Is your current car stereo not producing a high enough sound quality and volume for you? Do you have front and rear speakers too? Then the answer to your problems could be in finding the right 4-channel amplifier for your needs. The best 4-channel car amplifiers are the surest way to get premium sound from the front and back speaker combinations. Even if you have just two speakers and a subwoofer a 4-channel amplifier will still work well for you.
In this article, we will do several 4-channel car amplifier reviews. That way you will get the heads up on what might be a good 4-channel amplifier for you. At the very least it will give you a good idea of what you need to look for in a 4-channel amplifier when you are out shopping for one. Once you purchase and install your new 4-channel amp you will not believe how much better your car stereo sound quality will be.
Best 4-Channel Car Amplifiers Comparison Chart
| PRODUCT | DETAILS | ||
|---|---|---|---|
 | Rockford Fosgate P600X4 Punch Amplifier |
| View On Amazon |
 | MTX Audio THUNDER75.4 Thunder Series Car Amplifier |
| View On Amazon |
 | Kenwood 22154656 Compact Digital Amplifier |
| View On Amazon |
 | Alpine MRV-F300 Car Amplifier |
| View On Amazon |
 | Pioneer GM-D8604 Bridgeable Amplifier |
| View On Amazon |
 | Skar Audio RP-75.4AB |
| View On Amazon |
Best 4-Channel Car Amplifier Reviews (Updated List)
1. Rockford Fosgate P600X4 Punch Amplifier
Rockford Fosgate amplifiers are some of the best-selling car amps you will find. That’s because this company has a reputation for building quality amplifiers that help create superior sound in any car stereo system. This fine amplifier from them will put out 125 watts per channel at 2-ohms of resistance.
The included Auto turn-on circuit makes wiring this amplifier easy too. Once it senses the voltage going through the system this 4-channel Rockford Fosgate amplifier will fire itself up without you having to manually turn it on.
It’s an amplifier that stays fairly cool too thanks to its built-in aluminum heat sink. Other safety features on it include both overload and short-circuit protection.
Due to its built-in RCA pass-thru outputs, you can very easily hook up a rear subwoofer to the Rockford Fosgate P600X4 amp too. That will give you all the power you need to blast your car music with lots of heavy bass.
Pros:
- Auto turn-on circuit
- 129 Watts x 4 @ 4-Ohms 0° Res
- Perfect for 4-way or 3-way subwoofer systems
- Cast aluminum heatsink
- Short circuit and overpower protected
- RCA pass-thru outputs
Cons:
- Not great for feeding multiple subwoofers
- Heavy at 12.8 pounds
2. MTX Audio THUNDER75.4 Thunder Series Car Amplifier
MTX is a leader in car and marine audio for a reason. They put a lot of effort into the design of their products that helps them become big part of a great car or marine audio experience. This amplifier from them will produce up to 400 watts of dynamic sound in your car stereo system’s speakers.
Not only is this 4-channel car stereo amplifier powerful but it is a lightweight and compact amplifier too. It’s built to be easily surface mounted in even smaller spaces in your vehicle. The surface mount design it has also helped it handle vibration and is ideal for easy hookups too.
It stays cool when running thanks to its extruded aluminum heatsink and it also features very good triple circuit protection.
Its 2-ohm stability comes in very handy too. That makes it a very flexible amplifier that can be used in many different car stereo systems.
Pros:
- Small footprint for a powerful 4-channel amp
- 400 Watts total power output
- Surface mount design
- Extruded aluminum heatsink
- 2-ohm stability
- 4-Channel Class A/B Amplifier
Cons:
- The panel layout is congested due to its small size
- Interferes with FM radio frequencies
3. Kenwood 22154656 Compact Digital Amplifier
You don’t get a more trusted name in car stereo equipment than Kenwood and this is a very good 4-channel amplifier from them. This surface mount amplifier from them is simple to install and comes with easy access hookups too. Its peak 600-watt power output should satisfy almost any car stereo owner with three or four-speaker stereo combinations.
It has such unique amplifier features as true RMS power and it has a voltage sensing auto-on switch built into it also. We were pleasantly surprised how powerful this amplifier is for its small size.
If you have a vehicle with very little space to locate an amplifier this one will probably be an excellent choice. It measures only 3” x 7” x 6” and weighs only a scant 2.2 lbs.
This amplifier is fully circuit protected and its printed circuit board is nicely coated to help it shed moisture and resist corrosion.
Pros:
- Easy to place the compact size
- 600 Watts peak power output
- Surface mount design
- Coated printed circuit board
- Signal sensing auto turn-on feature
- True RMS power
Cons:
- Short 1-year warranty
- No built-in 4 channel to 2 bridging
4. Alpine MRV-F300 Car Amplifier
You would expect the reputable stereo equipment manufacturer Alpine to have a 4-channel amplifier that makes our countdown of the best models and this is a good one from. It’s been newly redesigned to be smaller and more lightweight without sacrificing power.
This amplifier can generate up to 640 watts of total power. In a standard 4-channel configuration, it can consistently deliver 75 watts of power to each speaker too. It runs extremely cool even after being used for a long period of time. Alpine claims it’s because of the anti-shutdown technology they build into this amplifying unit. We certainly are convinced there is something special about its ability to keep cool.
Do you want a 4-channel amplifier that’s easy to install? Well, they don’t get much easier to install than this one. It’s a surface mounted amplifier in a compact package. You don’t need to go to the trouble of hooking it up to any external converters either and its terminal covers use easy snap-on connections too.
Pros:
- Anti-shutdown design
- 75W RMS x 4 (2Ω)
- Class D digital amplifier
- Snap-on terminal covers
- 40% smaller than the previous model
- No external converters needed
Cons:
- No RCA outputs
- A slight amount of noise in the system
5. Pioneer GM-D8604 Bridgeable Amplifier
Pioneer is known for making excellent car stereo components that are affordable and that is pretty much spot on what you get with this amplifier from that. It will help you pump some big sound out of your front and rear car stereo speakers without breaking the bank.
It won’t be hard to find a space for this compact car stereo amplifier the way it’s designed. Not only that, but it will deliver 100 watts per channel of power at 4-ohms of resistance. The Pioneer GM-D8604 has a new circuit design that will protect it from power surges, low voltage outputs, and short circuits too.
Want to pair your front auto speakers with a subwoofer in the back. That’s not a problem with the Pioneer GM-D8604. It’s completely bridgeable so you can combine the two dedicated lines going to the back to adequately power most car subwoofers. That makes the Pioneer GM-D8604 a very versatile amplifier.
Pros:
- Compact but mighty
- 100 Watts per channel power x 4 @ 4-ohms
- Class D digital amplifier
- Improved circuit design
- Completely bridgeable
- Comes with adjustable bass remote
Cons:
- Can run a little hot at times
- Only comes with a short 1-year warranty
6. Skar Audio RP-75.4AB
Skar has developed a trust relationship with customers when it comes to the know-how on sound systems and amplifying. The RP-75.4AB adds more truth to that statement with its high-quality material and features.
With the 4 Channels and a full-range using high and low pass filters, you can efficiently run even more than eight speakers on the Skar RP-75.4AB. As long as you pay attention to the ohm load and adequately set gains with a multimeter before playing, you are safe.
Bridging is possible, and a fuse of size 50-A will be a good option for this amplifier. Connecting the amplifier straight to speaker wires is not an option because only RCA inputs are on it, but you can just buy jacks and set up. The recommended cable size is 4 gauges.
As an addition to the customization possibilities, the amplifier allows you to connect to it by Bluetooth, and you can also use it on tweeters. The signal to noise ratio is of 105db, and the frequency response has a high range from 20Hz to 20 000Hz.
Pros:
- A and B Class/Full-Range
- Bridging is possible
- 4 Channels for multiple speaker connection
- Bluetooth connectivity
- Tweets can also be added
Cons:
- A Bass knob is not available
| PRODUCT | DETAILS | ||
|---|---|---|---|
 | Alpine KTP-445U Power Pack Amplifier |
| View On Amazon |
 | Skar Audio SKv2-100.4AB Car Speaker Amplifier |
| View On Amazon |
 | Kenwood 1177524 Compact Amplifier |
| View On Amazon |
 | Rockford Fosgate Power T400-4 Multi-Channel Amplifier |
| View On Amazon |
 | Soundstream PN4.1000D 1000W 4-Channel Picasso Nano Series Amplifier |
| View On Amazon |
 | Kenwood KAC-M3004 Compact 4-Channel Digital Amplifier |
| View On Amazon |
7. Alpine KTP-445U Power Pack Amplifier
Alpine usually delivers when they make a car stereo product and this very nice car stereo amplifier from them is a testament to that. It’s a super-compact model car audio amplifier that surprises you with big sound it will help you get from your front and back car speaker setup.
Do you have space limitations in your vehicle and think it will be hard to install an amplifier on your stereo system? Guess again. This amplifier takes up only 8″ x 2″ x 3” of space. That means it can even be mounted under a seat if necessary.
It puts out a very adequate 45 watts of power per channel (x4 @ 4Ω) and it can be configured to filter out a wide variety of frequencies too. For its class it has one the best signal to noise ratios you will find. It also includes the wiring harness with both RCA and auto-sensing speaker connections.
Pros:
- Super-Compact class D amplifier
- 45 Watts per channel power x 4 @ 4-ohms
- Versatile frequency filtering
- RCA & auto-sensing speaker-level connections
- High output/Dynamic response
- Great signal to noise ratio
Cons:
- No low pass crossover
- Included instructions need improvement
8. Skar Audio SKv2-100.4AB Car Speaker Amplifier
The Skar amplifier leaves its mark on sound quality with its 800W of maximum power and 105db sensitivity. Yes, it comes at a higher price, but you get your money’s worth. Made of high-quality components, this car speaker amplifier produces a better sound with less distortion.
Alongside all the adjustment tunings, the safety feature of the heatsink design, Skar, gives you even more with the RCA outputs. You can strap your amplifier, just as long as you set one of the amplifiers a controlling one.
The 10.4AB amplifier can handle up to four sets of midrange speakers with a subwoofer power level of up to 900W. The Korean produced Skv2 lines are highly recommended amongst all the other types. You can use both ten-gauge or eight-gauge speaker wire, and it comes with a bass knob.
It is possible to wire the amplifier to two subwoofers just as long as you run the to 1ohm.
Pros:
- Highly adaptable allows for connecting multiple speakers, strapping, etc.
- High signal to noise ratio
- Made with quality components
- Very powerful
Cons:
- Damages sometimes occur during logistics
9. Kenwood 1177524 Compact Amplifier
Here is the first 4-chanel stereo amplifier in our countdown of the best ones that you can actually use with a Bluetooth application. With as many people that use apps to play their music on it makes sense that someone would design a Bluetooth compatible amp and Kenwood has done that with this model.
It has some very decent sound power for its smallish size too. It puts out a very respectable 45 Watts per channel power when hooked up to 4 speakers (4-ohms). It has a coated PC board that helps make it moisture resistant and it has a signal sensing turn-on switch too.
This compact amplifier is not only limited to being installed in vehicles either. It will work very nicely in boats, RV’s, and on ATV’s and motorcycles too. It not only does not take up a lot of space but it doesn’t pull much DC current to run either.
Pros:
- Bluetooth compatible
- 45 Watts per channel power x 4 @ 4-ohms
- Moisture resistant PC board
- Includes waterproof remote control
- Works well on boats, RV’s, ATV’s and Motorcycles
- Signal sensing turn-on
Cons:
- Included blue background light can be bothersome if seen when driving at night
- Volume controls do not work when hooked up in the line-in mode
10. Rockford Fosgate Power T400-4 Multi-Channel Amplifier
Another premium product from Rockford and this time it is less powerful but very capable amp which has crystal clear sound and lots of features. This 4 channel amplifier delivers 60W x 4 at 4-Ohms, 100W x 4 at 2-Ohms, 200W x 2 at 4-Ohms bridged (RMS) so it is modular and compatible.
It is a class A/B amplifier with variable front/rear high-pass/low-pass filters with a range of 50-500 Hz which makes a very clear sound and reduces the background noises. It is more affordable than some other Rockford Fosgate products so it will appeal to a wider audience so if you want one of the best products on the market, you should check this amp for sure.
11. Soundstream PN4.1000D 1000W 4-Channel Picasso Nano Series Amplifier
The cost to quality ratio on the Soundstream PN4 is absolutely in favor of quality. Finding a product at a moderately lower price but with good quality is usually very difficult. Look no more, though. Using Korean produced components and adding the necessary safety features gets the job done.
The maximum power output is 500 watts, and the RMS power rating at 4ohm is 140 watts. Safety solutions are looked after with thermal overload and short speaker protection.
This 4-channel amplifier comes with a high-level speaker input harness and RCA inputs. The speaker wire connection is of screw type, and you will need an external fuse of 60 amps rating. Bridging is possible with a 4-ohm load only.
Pros:
- Very compact, which makes it suitable for diverse use. On motorcycles, boats, and others.
- Clean sound and high volume
- Low cost but good quality and performance
Cons:
- Defects on units have occurred
12. Kenwood KAC-M3004 Compact 4-Channel Digital Amplifier
With 50 watts RMS per channel, the Kenwood compact amplifier gets you through your journey, overcoming the surrounding noises with ease. You can fit it almost anywhere on in your car, motorcycle, or boat.
Installing subwoofers, bridging, and adding speakers is not a problem. Any signal source is suitable; whether from the RCA input or speaker wires, it will sensibly turn itself on and bring the beat.
The input sensitivity varies from 0.2v to 5v. Depending on the volume you use, the unit draws increasing or decreasing amps. As long as the battery is charging while the engine is running, you will always have enough power.
The Kenwood KAC-M3004 will function and work properly in the outdoors but is not waterproof, so ensure it is kept away from water to prevent any damage to the interior components. It is easily mounted using high-grade Velcro. Therefore you don’t need mounting brackets.
The amplifier comes with a harness for the speaker input, and both HP and LP sound switches are available.
Pros:
- Compact size for a comfortable fit
- Very powerful for its size
- Bridging is possible
Cons:
- Overheating may occur at times
13. BOSS AUDIO PF1800 Phantom 4 Channel Amplifier
Very affordable and very versatile product from Boss Audio in form of PF1800 Phantom amp. It has a pretty decent power output of 1800 W and working range from 2 to 8 ohms which are good to know and usable.
It also features full-range, MOSFET power supply, high and low level inputs, variable high pass crossover, variable low-pass crossover, variable bass boost and remote subwoofer control, Impressive specifications and options in sub 100$ package is obviously intended for budget users that need a lot of stuff and power but don’t have a lot of money.
Users reported that this package delivers on its promise and is a good proposition for any in-car enthusiast on the budget.
Advantages Of 4 Channel Amplifiers
The 4 channel amp is a reasonable proposition for moderate car audio fan which gives him enough options. You can use 4 channel amp only and connect it to four speakers or you can bridge it to have a subwoofer or you can have another amp over it for full power and multi-device connection. It is up to you.
On the other hand, 4 channel amps are compact and cheaper than 5 channel amplifiers and more in reach of a regular in-car audio fan. You can find really small ones which can fit anywhere and you can find even 4 channel amps that are built for special use – like in boats and floating objects.
Some Final Thoughts on the Top 4-Channel Amplifiers
This certainly is a fine collection of 4-channel amplifiers that we have on our review list here. They are most certainly among best 4-channel car amplifiers you will find in the car stereo marketplace. Many of them are versatile and that you can adjust such things as the frequency and bass on individual units too. That gives you a lot of flexibility as to how you like your amplified music to sound.
There is no reason that anyone who is looking for a new 4-channel amplifier should not find one of the products to their liking that we did the 4-Channel Car Amplifier reviews on. At the very least you can use our reviews as a guideline of what to look for in a 4-channel amp for your vehicle.