Whether you’re looking for sound quality, high output or budget friendly choices, I will break down the options and show you the best car amplifier for your needs.
Estimated read time: 4 minutes 30 seconds. Want to read later?Car amplifiers can generally be broken down into 3 categories:
- Mono or single channel amplifiers – used for subwoofers
- 4 channel amplifiers – used for interior speakers
- 5 channel amplifiers – used for a combination of interior speakers and subwoofers
When shopping for the best car amplifier, it is important to pay attention to the following specifications:
- RMS power ratings
- Total Harmonic Distortion level or THD
All the amplifiers I recommend here are excellent quality. You will see they have relatively low total harmonic distortion level, typically less than or equal to 1%. They’re also rather efficient and come in a compact size. I’ve also listed physical dimensions for your reference as well.
Check your specs
Note, all of the amplifiers I recommend follow CEA-2006 Compliance regarding RMS rating guidelines:
- Number of Watts X Number Channels RMS @ Number of ohms at 14.4 volts
Make it a point to look at an amplifier’s RMS power rating and see at what impedance or ohms it is rated at. Some less than stellar car amplifier companies out there will advertise an unrealistic power handling rating just to grab your attention. Oftentimes it’s only when you look at the owner’s manual do you find these ratings are listed at an unrealistic impedance such as .5 or 1 ohms.
For interior speaker amplifiers, generally speaking, you’re always going to be running the amp at 4 ohms. For subwoofers, you want your final impedance to stay in the range of 2 to 4 ohms. Anything less than 2 ohms is typically too little resistance for an amplifier to handle effectively. When you run a car amplifier below the specified impedance capability, you risk both sound quality and damage to your amp.
So pay close attention to those RMS ratings when shopping for an amplifier. For reference, RMS stands for Root Mean Square. Simply put, it is an approximation of continuous average power.
Power vs Size vs Sound Quality vs Budget
For this post, I’ve included a basic $ rating system in the amplifier comparison charts to give you an idea of cost against power, overall size and sound quality. Here is the key for that simple rating system:
- $ = $75 – $150
- $$ = $150 – $250
- $$$ = $250 – $400
- $$$$ = $400 & up
Best Mono Car Amplifiers
In the mono amp category, the more popular amps are in the 500 watt power handling range. In our shop we sell both the JL Audio JX 500/1D and the Alpine MRV-M500. Either amp is a great choice when you need a 500 watt mono car amplifier. If you are also installing the optional bass knob, JL Audio’s RBC-1 is slightly easier and cleaner to install. It’s slightly smaller so it’s easier to dismantle and mount in a stealth manner than Alpine’s RUX-KNOB.
If you need something slightly more powerful, like in the 600 watt range, I recommend the JL Audio XD 600/1 v2. It’s a great compact little amplifier that is very efficient and reliable. For a 1000 watt RMS mono amplifier, consider the JL Audio JX 1000/1D. The JL Audio JX 1000/1D puts out 1000 watts RMS at 2 ohms, but only 500 watts RMS at 4 ohms. Alpine’s PDX-M12 on the other hand has a regulated power supply and will consistently put out 1200 watts RMS whether you have a 2 ohm, 3 ohm or 4 ohm load. If you need a high output mono amplifier with a small footprint, the Alpine PDX-M12 is the way to go.
Best Car Amplifier – Mono up to 500 watts RMS
 |  |
|
|---|---|---|
| RMS @ 2 ohms at 14.4 Volts | 500 watts | 500 watts |
| RMS @ 4 ohms at 14.4 Volts | 300 watts | 300 watts |
| Bass Knob Ready | Yes - RUX-KNOB | Yes - RBC-1 |
| THD | <1% | <1% |
| Physical Size L x W x H | 7-7/8'' x 7-7/8'' x 2-3/16'' | 7-11/16" x 7-13/16" x 2-1/8" |
| Gauge Power Wire Recommended | Minimum 8 Gauge | Minimum 8 Gauge |
| Price | $ | $$ |
Best Car Amplifier – Mono up to 1200 watts RMS
 |  |  |
|
|---|---|---|---|
| RMS @ 2 ohms at 14.4 Volts | 600 watts | 1000 watts | 1200 watts |
| RMS @ 4 ohms at 14.4 Volts | 400 watts | 500 watts | 1200 watts |
| Bass Knob Ready | Yes - HD-RLC | Yes - RBC-1 | Yes - RUX-KNOB |
| THD | <1% | <1% | <1% |
| Physical Size L x W x H | 8-1/2'' x 7-1/8'' x 2-1/16'' | 10-15/16" x 7-11/16" x 2-1/16" | 10-1/8'' x 7-9/16'' x 2'' |
| Gauge Power Wire Recommended | Minimum 4 Gauge | Minimum 4 Gauge | Minimum 4 Gauge |
| Price | $$$ | $$ | $$$$ |
4 Channel Amplifiers
When shopping for a 4 channel amp, keep in mind, there is actually a sound quality difference between amplifiers. Take these three amps for example:
- Alpine KTP-445U (45 watts x 4)
- JL Audio XD 400/4 v2 (75 watts x 4)
- Alpine PDX-F4 (100 watts x 4)
All of these amps are great options with various power handling ranges. They’re all compact and efficient. The KTP-445U is the most compact and efficient of all. Aside from power output and physical size, there is also an audible sound quality difference between all of these amps.
If you were to compare the KTP-445U to the built in amplifier of an Alpine head unit (about 18 watts x 4 RMS) you would notice a considerable difference in output, clarity and vibrancy. Yet, when compared to the JL XD 400/4 v2 amplifier, the Alpine KTP-445U sounds rather flat. If you had the opportunity to listen to these car amplifiers on a sound board (like I do) you would notice the XD 400/4 v2 sounds more lively and vibrant. If you then compared the JL XD 400/4 v2 amplifier to the Alpine PDX-F4 amplifier you would find the PDX-F4 is even more vibrant and has greater detail and subtle nuance.
Best Car Amplifier – 4 Channel
 |  |  |
|
|---|---|---|---|
| RMS @ 2 ohms at 14.4 Volts | 90 x 2 (bridged to 4 ohm load per channel) | 200 x 2 (bridged to 4 ohm load per channel) | 200 x 2 (bridged to 4 ohm load per channel) |
| RMS @ 4 ohms at 14.4 Volts | 45 Watts x 4 | 75 Watts x 4 | 100 Watts X 4 |
| Sound Quality Rating | 6/10 | 8/10 | 9/10 |
| THD | <.03% | <1% | <1% |
| Physical Size L x W x H | 7-7/16'' x 1-1/2'' x 2-1/12'' | 8-9/16" x 7-1/8" x 2-1/16" | 10-1/8'' x 7-9/16'' x 2'' |
| Gauge Power Wire Recommended | Minimum 18 Gauge | Minimum 8 Gauge | Minimum 4 Gauge |
| Price | $ | $$$$ | $$$ |
5 Channel Car Amplifiers
5 Channel car amplifiers are a convenient option for anyone looking for a space saving, total system amplifier. In my shop, we sell both Kenwood and Alpine 5 channel amplifiers. The major differences between these 5 channel car amplifiers is their power capabilities and overall size. They all have great sound quality and provide warm, rich and natural tonal qualities. The Kenwood has a very small footprint along with pretty impressive power output – note there is no optional plug in bass knob for the Kenwood. If you purchased this amplifier, you could always install a universal bass knob, like the PAC Audio LC1. That’s what we do in our shop when we sell and install this amplifier.
Best Car Amplifier – 5 Channel
 |  |  |
|
|---|---|---|---|
| RMS @ 2 ohms at 14.4 Volts | 90 watts x 4 + 350 watts x 1 into 2 Ohms | 75 watts x 4 + 600 watts x 1 | 100 watts X 4 plus 500 watts x 1 |
| RMS @ 4 ohms at 14.4 Volts | 60 watts x 4 + 250 watts x 1 into 4 Ohms | 60 watts x 4 + 400 watts x 1 | 100 Watts X 4 plus 500 watts x 1 |
| Bass Knob Ready | Yes - RUX-KNOB | No | Yes - RUX-KNOB |
| Sound Quality Rating | 7/10 | 8/10 | 9/10 |
| THD | <1% | <1% | <1% |
| Physical Size L x W x H | 10-5/8'' x 9'' x 2-1/4" | 10-1/4" x 6-5/8" x 2" | 10-1/8'' x 7-1/2'' x 2" |
| Gauge Power Wire Recommended | Minimum 8 Gauge | Minimum 4 Gauge | Minimum 4 Gauge |
| Price | $$$ | $$$ | $$$$ |
Conclusion
As you can see, there are a variety of choices and options out there when shopping for the best car amplifier. Space constraints, desired RMS power output, sound quality and budget can all factor into your decision making process when selecting the best car amplifier. I hope this post has made it a little easier to select the best car amplifier for your unique needs and vehicle application.
Still confused about the best car amplifier for your needs? Feel free to post a question in the comments and I’d be happy to clarify any details and answer any questions. Thanks for reading!
21 Comments
Hi Annie,
What do you think about the Alpine PDX-5 AMP?
It’s a great amp, but not as good sound quality as the newer version PDXV-9.
Hi Annie,
I just purchased a 2016 Wrangler Unlimited and I need some music! I plan on replacing the head unit with the Pioneer 4100 you turned me on to, and I am planning on running two JL 10W3, and thinking 2 sets of JL C2 650, or maybe one set of these and then a set of the C2 650 X in the sound bar. Any thoughts on the speakers? Also, would you recommend the JL HD 900/5 or the Alpine PDX V9. They look similar but the Alpine is budget frinedly right now. It has been several years since I played in this world so I really appreciate any help/guidance!
Thank you!
Chantz
Hi Chantz – congrats on the new Jeep! Check out the 2016 model AVH-4200NEX and the iDatalink maestro RR with CH1 you will get more cool features (like check tire pressure monitoring on screen and read/reset vehicle error codes). Speakers – Yes, suggestion – Morel. Did you see my Jeep stereo system write up? Check it out. And amplifier – Alpine PDXv9. I know it’s cheaper, but I think it’s also better. JL makes GREAT subs and they do make good speakers and amps, but subwoofers are their strength. With Alpine, amplifiers are their strength. With speakers, Morel is what we recommend and guess what, that is all Morel makes. Cherry pick my friend, take the best of the best.
I am planning on getting the Lightning Audio L0-2X12
Sealed subwoofer enclosure, it has an rms of 300watts, and an impendence of 2 ohms, and I was wondering what amp I should get. I want to keep the amp within a reasonable price range, but still get the most out of my subs. Thanks!
Hi Blake,
I would go with the Alpine MRV-M500. Hope that helps!
Hi Annie! I’m planning for a 3-channel system consisting of a Kenwood excelon kdc-x998, Alpine PDX-F4 (one channel bridged for sub), JL audio 8w3v3 microsub 4ohms(http://intl.jlaudio.com/cp108lg-w3v3-car-audio-microsub-subwoofer-systems-93133). Though, I can’t decide for the speakers. Can you suggest any? I want a system that sounds accurate and clean like a reference system. Thanks!
Hi Regie,
I always recommend to customers to cherry pick the best among the best. I would go with Morel speakers. Depending on what your budget is, they have a variety of speakers to choose from, but honestly they all sound really good! The higher up the line up you go, the more accurate and dialed in or tight the sound is. At our shop we show and sell the Maximo series, Tempo series, Virtus series and Hybrid series.
I just purchased two boss phantom 12″ subs dual voice coil. 2300 watts a piece. I’m also gonna use 6 1/2 door speakers and 4 inch dash speakers. This is going in Toyota 4×4 extra cab pickup. What would be good amp to use? Never bought amp before so I’m going at this blind any suggestions?
Well it looks like those subs are capable of 1150 watts RMS a piece so you would need probably two amps, one amp for each sub capable of producing 1150 watts RMS at 2 ohms (assuming you have the dual 4 ohm subs). Alpine has a nice mono amp 1200 watts RMS, the PDXM12.
Hi Annie,
Thanks for the great info! I discovered that the enhancer was enabled. I turned all that off this morning, and turned off the speed-sensitive volume too: big difference, even for the local FM station.
I think I will follow your recommendations and start with the speakers/amplifier before deciding if I need something like the Cleansweep DSP.
I hear you about the Dynamat and Subarus, I did that to the previous car. Best thing I did was Dynamat the doors, and add extra rubber gaskets between the inner door skins and and the door panels when putting it all back together. I also took the a-pillar panels off and replaced the thin cloth-like gaskets with rubber-foam ones. No more annoying panel and dash squeaks/rattles when the weather got cold! It was always one of those things you would chase: in the heat of summer – relatively quiet. Then freezing temps would hit and there would be rattles and squeaks all over. Will be doing the same to this one, even though I do find the fit/finish much better than it was in my ’09.
Now I just have to find a mosquito-free environment to do the installation work in… 🙂
Cheers,
Stephane
Hi Annie,
I think your site is pretty awesome! I’m looking for a little advice. I didn’t purchase the dealer-installed Kicker speaker and powered sub upgrade for my new vehicle because I read all over the forums that I can do better for less money. I want to keep the factory head-unit (a Clarion touchscreen that interfaces nicely with the steering wheel control, bluetooth setup, rear-view camera, and aux/usb ports). For speakers I am considering pair of Alpine SPR-60 coaxials for my rear speakers and SPR-60 components up front. I’ll be using the stock speaker locations – including the in-dash tweeter location.
For the amplifier, I have gotten differing opinions: (a) I could use the new speakers without an external amp for now, or (b) get an amplifier right away. From my research, it sounds (no pun intended) that I should get the amp right away not to damage the Alpine’s. The difficult part is trying to figure out which 4-channel amplifier to use. I’ve had different recommendations:
Alpine KTP-445U
Rockford PBR300X4
and my local shop said: get a 2-channel amp and power just the front stage.
Other recommendations have been the JL Audio JX400/4D and Alpine PDR-F50.
What do you think? I want to install the amp under the passenger seat and at some point I will add a powered sub. My listening habits don’t include blasting the h_ll out of the music: I’m looking for accuracy, detail, and clarity. I listen mostly to rock, blues, jazz and alternative and unlikely to play any classical in the car! 🙂 Sources includes CD, USB/iPod/Bluetooth (digital), FM and some satellite listening.
Any input would be appreciated…some of the recommendations are 50W, some closer to RMS rating of the speakers (100W). Some are class D, some class BR, and I’ve been also recommended a RF Punch 600X4 that’s class AB. It gets all a little confusing – starting to wonder if I should have just paid for the Kicker upgrade and called it a day. 🙂
Thanks,
Stephane
Hey Stephane – I’m happy to weigh in here, but can you tell me what year, make and model vehicle?
Hi Annie,
The vehicle is a 2016 Subaru WRX Sport. Subaru needs to be slapped silly – they make a great performing vehicle, include pretty good controls and interfaces. And then put the lamest speakers in it. 🙂
Thanks for any help – I was on a road-trip to Montreal this past weekend to see U2 and we just kept shutting the stereo off. Just not worth listening too with the stock speakers.
/Stephane
Hi Stephane – first off, I’ve had a few people complain to me about the newer Subaru sound systems and I actually just had a chance to play around with one last week and here’s what I found. In the EQ menu there is something called like “Sound Enhancer” or “Sound Expander” something like that below the EQ option. Make sure that crap is turned off. All it does is boost a lot of low end because I think Subaru assumes EVERYONE and their brother listens to extremely compressed music. That expander might work well for SiriusXM, but it made everything else sound like a$$.
Type R’s are pretty good and they’re pretty efficient. They’re not as clean in the mid bass as something like Morel Tempo series, but still very good option.
If you’re going to use the stock head unit, in an ideal world you would use some type of audio processor like a JL Audio Cleansweep or Alpine PXA-H800, but it doesn’t sound like you’re looking for PERFECT sound, just a huge improvement. These types of processors allow us to correct and clean up the output coming from the stock stereo. If anything, do the speaker and amp upgrades and then assess the sound quality to see if further refinement is needed.
Otherwise you can go high level in. I do like the Alpine powerpack as it is a small, efficient and clean sounding amp. It is only 45 x 4 RMS though and if you do like it loud, you’re better off with something a bit beefier, especially since the Type R’s can handle it. I would probably go with the PDX-F4. That is one of the cleanest, warmest most vibrant class D amps I have ever heard. Second in line would be the XD 400/4 from JL Audio. The Alpine is 100 x 4 RMS and the JL Audio is 75 x 4 RMS.
With either you’ll need a line output convertor. I like the Pac Audio LP7-4.
And yes – at some point definitely add a subwoofer! For the cleanest sound, I prefer JL Audio. They’re like the only car audio company that still makes subs in America and you can hear the difference. And while you do the speakers load up on Dynamat, it makes a HUGE difference. Especially in Subaru’s. I hope that clarifies things for you!
I have 2 jl w0 v3-4. I have a 1 PPI ba 1000.4 amp and 2 PPI ba800.2 amp. I also have 2 rockford fosgate r2d4 12s. What is the best way to install.
Hi Kenton,
You don’t. That is if you care about how it sounds. Whenever you have different subwoofers and different amplifiers you have to worry about different efficiencies. No two subwoofers will hit exactly alike unless they are identical and being fed the identical information and power from the same amplifier. Once you start messing around with different subs and different amps you will be introducing different efficiencies meaning the subs won’t hit and play at exactly the same time.
When you do that you have to deal with frequency cancellation. The subs may end up hitting at slightly different times (I’m talking milliseconds) but remember subs are playing wavelengths. Like ocean waves. If one wave starts slightly later than another the peaks and valleys are no longer in sync and your bass is no longer as powerful as it would be if they were in sync.
If the peaks and valleys are occurring at different times you essentially can put that frequency out of phase. You cancel it out. That’s how noise cancelling technology works. It plays the frequency you want to eliminate with the correct timing that essentially puts the unwanted frequency out of phase and cancels it out. Just don’t do it. Unless you just want loud crappy bass and don’t give a hoot about sound quality, then you can do whatever you want. Hope that helps.
Hey Annie,
What do you think about the new alternatives to the Alpine KTP-445U from JL (JL Audio HX280/4) and Kicker (Kicker 42PXA3004)? I saw you had a post about the new JL amp, but how do either of the 2 new compact amps compare to a traditional 4 channel amp? With the JL putting out 70Wx4@2 ohms and the Kicker putting out 75Wx4@2 ohms, how difficult is it to run door speakers at 2 ohms? It seems like the ability to run these amps at 2 ohms and a higher power output is the main advantage over the alpine amp. I would be running a set of Infinity components rated for 2 ohms.
Thanks,
Mike
Hey Mike,
You can bridge the Alpine if you wanted for 90 x 2. That’s kind of cool. Anyways, yeah those JL HX280/4 have been really hot sellers, can’t keep them in stock and JL can’t seem to keep up with the demand. I got a couple in late December, I ordered them in the beginning of the month and sold them pretty much as soon as they came in. Placed another order and just got word that back order is FINALLY shipping this week. So I haven’t had a ton of time to play around with them.
One thing I really like about the JL amps is they are truly Marine grade and waterproof (even the regular non marine ones) so it’s a bit more flexible in application and I think can stand up to more abuse than the Alpine. JL has also always been known to make good, clean amps like Alpine, but I have a feeling the JL probably sounds better, but personally have not had a chance to really listen and compare.
Never been a huge fan of Kicker and don’t have any recent hands on experience with that product so can’t really give you answer on the Kicker amp.
And it’s not so much about running door speakers at 2 ohms – you’ve got some limited options, you’d need to use door speakers rated at 2 ohm like the JBL speakers I just did a review on or the Infinity components you’ve got. Alternatively you can also bridge the JL amp and have it push 140 x 2 RMS to a pair of 4 ohm front door speakers speakers.
These newer compact amps are impressive. I like them for a few reasons. Flexibility in installation, easier to install, efficiency, compact, good value. I would compare them in sound quality to the Alpine entry level V-power amps or the JL JX series. So I do think you can get richer, warm sound reproduction with a more traditional amp like an Alpine PDX-F4 or JL XD 400/4, but there is a definite cost factor for many. You get what you pay for and those amps will provide a warmer/richer more natural tone in my opinion, but they cost more and take a bit more effort to install, so it’s a trade off.
Hi Annie !!
I have a 06 xb and I want install
2 L7 kicker 15″
DC 2k amp
2 momo set MMC5250
P400-4 Rockford fosgate
wire gauge 0 300 amp stinger fuse
RCA monster cable
do I need upgrade the alternator ?
for how many amp the alternator could be good ?
Its my rpm on my car going to be high ?
do I have the right number on my fuse ?
What battery do you recommend and alternators ( brands )
Hi Carlos,
It depends on what impedance you plan on running that mono amp at. Assuming you run the mono amp at 1 ohm, I would definitely upgrade the alternator and probably put in a second battery just for the system with a battery isolator. I don’t sell alternators, but I can tell you it’s never usually a good idea to buy a remanufactured one. Try to find the highest amperage possible like 320 amp or higher would be good. We use interstate batteries at our shop.