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Best 4 Channel Car Amplifier (Review & Guide)


Sometimes you have a car stereo that does not produce the required high-quality sound and volume. If your car has rear and front speakers, then the solution to your issues can be searching for the best 4-channel amplifier. With the 4-channel car amplifiers, you will be assured of getting premium sound from the back and front speaker combinations.

The 4-channel amplifier will still work for you even if you have only a subwoofer and two speakers. Additionally, since these external amplifiers are compact, it makes its installation easy. Since there are so many amplifiers, the guide below will uncover the best 4-channel car amplifiers.

Top 10 Best 4 Channel Car Amplifier For Sound Quality

RankingsNamePrice and More Details
Rockford Fosgate P600X4 Punch – Best 4-channel AmpClick Here
Alpine MRV-F300 4-Channel Car Amplifier – Best Sound Quality Click Here
Rockford R300X4 Prime 75 Watts x 4 @ 4-Ohm Car AmpsClick Here
Boss Audio System R1004 – Best Low Budget Class A/B Car AmpClick Here
Pioneer GM-D8604 – Best 4 Channel Amp For The MoneyClick Here

These reviews will get to understand the kind of 4-channel amplifier that might be good for you. Worth nothing, you will know what of the things you can consider when buying the best 4-channel amplifier. Below are some of the top 10 best 4-channel car amplifiers that you should try out.

1. Rockford Fosgate P600X4 Punch 4 Channel Car Amplifier

Rockford Fosgate P600X4 Punch 600 Watt 4 Channel Amplifier

Key Features

  • 75 watts RMS x 4 @ 4-ohms per channel
  • 300 watts RMS x 2 bridged amp
  • Best high quality class A/B amps
  • Calibrated audio system noise levels
  • Heat sink design keeps your system cool

The Rockford Fosgate P600X4 is one of the best 4-channel amplifiers that produce 150W into the four channels at 2-ohms resistance. Most importantly, it is a bridgeable car amplifier that best suits a 4-way or 3-ways full-range system that pairs well with subwoofers. Arguably, the amplifier can be combined to offer an immense output.

The amplifier is also equipped with a state-of-art auto turn-on output that eases the setting up process. It turns on automatically once the voltage runs through. Nevertheless, this Rockford Fosgate amplifier has an automatic short circuit to prevent accidental burn out. Its customized aluminum heat sink prevents it from heating up at high temperatures.

Additionally, the amplifier comes with an input clip indicator and an Optional remote Punch Level Control. The amplifier delivers a lot of bass with a sensitivity level of 18dB and a frequency of 45Hz. Nonetheless, the Rockford Fosgate amplifiers’ RCA inputs accepting both low and high-level audio signals required a signal converter.

2. MTX Audio Thunder75-4 Thunder Series 4-Channel Car Amplifier

MTX Audio THUNDER75.4 Thunder Series Car Amplifier

Key Features

  • 2 Ohm stable 100 W x 4 channel amp
  • 175 Watts RMS x 2 per channel amps
  • Class A/B topology amp sound system
  • Easy to install 4 channel power pack
  • Triple car stereo short circuit protection

The MTX Audio Thunder75-4 is one of the best 4-channel amplifiers that deliver RMS power of 100W at 2-ohm and 75W at 4-ohms. The amplifier features the best soundscapes with a frequency range of 15Hz to 25kHz. Even at the maximum power output of 400W, you will get control of any of your car speakers since it is universal.

Not only is this car amplifier lightweight, but it is also compact and powerful. It has been designed to be surface mounted easily, even for cars that have smaller spaces. Moreover, the surface mount design enables it to handle vibrations and enhances easy hookups. It features class A/B topology that allows it to provide the best sound output.

The amplifier has an extruded aluminum heat-sink that enables it to stay cool even when you use it for long hours. It also features advanced triple circuit protection that ensures that the amplifier will never burnt-out. Additionally, the amplifier’s terminal block uses set screw connectors for both ground/power and speakers, making it easier to make strong connections.

3. Rockford Fosgate R300X4 Prime 4 Channel Amplifier

Rockford Fosgate PBR300X2 Punch 4 Channel Amp

Key Features

  • 75 watts RMS x 4-Ohms power per channel
  • Rockford Fosgate unique class B/R rail technology
  • Expect high sound quality input levels with this amps
  • Easy to install compact MOSFET design output
  • Full-range amps that won’t hurt your electrical system

The Rockford r300x4 prime amplifier is small in size as it measures about 2 inches by 4 inches by 7 inches, making it easier for you to mount it under the car seat or dash without causing any inconveniences. It can deliver 75W for every channel at a resistance of 4-ohms.

The amplifier features a Butterworth crossover for filtering frequency. It also has a series of high-levels of inputs. When you turn the amplifier, the lead illuminating lights indicated blue. Conversely, the lights will illuminate red when the amplifier’s internal components are too hot, the low impedance is detected, or the amplifier experiences a short circuit.

Furthermore, the auto protection feature can shut it down for sometime before it cools down. As a result, you can mount it under-the -car seat since it will overheat. Additionally, the amplifier uses a multi-layer insulated metal substrate that operates with minimal resistance. The amplifier has an onboard equalization circuit that assists in correcting noise cancellation (acoustical deficiencies).

4. Alpine KTP-445U 4 Channel Power Pack Amplifier

Alpine KTP-445U 4-channel Power Pack Amplifier

Key Features

  • Amp that provides 45 watts per channel at 4 & 2-Ohm
  • 90 watts RMS x 2 channel power bridged amps
  • Higher sound quality out of this class D amp
  • Easy to install with an aftermarket head unit
  • Unique harmonic distortion with a clean signal

Sometimes, instead of replacing your car’s entire stereo system, all that is required is only a little power boost. In such cases, the Alpine KTP-445U amplifier promises to assist all underpowered heat units to have extra power. The amplifier has the letter “U,” which implies that you can pair with any heat unit model or brand.

This compact amplifier uses state-of-art design to produce high-quality sound. It allows for under-the-seat mounting since it does not overheat. The amplifier is rated class D. It provides 45W of RMS power for each channel. You can also bridge it to deliver 90 watts x 2 at 4-ohms and 45 watts RMS x 4 channels.

Additionally, this Alpine KTP-445U super-compact car amplifier can easily fit behind the dash or glove compartment. It also has additional features such as super-low THD, configurable inputs, adjustable and independent low and high pass filters. The amplifier has RCA inputs with a sensitivity that ranges between 0.2V to 4V.

5. Boss Audio R1004 4-Channel Compact Amplifier

BOSS Audio Systems R1004 4 Channel Car Amplifier

Key Features

  • 100 Watts per channel at 2-ohm of power
  • Higher sound quality RCA input adapters
  • Class A/B amp with enormous power flow
  • Easy to install with enhanced sound efficiency
  • Amazing 6-year manufacturers warranty

With a MOSFET power supply, this Boss Audio amplifier can comfortably deliver a power output of 100 watts. Although the power may appear to be small, it is better for many cars than junky systems. Every channel can produce 38W. Unfortunately, you cannot bridge the amplifier.

This Boss Audio amp is a class AB 4-channel car amplifier with high-quality linear circuits that can cope with high power outputs. It comes with a variable low pass filter that enables the user to control any condition your car subwoofer is exposed to. Additionally, it has low and high-level inputs that assist it in achieving optimum performance.

Furthermore, you can control the sound levels of the subwoofer using a wired-in remote. It also has a bass boost function that adds 18 decibels. Notably, the car amplifier has an automatic shut-off protection feature that prevents it from short-circuiting. The protection mechanism constantly monitors connected speakers to detect electric failures and heat issues.

6. Pioneer GM-D8604 4 Channel Bridgeable Amplifier

Pioneer GM-D8604 4 Channel Bridgeable Car Amplifier

Key Features

  • Amazing 130W x 2 channel power bridged
  • Maximum power of 520 watts with this amp
  • 94 dB signal to noise ratio and 4 RCA inputs
  • Adjustable crossover with 12 dB high pass slope
  • Easy installation with an aftermarket head unit

With this compact 4-channel amplifier, you will not face any challenges finding a space to install it. It can deliver 100W of power for every channel resistance of 4-ohms. It is also bridgeable. Additionally, the amplifier has an advanced circuit design that assures that it will be protected from short circuits, low voltage outputs, and power surges.

In case you wish to pair the front speakers of your car with a subwoofer, this 4-channel amplifier is the best option for you. Therefore, you can combine the two dedicated lines at the back to efficiently power your car subwoofer. As powerful as the Pioneer GM-D8604 amplifier is, it is still very compact.

It has a variable high and low pass filter that enables you to control any condition your car subwoofer is exposed to. Additionally, the Pioneer GM-D8604 amp has low and high-level inputs that assist it in achieving optimum performance. The speaker level inputs are highly versatile, making it possible to fit with any car subwoofer systems.

7. Planet Audio AC12004 4 Channel Amp for Sound Quality

Planet Audio AC1200.4 4 Channel Car Amplifier

Key Features

  • Superior 1,200 Watts of max power amp
  • Incredible 450W x 2 RMS of power bridged
  • These amps allow full control of your sound
  • System is designed with class A/B topology
  • Platinum 6 year warranty offered by dealer

Planet audio ac12004 is a clad D amplifier that can easily fit into the tight space behind your dash, or you can mount it adjacent to your main car amplifier. The amplifier produces powerful sound due to its power output capabilities. In this case, the amplifier is equipped with a MOSFET power supply system to produce a maximum power of 1200 Watts.

At 4-ohms, the amplifier can deliver 113W from every channel, and at 2-ohms, the amplifier delivers over 200 watts per channel. It is also possible to bridge the amplifier to get a higher output of about 450W for two channels at 4-ohms. With a frequency range of 10 to 50 kHz, low and high-pass filters, its signal can remain stable and clear.

The amplifier is rated as class A/B. It comes with impressive amplification abilities. Notably, it has a black anodized outer shell that is designed for maximum heat dissipation. It also includes variable bass boost filter, variable high pass, and low pass filters. With this amplifier, you will experience minimum distortion at all volume levels.

8. Kenwood KAC-M3004 Compact Digital Amplifier

Kenwood KAC-M3004 Compact 4 Channel Digital Amplifier

Key Features

  • Amp provides 50 watts RMS x 4 at 4-Ohms
  • Best class D 4-channel amp for sound quality
  • Comes with a special AWG16 MOLEX connector
  • Delivers unique heat sink sound system design
  • Allows 4Ω to 8Ω bridgeable speaker connections

The amplifier provides a maximum power output of 600W. The impressive power output is achieved by venting out 50 watts from each channel at 4-ohms and 75 Watts per channel at 2-ohms. Kenwood KAC-M3004 is rated as a class D amplifier with a 90% efficiency rating. You can bridge this amplifier to a 2-channel mode so that it delivers 150 W for every subwoofer.

Its chassis is made of an aluminum casing that houses circuit boards for maximum protection. Its variable crossover ensures that you get more power. Additionally, the amplifier stays cool when used as it experiences minimal heating. The amplifier is equipped with 2-pairs of RCA inputs so that you can easily connect the stereo RCA patches at the head unit.

The amplifiers use conformal coated main Printed Circuit Boards(PCBs) that provide extra layers of protection. Your amplifier will be protected from damage through the PCB boards since it will make it moisture-proof. It also has an automatic turn-on sensing signal. It has a simple and efficient design that enables it to suit any car.

9. Alpine MRV-F300 4 Channel Car Audio Amplifier

Alpine MRV-F300 4-Channel Car Amplifier

Key Features

  • Expect standard 75W x 4 (for each channel)
  • Thermal management processors for heat sink
  • Class D amps that provide 80% operating efficiency
  • Wide frequency feedback modulation design
  • Unique bass EQ and low impedance power

The alpine MRV-F300 is a class D amplifier with state-of-art power output. Worth noting, the amplifier delivers 50 watts RMS x 4 channels at 4-ohms resistance and 75W into the four channels at 2-ohms resistance. When bridged, it delivers an output of 150 watts that enables you to enjoy listening to your favorite music.

The amplifier has a unique enhanced shutdown performance that works efficiently to keep it safe. In this case, instead of the usual shutdown, the amplifier will continue playing music at the lower output until its power stabilizes. Therefore, you will not worry that the amplifier will burn out. As a result, individuals who use the amplifier will be assured of stable performance even when the amplifier is exposed to strenuous conditions.

Conversely, Alpine MRV-F300 provides the best bass boost for speaker level inputs, pre-amplifier, low-end efficacy, and MOSFET power supply. Moreover, you will be assured of easy installation with its small size even if your car has confined space. However, its cover has a blue light that can be annoying, especially when driving at night.

10. Rockville DB45 1600 Watts RMS x 4 Multichannel Amplifier

Rockville dB45 3200 Watt:1600w RMS 4 Channel Amplifier

Key Features

  • Up to 1,600 watts x 2 channel of bridged power
  • CEA compliant with Rockford Fosgate and more
  • Amps provide full circuit protection and soft start
  • Best adjustable crossover and LED indicators
  • Expect 10Hz to 50Hz frequency response with this amp

The Rockville DB45 amp is one of the best high voltage 4-channel amplifiers designed to handle power well. It has an IC-controlled circuit with a peak-limiter that ensures that the audio sound delivered is not distorted. Nevertheless, it provides a maximum power output of 3200W and RMS power of 1600W.

Although the amplifier is compact, it is ideal for all kinds of cars. The amplifier is classified under class AB since it provides high efficiency. Notably, the amplifier has incredible power handling mechanisms. In this case, it is equipped with a MOSFET circuitry that guarantees high-quality music without any distortions or noise. Moreover, it has a 12bD octave crossover equipped with differential circuitry. Additionally, the car amplifier has high and low-pass filters with a frequency response ranging from 10Hz to 50kHz.

The Rockville dB45 car amplifier is designed with state-of-art technology so that you enjoy using it. It has LED indicators for indicating the delay, soft start, mute, and mode system. It also has a fully functional remote controller and backlight light so that you can easily use the amplifier.

Car amplifiers play the roles in improving the audio outputs of the car audio. There are two main kinds of amplifiers in vogue today. These are the 4-channel and the 2-channel, respectively. In our discussions here, we shall peek into these kinds of amplifiers and everything that pertains to them.

Extra Infinity REF-704A 400 Watts – Best 4-Channel Amp For Marine Audio

Infinity REF-704A 1000 W Peak 4 channel amp

Key Features

  • Provides 70W RMS x 4 of power handling
  • Best aesthetic design amp on the list
  • Marine-grade amp suitable for boats and cars
  • Compact size for ease of installation
  • Design to withstand harsh weather conditions

This is a weather-resistant power amp that is great for use in the indoor and outdoor locations pretty fine. At the same time, it manages higher performances by virtue of converting the audio outputs exceptionally fine. Particularly, it delivers impressive power that is unparalleled by other amplifiers.

You will mainly find it useful for your outdoor applications as it is scarcely hit or destroyed by severe weather. It stands apart from the other 4-channel amplifiers in the sense that it can also support five outputs. That, of course, makes it quite useful for large-scale engagements and applications.

Its makeup also incorporates the most recent amplifier topology. Among this topology are the low, all, and high pass crossovers. They let you vary the frequencies as per your unique system tuning needs. What’s more? It pairs and works alongside the Infinity marine products well. That also extends its coverage immensely.

Tip: The JL Audio brand designs great car stereo speakers, amps, and subwoofers.

Best 4 Channel Car Amplifier Buying Guide

To get your hand on the most suitable 4-channel car amp for you, there are some factors you have to consider. That is given the highly diverse nature of these items, coupled with the many players who are engaged in their production and distribution.

This buying guide will help you identify what to look for when trying the get the best 4-channel amps for your speakers. When you’re trying to combine your first car audio sound system, there are a few key points to understand.

First, you should decide what type of speakers or subwoofer you want to add to your car audio system. Although the amplifier is the most important component, the total amount of speakers would determine the power that you need and the number of channels also.

What to look for when buying a 4-channel car amplifier

Once you have identified the number of speakers, you are now ready to choose the best car stereo amplifier for your system. Below are the factors to look out for when buying 4-channel car amplifiers:

Watts per Channel

This refers to the amount of power that the amplifier is able to provide to the speakers via each output channel. A channel basically attaches to one speaker at a time. A higher notation infers a more reliable amplifier and vice versa. You have to mind your utility expenses also as a higher rating infers a higher consumption of power.

Frequency Response

It is the measure of the frequency of the output sound versus that of the input. This metric forms the core of the amplifier as it forms the primary role of amplifying the audio output. You have to be sure that this measure is not only high but also variable for your proper workouts.

Heat dissipation or heat sink

In the course of tackling the task of amplifying the audio outputs, these appliances do sustain lots of heat. If and when this is left to go on unabated, the pieces of equipment may be damaged considerably. A way out should and must be found. The heat dissipation mechanism it is.

Low pass filters

Once in a while, frequencies that are higher than average are often produced by the gadget. These frequencies are technically referred to as noise. They do compromise the quality of the audio system output considerably. To combat them, the amplifier you have in mind has to possess low pass filters.

Power Rating

The peak power rating describes the sum total electrical power that the machine requires to operate normally and seamlessly. It is calibrated in the packaging and the main body of the machine. You have to see to it that you settle on a machine whose rating is affordable for you.

Amp Speaker Level Inputs

Just in case you are intent on attaching and using a speaker as well, you have to care for the amp level inputs. You will have to watch out for the amp level inputs as well. The inputs are the ones that accept the speakers and regulate the values of the audio inputs appropriately.

Benefits of using a 4-channel amplifier

Choosing a 4 channel amp with a low signal to noise ratio will allow you to have a better listening experience. A typical 4-channel amplifier is beneficial in the following main ways:

Boosts the Audibility of the Audio Output

The amplifiers play the primary role in boosting the audibility of the audio output of the speakers. That is given their critical role insofar as upping the voltage levels is concerned. By doing this, they minimize the over-consumption of power yet, at the same time, manage better outcomes overall. A 4 channel amp would also have a better signal to noise ratio.

Minimizes Strains and Ambiguities

By upping the volume of the sound output, the amplifiers also minimize the strains and the ambiguities that come along. Simply put: you get to hear the sound output as is rather than struggle to make meaning of the audio outputs. That, of course, leads to better listening on your part.

More Power Per Channel

Most of the 4 channel amps previously listed on this buying guide, like the Rockford Fosgate P600X4, also come with 75 watts x 4 out of 4 channels at 4-ohms. If you are trying to power up your four front and rear car stereo speakers, any amp in this list would be a good set up.

In the future, if you’re trying to add a subwoofer to your car stereo system, then you would probably want to get a 5 channel amp. The industry standard when it comes to a 5 channel amp is around 75 watts x 4 and between 100 watts to 500 watts on the filth channel for the subwoofer.

Tip: Most users find that 2 channels are not enough and later have to upgrade to a series 4 car amps.

Difference between class A/B amplifier and class F/D amplifier

These two classes of amplifiers differ in the following regards:

Operational Methods

The class AB incorporates the traits and characteristics of the individual classes of A and B. Full range class D amps, on the other hand, operates on its own, without any input from the other classes. You may nonetheless gain more from the former as it is more comprehensive than the latter.


Generally, Class AB is mainly applicable for the home theater systems as it is able to take on the sophisticated sound systems well. You will find class D amps, on the other hand, great for the public address systems due to the ability to generate truly high loud sounds. Also, you find that for bass sounds engineers typically prefer a class d amp.


Let’s take a deep look now at some of the frequently asked questions with regards to this particular topic:

Are class AB amps the best for sound quality?

YES, it is! This class provides a mix of great sound and power efficiency. The end result of this is unparalleled sound quality and output. You have it for the taking if you want to accrue the most audible and reliable sound outcomes that may be accrued at any given time.

Owing to the quality sound output it generates, this kind of amp is great for the home theaters and the high fidelity sound systems. These include the high-end car stereos and musical appliances that are generally more complicated to handle and engage. They are truly the best in the meantime.

What is a bridgeable amplifier?

Bridging refers to joining two or more channels of an amplifier and using the same to drive towards a common load. The purpose of this common practice is to generate a sound output that is louder and of higher quality than that which may ordinarily be the case.

It hence goes that a bridgeable amplifier is one that allows for the interconnection of the two or more channels. Not all amplifiers are like this one. If you are intent on bridging the various channels, you must see to it that the one you have in mind allows for the attainment of this eventuality.

What are the best 4 channel amp brands?

There are a ton of amp brands to choose from. From our experience and talking to some of the industry-leading sound engineers, we found that the brands that produce the best amps are the following:

  • Rockford Fosgate
  • Kenwood
  • JL Audio
  • Alpine
  • Boss Audio

Although we did not include an amp from the JL Audio brand, we still consider them one of the top industry leaders when it comes to audio systems. Also, this amp buying guide is Taylor for those looking for an economical solution when it comes to finding the best 4 channel amp.

Difference between a 4-channel amp vs. 2-channel amp?

The following are the common differences between these two amperes:

Number of Channels

These two amplifiers differ insofar as the number of channels they may accommodate is concerned. The four-channel amplifier, as its name implies, is able to accommodate four channels and hence send the audio output to four speakers at a time.

Its two-channel counterpart, on the other hand, can only work alongside two speakers or outputs. However, some bridgeable 4-channel amps will allow you to connect the front and rear speakers into a single channel.

To get the best sound out of your amp, you should stick to one speaker per channel. It allows the amp to provide more power to each speaker. Hence you will get much better sound quality and an overall much better listening experience.

Quality of the Sound Output

They also differ in the quality of the sound output they manage to give off. A four-channel amp typically comes with more max power outputs than the two-channel counterparts.

Similarly, it also consumes a higher degree of energy input. That is understandable owing to its extra power to blast. If your set-up is four speakers and bass, a 5 channel amp would be your best bet.

Tip: Overall, a 4 channel amp will allow you to have a much cleaner set up than a 2 channel amp.


WOW! Our insight into the 4-channel car amplifiers comes to an end there. We now hope and pray that you have gained the insight and the head start you need to appreciate these appliances better and even make a more enlightened purchasing decision. What are you waiting for? Is it not proper for you to move speedily and acquire one for yourself?

Unless you buy a high-end car, you cannot enjoy the high-quality you need since even the factory stereo may appear to be subpar. However, as demonstrated above, there are so many 4-channel amplifiers that enable you to overcome such issues. However, you must figure out the option that you think is best for your car.

You are now ready to choose the best car amplifiers with 4 channel that fits your needs. Any amp in this list will do the trick, so go back and check the list again. Choose an amp that has an affordable price and that it can power up your speakers.

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