required is the first step to choosing an amp; for instance, a system with four full-range speakers and a subwoofer would require a five-channel amp, or a four channel-amp for the speakers and a separate monoblock amp for the subwoofer.

Mono-channel Car Amplifiers

A mono-channel car amplifier is an amplifier with a single channel. These types of amplifiers are designed specifically to power a subwoofer. If you're building your car stereo system from scratch, and bass is high on your list, then consider combining a mono-channel amplifier with a car subwoofer.

Two-channel Car Amplifiers 

These amps have two distinct channels. They're usually used to power two speakers/subwoofers. A two channel amplifier is perfect for a vehicles with only front door speakers such as trucks.
A two-channel amplifier can be bridged to power a single subwoofer.

Bridging an amplifier means combining the available channels into one channel with half the ohm (Ω). The purpose of bridging an amp is to increase its power output. A two channel amp can be bridged to one channel, and a four channel amp into two channels.P.S : Not all multi-channel amps can be bridged.Bridging an amplifier isn’t ideal in every situation.

Three Channel Car Amplifiers  

These amps combine two amplifiers in one. Typically, class AB and class D circuitry are built into these amps (more on this later). A subwoofer can run off the class D mono-type, while two speakers can run off the other two channels.

And since these sets of circuitry are different and separate from each other, the three channels cannot be bridged. Three channel amps are a practical solution for vehicles with very limited space for a second amplifier, like small trucks or two door  coupes.

Four Channel Car Amplifiers 

Four channel amps offer greater flexibility and can be configured in a variety of ways. For example a four channel amplifier can be used to drive four (front & rear) speakers, or two speakers and one subwoofer, assuming that two channels are bridged.

Five Channel Car Amplifiers

These amps are similar to three channel amps. They combine two amplifiers in one. A mono channel amp to power a subwoofer, and a separately circuited four channel amplifier to drive front and rear deck speakers. Five channel amps allow for even greater flexibility than four channel amps.

They're also quite easier to install. These amps are practical and convenient to use in situation where a subwoofer and both front and rear speakers are required, such as in a sedan or small SUV.

Six Channel Car Amplifiers

These amp are less common, but still used particularly in large SUVs. They're capable of powering up six speakers or four speakers and subwoofer.

To sum it up, A mono-channel car amplifier is perfect for powering a subwoofer, but you can not use to power a pair of speakers. Two channel amps can be used to power a pair of speakers, and can also be bridged to drive a subwoofer. Amps with four or more channels are similar to two-channel amp, but offer greater flexibility.

P.S : If your head unit isn't equipped with pre-amp outputs, look for a car amplifier that has speaker-level inputs.

How to choose a good car amplifier

Picking the right car amplifier is the key to improving the sound quality of your car audio system. Your speakers and subwoofers will not perform up to their potential without an adequate power supply.

Besides figuring out the number of channels that your future amplifier must have, there are various other factors that you should take into consideration including amplifier class, bass boost, filters, inputs, peak power, and RMS power.

Amplifier Class

Amplifiers fall into four different classes : A, B, AB, and D. These classes relate to the internal design and amplifier’s electronic circuitry. The table below describes the advantages and disadvantages of each class.

Class A  :

Class A amps are desirable for their high sound quality, but they're inefficient and run very hot because there is a large amount of current flowing through the output transistors even when there is no audio signal.

These amplifiers feature the highest sound quality since their transistors never turn off, therefore there is never an interruption of signal.

However, the current flowing through the output transistors constantly (even when there's no audio signal) is what causes the amp to heat up unnecessarily, and "waste" input energy.

Class B :

Class B amplifiers offer a significant improvement over Class A amps. They're substantially more efficient than their Class A counterparts (about 50% to 70%). Class B amps are equipped with two transistors. One transistor is used to reproduce the top half of the waveform, and a second transistor is used to reproduce the bottom half of the waveform. In a class 'B' amplifier, no current runs through the transistors when there's no audio signal, making these amps more efficient. However, that short pause in the signal when switching between the transistors causes a bit of noise which is referred to as crossover distortion. Class B amps exhibit more crossover distortion than any other class amp.

Class AB :

As the name implies, class AB amps combine the benefits of both class A and class B amps. Class AB amps are similar to class B amplifiers. They both use two groups of transistors.

However, class AB amps are designed to allow minimal current to run through the output transistors even when there's no audio signal, thereby eliminating crossover distortion that occurs when switching between transistors as is the case with class B amps.

A class 'AB' amplifier is much more efficient than the class 'A' but without the possible distortion of the class 'B'. That's the reason why these amps are considered to be the best compromise.

Class D :

Class D amps are quite different from the other amplifiers. Their output transistors are used as switches to control power distribution — the output transistors are either completely turned on or completely turned off. In other words, they're operating in switch mode.

That's the reason why class D amps boast higher efficiency rating, produce less heat, and draw less current than class AB designs.

The downside, however, is that they produce higher distortion than class AB amps due to rapid switching on and off of the transistors. Luckily, this distortion is easily filtered and removed by a low-pass filter.

Bass Boost

Bass boost is a type of electronic circuitry built into some amplifiers. It increases low-frequency sound reproduction (aka bass) in dB increments (ie. 0-12 dB at 45Hz).

Some amps allow you to adjust bass boost on the go. If you do choose to boost the bass, it is recommended that you compensate for this boost by re-adjusting the amp's gain, so you can prevent your amp from clipping and distorting.

Car Amplifier Filters

Filters are electrical circuits used in amps for the purpose of avoiding sound distortion. Car amplifiers are equipped with two types of filters : low-pass and high-pass filters.

Low-pass filters send low-frequency tones (lows or bass) to the subwoofers and keep them from producing highs. Likewise, high-pass filters send high-frequency notes (highs) to the tweeters and prevent them from reproducing lower tones.

Car Amplifier Inputs

Car amp inputs transmit signal from your car's in-dash head unit to your car amplifier. Most aftermarket head units are equipped with RCA preamp outputs that allow you to connect the receiver to the amplifier directly.

However, some factory-installed stereo do not have pre-amp outputs, which means you can't connect the amp to the receiver directly. If that's the case with your setup, then consider an amplifier with speaker-level inputs.

RMS Power of Car Amplifiers

RMS (Root Mean Square) refers to the amount of continuous power, measured in watts, that an amplifier can produce. When you're looking for a car amplifier, you'll notice that manufacturers like to brag about the peak power ratings of their amps.

However, the peak power rating isn't an accurate indicator to take into consideration. It only tells you the maximum wattage an amplifier can deliver as a brief burst during a musical peak. In other words, peak power is not sustainable and can only be achieved intermittently.

The RMS rating, however, is more significant and more accurate.

How to Install a Car Amplifier 

Conclusion 

Now that you know what the best car amplifiers in 2020 are, please let us remind you of something that’s critically important -- don’t try to install these car amplifiers yourself if you have little to no prior experience.   

While some of these amplifiers can be installed without professional help, you’ll still want to ask a professional for their advise on how to choose the right wire gauges and to check if your amplifier can support your car’s audio system.   

Lastly, once installed, don’t go blasting the volume all the way up just yet! You’ll need to tune your stereo system first after installing it to minimize any chances of a shorted fuse.   

But once you got these babies tuned, crank that volume up and have at it! You’ll feel those massive gains instantly!