The Best Car Amplifier
Most of the time, when people think about upgrading their car’s sound system, it’s all about the speakers themselves—but the best car amplifier on the market can truly take your sound to the next level. Whether you want thumping bass, all around clear audio, or a little bit of both, you need the best car amplifier to really make your speakers shine.
In addition, there are many different types of car amplifiers out there, all for different purposes. Because sound amplification is so technical, many people shy away from really diving into the possibilities inherent in having the best car amplifier. This guide can give you the knowledge you need to get comfortable looking at amps and deciding which one is the best for you.
While I’ll go into detail regarding each of the top five car amplifiers I’ve chosen for review in just a minute, this table will help you make an informed decision and better understand the way the amps stack up against each other.
Don’t worry if you don’t understand all these specs just yet—this article is for those new to car audio as well as the more experienced.
After the reviews, I’ll give explanations for the most important specs and stats when it comes to the best car amplifiers, so you can make an informed decision.
Rockford Fosgate is one of the most respected names in the car audio business, especially when it comes to amplification.
When I opened the package for the R500X1D, I was impressed: it’s a great looking and clearly well-made car amplifier.
I particularly like the placement of the control knobs on the top instead of the side—it makes fine-tuning a breeze whenever I want to tweak my sound.
I installed this in my Subaru Outback and used it to power two Kicker 200 watt subwoofers.
This amplifier impressed me with its sound quality. The power it supplied to my speakers was clearly consistent, and I never had issues with clipping. The amplifier’s construction is also solid, and all in all it just looks nice.
Durable as Well as Powerful
The best feature, though, might be its heat sink. Amps produce a lot of heat, so any kind of onboard system for keeping the amplifier from overheating is a plus in my book—and this amp never seemed to run too hot, even when I specifically ran it on hot days to check its endurance.
No amp is invincible to heat, but this one is especially durable.
A Few Small Problems
There are a few things I didn’t like about this amp, though none of them are dealbreakers.
The angle of the wiring screws is a bit odd—instead of being flat, they’re at about a 45 degree angle, which might make adjusting them in a tighter space difficult.
Overall, I’d definitely recommend this amp to anyone looking for clean, consistent power to their subwoofers.
The sound quality is great, and this amp can definitely pump up the volume. If you need lower or higher wattage, there are other amplifiers in this series (Punch) that will suit your needs.
Higher Price, but Great Value
Though this amp is a little too pricey to be considered a budget choice, it’s not overly expensive and it packs a lot of value into every dollar of the price.
- 300 Watts x 1 @ 4-Ohms, 500 Watts x 1 @ 2-Ohms, Frequency 20Hz to 250Hz +/-1dB
- Onboard 12dB/octave LP/HP/AP crossover & Infrasonic filter. Power Wire Gauge- 4 AWG. Power Input Connector-Screw Terminal. Suggested Alternator-75 A
- On-board Punch EQ with +18dB boost at 45Hz. Input Sensitivity: 150 mV to 4 V
- Cast Aluminum Heatsink with Stealth top mounted control panel
- Includes wired remote (Punch Level Control). High efficiency amplifier design that reduces current consumption from the charging system
Pioneer is another one of those brands that’s a classic. For quite some time, Pioneer has been respected in both home and car audio.
I actually use a Pioneer head unit in my everyday driving vehicle, and own a Pioneer home stereo system.
Needless to say, I was excited to try this amplifier out.
When I unboxed the GM-D9605, I was surprised at how small it is. 5-channel amps are usually monsters, but this one fit all its hardware into a fairly compact casing.
This made me worry about overheating a bit, but I was impressed at the implications this has for getting all around great sound in small spaces, like sports cars and truck cabs.
Control, Ease of Use, and Great Audio Quality:
The design seems geared toward user-friendliness and ease of use, but also allows you plenty of flexibility to change up your sound. I was impressed with its design and the high quality of manufacture.
The amp stayed cool as I ran it, and the casing looked nice and seemed very sturdy.
The Devil is In the Details
If you buy this one, I’d recommend throwing in some new screws—just be sure they’re the right size.
All in all, I’d recommend this amplifier to anyone looking to upgrade their whole sound system.
Lots of times, 5-channel amps seem either much more focused on the door speakers or on the subs, but this one put plenty of power into both. In addition, it’s very well-made and surprisingly compact.
A Word of Warning
I only mention this because I have a good friend who lost a couple hundred bucks getting a Pioneer product from an unauthorized dealer. Even if the price is a tad higher, it’s worth every penny.
Kenwood’s amplifiers and speakers are well-known throughout the car audio world, and they were one of the biggest pioneers in the industry when subwoofers really started taking off back in the 1980s.
The 22154656 seeks to be a continuation of their legacy of high quality products.
Convenience in a Compact Package
However, its main design feature is its compact size. This amp can fit virtually anywhere, so it’s perfect for truck cabs and compact vehicles.
I even have a friend who’s hooked this up on his motorcycle!
Hot, Hot, Hot!
I will warn potential buyers of this product that its extremely compact size makes it a bit more prone to overheating. This isn’t to say that this amp is badly made or that you shouldn’t buy it.
In addition to its small size, this amp blew me away with its versatility. I tested it in two ways: once as a door speaker only amp and once powering both the door speakers and a subwoofer (on its 3-channel setting).
It impressed me with both setups. This little amp means business, and provides plenty of power at 75 watts per channel.
I also tested it with both stock door speakers and higher end aftermarket ones. It puts in enough work to really make nice aftermarket speakers shine, but it also provides a really nice boost to stock speakers.
Obviously better speakers sound better, but if you’re on a budget and upgrading one part of your system at a time, this amp can make even stock speakers sound really solid and punchy.
What This Amp is For
Planet Audio is a somewhat newer brand in the car audio scene, so the AC2400.4, part of the manufacturer’s Anarchy series, works really hard to prove itself.
At 2400 watts peak and stable at 2 ohms, this amp provides some serious blast—and at a fairly low price point, it provides a lot of value.
If you purchase this amp for your vehicle, I’d definitely recommend replacing the screws before or during installation.
In addition, the size of this amp might be a bit of an issue for some users. In truth, you can’t get much smaller of an amp with this much power, but the size can make it difficult to install.
Be sure you know where you’re going to put this thing before you buy.
After replacing the screws and finding a good place to install it, though, this amp blew me away. It is simply amazingly powerful.
Be sure that you pair this with high-quality, high wattage speakers—whether they’re subwoofers or door speakers—because without great speakers, you won’t be getting the full experience of this amplifier.
Clear and Consistent High-Powered Sound
I was amazed at how clear the sound from door speakers is when powered by this amp, even at high volumes. This amplifier provides crisp and consistent power, and doesn’t suffer from clipping or similar issues.
In addition, it packs more than enough power to give you some thumping bass in the mix with the clear highs and mids.
Paired with great door speakers and subwoofers, it can truly take your sound to the next level.
- 600 W MAX Power @ 2 Ohm x 4 Channels
- 300 W MAX Power @ 4 Ohm x 4 Channels
- 1200 W MAX Bridged Power @ 4 Ohm x 2 Channels
- Full-Range, Class A / B Topology, MOSFET Power Supply
- Low and High Level Inputs, Variable Filter, Variable Bass Boost
- Remote Subwoofer Control, Blue Backlit Illumination
- Dimensions: Depth 17" x Width 10" x Height 2.4"
- 6 Year Platinum Online Dealer Warranty
More Power than You’d Expect
If you want a small, simple package that makes your subs thump, the R1100M Riot might just be the amplifier for you.
Upon installing this amplifier, I was immediately impressed with how well it pushed my two Kicker 200 watt speakers, and because this amp produces an RMS of 825 watts, I could continue using it even if I upgraded my subwoofer setup.
Something to Look Out For
Try it at a low volume first, and increase until you find your ideal sound level.
Once you get this amplifier set up properly, it will keep your speakers thumping a long time. I tested it under a variety of conditions, and with different styles of music.
One issue that I’ve heard from lots of this amp’s users is that the remote bass control knob doesn’t work very well and often fails completely.
I’d recommend this amp to anyone who needs a simple amplifier to pump power to their subwoofers.
Luckily, this model is also produced in lower and higher wattages, so you can match a Riot series amplifier to pretty much any subwoofer setup to get the ideal power for your ideal sound.
It’s also a great budget choice, as it packs a lot of value at an exceptionally low price point.
FAQ & Buyer’s Guide
Installing Your Car Amplifier
I always recommend professional installation. Unless you’ve installed car audio before or have a friend who can serve as a very helpful guide, it’s worth the extra money to have a professional do your labor.
A bad installation can kill an amplifier before it ever gets your sound off the ground, and warranties often don’t cover damage you could cause by installing it in a faulty manner.
However, you have some work to do too when it comes to first running your amp. Once it’s installed, set it to a very low gain, turn it on, and start listening to music.
Slowly increase the gain until you get to your ideal sound level.
This puts an unnecessary strain on the amp that makes overheating more likely, and puts more wear on the all-important hardware inside.
Car Amplifier Longevity and How to Care for Your Amp
One of the biggest problems I see with car audiophiles is not putting the proper care and maintenance into an amp. This is a good way to lose money.
While amps made with better materials will last longer, if you abuse them, they’re not going to continue performing for long.
Think of it this way: car amplifiers are incredibly powerful devices that pull electricity from your car’s battery and convert it to sound.
There’s a lot of complex machinery in modern amps, and the process of converting pure electricity to audio energy produces a lot of heat.
There are so many things that can go wrong in this process that long-lasting, well-made amps are truly a marvel of engineering.
Overheating arises because of several factors:
- Running an amp at its maximum power every time you use it
- Using your amp frequently on very hot days
- Running your amp frequently for very long periods of time
I’ll address this again in the next section, on matching your amp to your speakers, but let me bring it up here, too: you want your amp to have a bit more power than you actually need.
Ideally, you should have your amp’s gain set to about 75% of the maximum when you’re using it. Therefore, you need an amp with about 25% more power than your speakers need to sound great.
Not running your amp on full blast all the time is the single best way to prevent overheating.
In addition, you don’t want to run your amp on very hot days or for extremely long periods of time. Most people keep their amps in the trunk, and the trunk gets hot when the weather is warm.
If you need to travel for a very long period of time or go out on a really hot day, reduce your amp’s gain a bit to keep it from running too hot.
A good metaphor for your amplifier is a marathon runner. Because a marathon is so long, runners don’t go at their top speed—if they did, they’d wear themselves out in the first few miles.
In addition, marathons are a lot harder during heat waves, and no one runs a marathon on Friday and then goes and runs too more on Saturday and Sunday.
Your amp is working hard to make your car audio experience great—the least you can do is take care of it.
Other Common Issues and How to Prevent Them
Besides overheating, the most common problem I see is amps getting wet.
You wouldn’t throw your laptop in the pool or pour lemonade on your PlayStation, so don’t let rainwater get on your amp.
Water and electricity don’t mix. Get your amp wet, and it shouldn’t be a shock when it stops working.
In addition to overheating and water, you’ll want to tightly secure your amp so it doesn’t move while you’re driving. Amps moving around in the trunk at best makes your amp look pretty beat up, and at worst can kill it completely.
Matching Your Amp to Your Speakers
There’s a lot of misinformation out there about matching amps and speakers.
Some people think that speakers and amps have to be the same brand to be compatible.
Some think that any amp will work on any speaker. All of these suppositions, though they’re somewhat popular, are incorrect.
In truth, there are a few key things to know about matching amps to speakers.
They’re not difficult, but getting any one of them wrong can make your setup less durable—or just make it not sound right at all.
- Matching the Wattage
Your amp’s wattage should be slightly higher than the combined wattage of all your speakers.
If you have two 200 watt subwoofers, like the Kicker box in my Subaru Outback, that totals 400 watts.
An ideal amp for this box would be somewhere in the 500-600 watt range.
You don’t want your amp to be too weak or equal in power to your subs, because then you’ll have to run your amp at 100% gain constantly to get the best sound.
This wears out the amp and makes it prone to overheating.
In addition to looking at an amp’s overall wattage, on amps with 4 or more channels you need to look at how much of that wattage is assigned to each channel.
is an important and often overlooked part of the combination of amps and speakers.
Cheap wiring, or wiring that’s too low gauge, will ruin the sound quality of even the best amps and speakers.
In addition, the way wiring is done can change the impedance—measured in ohms—of the system.
This can damage your amp or speakers and cause clipping and other issues, and is one of the main reasons I recommend professional installation of all car audio.
How Many Channels Do I Need?
This is one of the most common questions I get when friends and acquaintances ask about purchasing one of the best car amplifiers.
In truth, there’s no simple answer, but I’ll break down the basics for you here.
Four-Channel and Higher Amplifiers are intended for powering multiple speakers, which may include your door speakers and your subwoofers.
Amps with more than four channels are great for the latter, like the Pioneer GM-D9605 I reviewed above.
Two-Channel Amplifiers can be used to power both door speakers and subs, but are generally used for powering two or more subwoofers. Often, they are “bridged,” essentially making them a one-channel sub.
One-Channel Amplifiers are used to power a single subwoofer or multiple subwoofers wired together. This is my personal preference for powering a subwoofer setup, as it keeps things simple and provides clean, consistent power for thumping bass.
There are workarounds to getting an amp with the wrong number of channels, but they can be complicated and even reduce your amp’s longevity.
What Do All the Specs Mean?
If you’ve read this far, you know a bit about power, which is measured in watts.
More power means more volume, and too much or too little power can ruin the way your speakers and amplifier work together.
However, there are other specs that are a little more complicated, but just as important.
This includes impedance. Impedance, measured in ohms, is essentially electrical resistance: how much the power has to work to get converted into sound energy.
Lower impedance means that fewer watts will produce more volume, but it also reduces stability.
The impedance of the amp should always be equal to or lower than the impedance of the speakers.
The same rule always applies: always make sure your amp’s impedance is equal to or lower than that of the speakers.
There are other specs you need to watch out for, too, such as sensitivity and filtering.
Essentially, sensitivity still involves making sure that the sensitivity of the amp matches that of the speakers, because having a huge mismatch can create sound quality and performance issues.
All About Filtering
Filtering is important, too. A low filter, often called a lo-pass filter, is an absolute must for powering subwoofers.
This option filters out all sounds above a certain frequency, so that your subwoofer reproduces only the low end of your music. This is what gives subwoofers that distinctive bass response and thump.
Also, when you’re setting everything up, you need to make sure of a few things:
- that the subwoofer is wired into the channel(s) with the low filter
- that the low filter switch is on
Without filtering, your subwoofer will try to reproduce the whole sound of the music, including higher sounds like vocals. At best, this simply sounds bad. At worst, it can ruin your speaker.
Conclusion: Car Amplifiers
Normally when I make these top five and top ten lists, I try to set one option forth as the absolute best, and then pose a few alternatives for users with very specific needs.
However, with this car amplifier buyer’s guide, I’m going to put forth two top choices.
This is because amplifiers for subwoofers (1 and 2 channel amps) and amplifiers for whole systems (3-5 and above channel amps) are intended for completely different things.
If you only need to power subs, you don’t need those extra channels.
If you want to power door speakers or both door speakers and subs, there’s a whole host of different things to be concerned with.
The Best Amp for Subwoofers Is…
For my money, the Rockford Fosgate R500X1D is the best car amplifier for solely powering a sub box.
If you need less or more power for your current setup, check out the other models in the Rockford Fosgate Punch series—except for their wattage and size, they’re essentially the same as this model, and share all its key features and solid construction.
There’s a Punch amp out there that’s good for pretty much any need.
If You’re On a Budget
Though the R500X1D is a great value, it’s not the cheapest mono amp out there.
While many cheaper options on the market are very subpar or lack any sort of durability, the Boss R1100M is a truly effective but still much more budget friendly option.
Like the Rockford Fosgate Punch series, the Boss Riot series has a wide range of power levels, so if you need to power more or less on a budget, look at other options from the same series.
Top Amplifier for Door Speakers and Subs Is…
My favorite amplifier in this category has to be the GM-D9605 by Pioneer.
Its 5-channel setup is ideal for pushing power to all four of your door speakers and a subwoofer, and its compact design and extremely high quality of manufacture make it an ideal choice for changing your whole car audio sound for the better.
This amplifier truly feels like two different amps—a 4-channel for door speakers and a tough monoblock (1-channel amp) for a sub setup—perfectly fused.
The power of one isn’t sacrificed to make room for the other; instead, they’re both allowed to shine and thump.
If You Need More Power
If you have some space to work with and you want even more bump than the Pioneer GM-D9605 provides, Planet Audio’s AC2400.4 may be the better choice for you.
The only major reason I recommend the Pioneer offering over the Planet Audio is the AC2400.4’s lack of a fifth channel.
Having five channels—four for the doors and one for the subs—gives you a bit more control over your sound.
However, with the sheer power of the Planet Audio AC2400.4, you might not even notice the difference.
This thing has enough juice to bump some of the toughest subs out there.
How to Find an Amplifier for You
The most important aspect of finding the best car amplifier is matching it to your speakers properly.
A close second is the general quality of the amp. Here are a few good questions to ask yourself when reading about or testing out an amplifier:
- Is it made of good materials?
- Does it seem well manufactured?
- Does it suffer from audio clipping or other major issues?
Any of the amplifiers reviewed in this article could be great for you: it’s all about finding what amplifier suits your speakers and your tastes. I hope this buyer’s guide has helped, and that you find the best car amplifier for you!