Choosing a 4 channel amp for your car can be a really daunting task. With so many options available, each with its own long list of technical specifications, knowing which amp will give you great sound can be difficult. That’s where we come in!
We’ve read hundreds of reviews, talked to some real audiophiles, and spent hours listening to amps, all so we can tell you that if you are looking for a 4 channel amp, the Pioneer GM-D8604 is definitely the one to get.
This amp is remarkably compact, meaning it will fit in even the smallest spaces, but still delivers a huge amount of power. If you are looking for a reliable 4 channel amp which will deliver great sound for years to come, this should be top of your list.
Contents
- 1 Pioneer GM-D8604
- 2 Alpine MRP-F300
- 3 Boss PH4.600
- 4 Rockford Fosgate R400-4D
- 5 CT Sounds AT-60.4
- 6 Best 4 Channel Amps for the Money
- 7 Our Reviews
- 8 Editor’s Pick: Pioneer GM-D8604
- 9 Alpine MRP-F300
- 10 Boss PH4.600
- 11 Rockford Fosgate R400-4D
- 12 CT Sounds AT-60.4
- 13 Our Final Thoughts on 4 Channel Amps
Editor’s Pick – Top Pick
| Product # | Model |
|---|---|
| 1 | Pioneer GM-D8604 |
| 2 | Alpine MRP-F300 |
| 3 | Boss PH4.600 |
| 4 | Rockford Fosgate R400-4D |
| 5 | CT Sounds AT-60.4 |
| Product | Description | Users Score | |
|---|---|---|---|
Editor choice
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Pioneer GM-D8604Wow. Pioneer have built an enviable reputation over the past few years, and this amp carries on the line of great 4 ... |
User Rating: ( votes)
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Check Amazon
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Alpine MRP-F300This is simply a great 4 channel amp, and represents amazing value. Alpine used to be the choice of serious ... |
User Rating: ( votes)
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Check Amazon
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Boss PH4.600This is a really serious amp. Providing 240 watts of power per channel, it is the most powerful of the amps we ... |
User Rating: ( votes)
|
Check Amazon
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Rockford Fosgate R400-4DRockford are something of a niche brand at the moment, and we admit that we were not familiar with them prior to ... |
User Rating: ( votes)
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Check Amazon
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CT Sounds AT-60.4Last but definitely not least, we have the CT Sounds AT-60.4. This is a great little 4 channel amp, which has quickly ... |
User Rating: ( votes)
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Check Amazon
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Best 4 Channel Amps for the Money
| Model | Size | Weight | Class | Power |
|---|---|---|---|---|
| Pioneer GM-D8604 | 13.3 x 4.9 x 11 inches | 6.5 pounds | FD | 100W x 4 @ 4 ohms |
| Alpine MRV-F300 | 13 x 9.1 x 4.3 inches | 4.6 pounds | D | 50W x 4 @ 4 ohms |
| Boss Audio PH4.600 | 17 x 2.2 x 9.5 inches | 1 pound | A/B | 240W x 4 @ 4 ohms |
| Rockford Fosgate R400-4D | 12 x 9.3 x 4 inches | 5 pounds | D | 75W x 4 @ 4 ohms |
| CT Sounds AT-60.4 | 9.8 x 14.2 x 1.1 inches | 6.7 pounds | A/B | 60W x 4 @ 4 ohms |
What is a 4 Channel Amp?
A good 4 channel amp is the heart of any vehicle’s audio set up. The serious audiophiles we talked to for this review, in fact, said that the best way to design an audio system for your car was to buy an amp first, and then design your speaker system around it.
Vehicle amps come in plenty of different configurations. There are monoblock amps, designed specifically for driving subwoofers, 2 channel, 3 channel, 4 channel, 5 channel, and even 6 channel amps. Which type of amp you choose depends, of course, on what kind of audio set up you are planning on building, but for most purposes we think that a 4 channel amp offers the best compromise between size, cost, power, and adaptability.
As the name suggests, a 4 channel amp has 4 distinct output channels. In the most common configuration, each channel is used to drive a separate speaker. Of course, it is possible to connect as many speakers as you like, by doubling up speakers on each channel, but doing so gets a bit complicated with calculating impedance and the power required for each channel. We would recommend that, for most vehicles, 4 channels and 4 speakers are more than enough for anyone!
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What kind of 4 channel amp you need, and the features you want it to have, depend on how you’re going to use it. An amp for your camper van is quite a different beast to one for your compact!
Some of the things to look for in a 4 channel amp stay the same, though:
- Power. A lot of people talk a lot about power, as though it was a measure of how good an amp is. This is not true. An amp with 50W RMS will easily power most audio set ups, and still go incredibly loud, so always look for sound quality in addition.
- The class of the amplifier. A class A amplifier generally sounds better than a class D, though for most purposes, and especially in vehicle audio, the differences between classes might be so small as to be impossible to hear. In the end, there is no replacement for simply hearing these amplifiers, and choosing the one that sounds best to you.
- Inputs and outputs. It might sound obvious, but make sure the amp you are looking at has the correct type of inputs, and enough of them, to accommodate all the gear you want to plug in! For more about this check out our amp wiring info or read this Wiki article explaining more.
Ultimately, there is no substitute for hearing these amps yourself and that’s why we found the best Youtube videos for each amp. Everybody has different preferences when it comes to how they want their amp to sound. But you could do worse than checking out these ones:
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Editor’s Pick: Pioneer GM-D8604
Wow. Pioneer have built an enviable reputation over the past few years, and this amp carries on the line of great 4 channel amps.
In addition to great sound and all the features you would expect from a modern 4 channel amp, what really makes this amp stand out is its size. It is tiny in comparison to many of its competitors like many small guitar amps. . This may seem like a strange feature to mention, given that once installed the amp will just sit in your vehicle, but the compact design of this amp makes it really versatile.
Even if you have quite a small vehicle, this amp will easily fit. And in larger vehicles, it is nice to know that your trunk space will not be taken up with a huge amplifier, because you can easily attach this one in an out of the way spot!
Not that this compact size means Pioneer have compromised on power. With 4 channels of 100 watts at 4 ohms, this tiny amplifier has an enormous amount of power. In honesty, even if your vehicle is large, and you are planning on installing 8 speakers, this amp has all the power you will ever need.
In addition to great sound and all the features you would expect from a modern 4 channel amp, what really makes this amp stand out is its size. It is tiny in comparison to many of its competitors. This may seem like a strange feature to mention, given that once installed the amp will just sit in your vehicle, but the compact design of this amp makes it really versatile.
In addition, of course, this Pioneer amp comes with a variety of other advantages:
- The serious audiophiles we spoke to for this review praised this amp as the best way to start a serious car audio system. It is not the cheapest available, but what you get for your money is quite incredible – the power offered by this amp means that even if you decide to upgrade your speakers, or add a subwoofer, at a later date, you will not have to change your amp!
- The amp has some great and innovative safety features. Pioneer have included a system which automatically senses the amp’s temperature, and then modulates the input level accordingly. This ensures that you don’t have to worry about frying your amp, even when pushing the volume to the maximum!
- Sometimes, high-powered amps like this can be really inefficient. Not here – the class FD amplification used in this amp is incredibly efficient, meaning that even when pumping out loads of power the amp is not a huge drain on your electrical system.
- Last but not least, the amp sounds great. We are not sure how Pioneer have managed to achieve such great quality sound in a class FD amplifier, but this amp really gives class A amps a run for their money. Even when pushed to maximum output, there is no clipping. Your speakers will give up before this amp even breaks a sweat.
- In truth, none. If you are looking for a powerful amp that is small enough to fit in even the tiniest vehicle, this is the one to get. Highly recommended for those who are starting a serious vehicle audio set up!
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Alpine MRP-F300
This is simply a great 4 channel amp, and represents amazing value.
Alpine used to be the choice of serious audio enthusiasts, having been founded in 1967, and have made everything from speakers to amps to head units in that time. This amp is therefore the culmination of many years specialization in car audio, and the sound quality certainly confirms this!
Whilst not the most powerful amp we tested, the power produced by this amp should be more than sufficient for most requirements. It provides enough power to drive even the most power-hungry speakers, and will still go incredibly loud, so don’t worry that you won’t be heard.
In addition, this amp is nicely compact, meaning that installing it in even the smallest vehicle is a breeze. Even in larger vehicles, the easy mounting will mean that it can be neatly mounted, either tucked away out of sight or on display for all to see!
Alpine used to be the choice of serious audio enthusiasts, having been founded in 1967, and have made everything from speakers to amps to head units in that time. This amp is therefore the culmination of many years specialization in car audio, and the sound quality certainly confirms this!
In addition, this amp has these great features:
- It looks great. Whilst we know that the majority of audiophiles claim to care only about sound quality, and not such unimportant things as the way an amp looks, in reality it is possible to have both a good-looking and high-quality amp – just look at this one!
- The thermal protection system on this amp is super good. Alpine have put all their years of experience into ensuring that this amp will keep itself cool, even when pushed to the limit. Whilst most people will never need to push this amp to the limit, it is nice to know that you can do so without frying it!
- The compact size means that this amp can be hidden away really easily – it can be mounted in any small space you have in your vehicle, though it looks so good that we would recommend putting it somewhere your friends can see it!
- The adaptability of the amp is great. It will drive a vast variety of different set ups, and can be bridged to power a sub woofer, meaning that if you are on the lookout for a new amp to power your already-existing system, this could be a good bet.
- None, for the price. This amp offers the sound quality and power of many larger and more expensive amps, and is an excellent investment.
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Boss PH4.600
This is a really serious amp. Providing 240 watts of power per channel, it is the most powerful of the
amps we tested, and can be used to drive even the largest speaker set ups. If you are looking for serious power and volume, this is the 4 channel amp to get.
It is so powerful, in fact, that most people will never be in a position to push the volume it will produce. All that power gives it great advantages even at low volumes though, providing better control of the speaker cones and sound produced.
It is also a class A/B amplifier, which provides great sound quality. Whilst this also makes it one of the largest amps we tested for this review, if you are spending this kind of money on an amp you kind of want a big, impressive block of an amplifier to show off with! Mount it front and center in your trunk, and invite people to have a look.
It is so powerful, in fact, that most people will never be in a position to push the volume it will produce. All that power gives it great advantages even at low volumes though, providing better control of the speaker cones and sound produced.
In addition, this amp comes with some great features:
- The bass on this amp is quite simply amazing. Even at the loudest volumes, the bass response stays clear and warm, meaning that you can really push this amp and still be assured that your audio will not clip or distort.
- The high- and low-pass filters on this amp give it added adaptability. You can easily mess around with the audio settings on this amp in order to perfectly tailor its output to your system, and get the best sound quality.
- You can also ask it to give you up to 18 db of bass boost, and doing so really makes this amp come alive. At maximum bass boost, it produces a serious bass sound which will be heard throughout the neighborhood.
- The build quality of this 4 channel amp is second to none. Boss have been building this kind of amp for many years now, and their experience is on display here. All the connections are gold plated, offering not only the best quality sound but also ensuring that the amplifier will give many years of reliable service.
- Very few. Some of the people we talked to for this review said that when being used to the limit, the thermal protection on this amp kicked in quite a lot, compromising on the sound quality. We did not encounter this problem, however, and suspect that as long as the amp is mounted somewhere that is well-ventilated, this will not be a problem for you.
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Rockford Fosgate R400-4D
Rockford are something of a niche brand at the moment, and we admit that we were not familiar with 
them prior to writing this review. However, on the recommendation of some serious audiophiles, we looked at this amp, and we are glad that we did.
What really stands out here is the sound quality. For most people, especially in car audio, the differences between the frequency response of amplifiers is so slight to be unnoticeable, but as soon as we plugged this one in we realized that this amp is one of the best available.
The output of this 4 channel amp stays incredibly clean, even when driving low quality speakers, and even when pushed to near its maximum volume. If you listen to electronica, in particular, this has great advantages, as all those gorgeous synthesizer tones stay well defined. The sound quality is on par with any tube amp.
If you are looking for great sound quality, and don’t mind paying a little extra for it, then this is the amp to get!
What really stands out here is the sound quality. For most people, especially in car audio, the differences between the frequency response of amplifiers is so slight to be unnoticeable, but as soon as we plugged this one in we realized that this amp is one of the best available.
In addition, this amp has several big advantages:
- It delivers more than enough power for most situations. With 75 watts of power, you will not have to worry about being heard anywhere. When paired with suitable speakers, the volume output of this amp rivals those with 100 watts or more of power.
- The build quality of this amp is something else. From the moment you receive this amp, you will be impressed with how solid it feels, and we are confident that it will put up with years of abuse without complaining.
- The amp is fully bridgeable, making it a great investment. You can connect the back 2 channels together, and power your sub with up to 200 watts RMS, or even use it as a dedicated subwoofer amp, powering 2 subs together!
- The protection on this amp is as good as you would expect from the price. It offers 3 stages of protection – thermal, over-current, and short-circuits, meaning that even if your vehicle suddenly develops an electrical fault, you can be sure that your amp will be safe.
- Very few. This is one of the more expensive units we reviewed, but we also think it is on of the best. For just a little more than the other amps listed here, you get sound quality which is undoubtedly better than any other amp on the market today.
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CT Sounds AT-60.4
Last but definitely not least, we have the CT Sounds AT-60.4. This is a great little 4 channel amp, which 
has quickly made a reputation as a solid performer, able to put up with the worst abuse and keep going.
It is a class A/B amplifier, and delivers all the sound quality you would expect from such an amp. Whilst class D amplifiers are quickly making inroads into the 4 channel amp market, to our mind nothing beats the clean sounds of a class A/B – there is a warmth to the tone that it is just not possible to get with a more “electronic” amp.
This is a well-rounded design. The body of the amplifier is compact, but also looks great, meaning you can either mount it somewhere out of the way, or put it in a place where it is easy for your friends to admire its clean lines.
It is a class A/B amplifier, and delivers all the sound quality you would expect from such an amp. Whilst class D amplifiers are quickly making inroads into the 4 channel amp market, to our mind nothing beats the clean sounds of a class A/B – there is a warmth to the tone that it is just not possible to get with a more “electronic” amp.
Of course, this amp also has several more advantages:
- It delivers more than enough power for most set ups. With 60 watts per channel, it is not the most powerful of the amps we are reviewing today, but in honesty not many people will notice. When paired with the correct speakers and set up correctly, this small amp produces more than enough volume for anyone.
- The amp is fully bridgeable, giving it a high degree of adaptability. Bridge the back two channels, for instance, and you will have more than enough power for your sub in addition to your front speakers.
- The bass knob on this amp is a great feature, allowing you to quickly adjust the amp’s output to your desired sound. This means that no matter what kind of music you listen to, you can always find the perfect sound!
- The build quality here is outstanding. The people we spoke to for this review praised the fact that this amp felt really sturdy, which is a must in an amp that will be mounted in your trunk. You can throw the rest of your gear in the trunk, and be assured that your amp will not break. This is a great beginner amp as well.
- Very few. If you are looking for a compact 4 channel amp that sounds great, you could do worse than considering this one!
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Our Final Thoughts on 4 Channel Amps
So which to choose?
Well, your choice of 4 channel amp is yours alone, of course. Nothing can beat hearing these amps for yourself, and finding one that perfectly matches the sound you want to achieve. All of the amps we reviewed today offer incredible sound that we are confident will please even the most discerning audiophile.
When buying a 4 channel amp, of course, you also need to consider the set up you are trying to achieve. If you are fitting out a camper van, and want 8 speakers, go for one with plenty of power. If you want the best sound quality in your car, this is not so important, as any of the amps we have reviewed are more than loud enough for your purposes!
Our overall choice, though, is the Pioneer GM-D8604. This amp is remarkably compact, meaning it will fit in even the smallest spaces, but still delivers a huge amount of power. If you are looking for a reliable 4 channel amp which will deliver great sound for years to come, this should be top of your list.
