If you’re building your own audio system for a car, one of the main components you’ll need is an amplifier.
Four-channel amplifiers are favored by most people creating a custom stereo system because they can power four speakers or two speakers and a subwoofer.
Given how common this setup is in vehicle sound systems, we decided it would help our shoppers to put together reviews of the top 4 channel amps on the market today.
Top 4-Channel Amps for Sound Quality
1. Rockford Fosgate R300X4 – Best All-Around
2. Alpine MRV-F300 – Best For Door Speakers
3. Rockville dB45 – Best For The Money
4. Kenwood KAC-M3004 – Best Budget Amplifier
5. Pioneer GM-D8604 – Best For Mids And Highs
- Top 4-Channel Amps for Sound Quality
- How to Select the Right Four-Channel Amp
- The Bottom Line
Below is a list of the best 4 channel amps for sound quality for powering an entire car audio system.
1. Rockford Fosgate R300X4 – Best All-Around Car Amplifier
It comes with features like current and temperature sensors to protect it from damage, and the aluminum chassis efficiently dissipates heat.
The speaker-level inputs make it possible to connect it to most stereo models that you might have in your car.
We recommend this audio system amp for any standard speaker setup, whether you have a set of four speakers or want to add a subwoofer to a pair of speakers.
2. Alpine MRV-F300 – Best 4 Channel Amp For Door Speakers
It weighs in at only 4.5 lbs and measures just 13 x 9 x 4 inches.
If you already have a primary amp and want to install a second one, the MRV-F300 is a good candidate.
This mid-range amp has plenty of power for normal music and radio volume or to boost two channels as a secondary amp.
It’s rated at 75W x 4 channels RMS or 150W x 2 channels RMS. It’s also equipped with circuit protection like a MOSFET power supply and safeguards against overloads, shorts, and overheating.
3. Rockville dB45 – Best 4 Channel Car Amp For The Money
The IC-controlled circuit includes a peak-limiter that eliminates distortion in the audio when you crank it up.
The maximum wattage reaches 3200W and 1600W RMS. With that kind of power output, it also comes with undervoltage and overvoltage protection at 10 and 16 volts respectively.
4. Kenwood KAC-M3004 – Best Budget Compact Digital Amplifier
That’s thanks to a fully digital audio processor that delivers a peak power rating of 600W.
It can be set up for 50W x 4 channels, 75W x 4 channels, or 150W x 2 channels.
With its compact size, it’s ideal for audio systems in cars, boats, and ATVs. That also means it’s designed to survive the elements with conformal coating on its main board to prevent corrosion.
We recommend this amp for the value you get from its durability, digital clarity, and respectable power profile.
5. Pioneer GM-D8604 – Best 4 Channel Amp For Mids And Highs
Pioneer’s GM-D8604 is the best compromise we could find that combines these two features. It’s a Class D amp ready to squeeze into a tight space behind your dash or mount next to a primary amp.
The peak power on this amp is 1200W, with four-channel setups ranging from 100W to 150W RMS. You can also bridge it to power a subwoofer with 300W RMS. The signal is kept clean with high- and low-pass filters and a frequency range of 10-50 kHz.
We definitely recommend this amp if you want more than the standard power and good sound quality.
How to Select the Right Four-Channel Amp
Four-channel amps are not all the same beyond the fact that they provide four channels of audio signal. What other factors should you consider when comparing them? That depends on the type of speakers and stereo you have and the quality of sound you want. Below are the major specs that you should check as you narrow your choices down to the right amplifier.
The wattage of an amplifier is a measure of how much power it can deliver to your speakers, which translates into volume when converted to sound. The primary function of an amplifier is to multiply the wattage of the original audio signal to the speakers. For most audio systems, wattage ratings between 50W and 75W RMS will provide plenty of power. Be sure to check that your speakers are rated for the amp’s wattage before you buy it.
Resistance is an electrical spec measured in ohms. It matters because you’ll want to choose an amp and speakers that match each other’s resistance to ensure they work well together. In particular, you’ll want to avoid matching speakers with a resistance that’s lower than an amplifier’s minimum.
Of course, you need to have a place somewhere in your vehicle to mount your amplifier, so its physical shape and size can be a deciding factor as you compare options. A larger vehicle like an SUV will have more free space for an amplifier than a compact car, so find the place you want to put your amp and measure the dimensions carefully. Check candidate amplifiers against those measurements before you place an order.
There are a couple of different classes of amplifiers you’ll see designed for car audio systems. Class A/B amps have less efficiency than Class D amps, but their noise levels are lower. On the other hand, Class D amplifiers are more compact, which makes them ideal for fitting them into cramped spaces behind a car dash.
Other Extras to Look For
Amplifier technology is fairly standard today, but not all amps come with the extra features you’ll find with premium products. Sound quality is affected by the noise level and filters included in an amp’s design. You may want to get an amp with crossovers, especially if they are adjustable. The materials and design of the terminals are important, too, for good sound and longevity once the wiring is done.
In this year’s guide to the top five 4-channel amplifiers, we’ve tried to give a cross-section of the most common alternatives that support different car audio needs. If you’re looking for raw power, Rockville's dB45 and Pioneer's GM-D8604 were the two options we liked best. Those in need of crystal clear audio will be impressed by Kenwood's KAC-M3004. Watch for future reviews of the best car audio amplifiers as more become available!