great product
Crutchfield customer from Ojai, CA on 2/26/2021
Set up is real easy, wiring is nicely covered by the removable cover. Sound quality and construction quality is top notch. Pending a need for another amp I would just buy a second one of these.
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0 of 0 found this helpful
JL Audio XD400/4v2
Crutchfield customer from Miami, FL on 9/17/2020
One of the best amps I've ever had. Small, compact ant powerful
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0 of 0 found this helpful
Non existent distortion!
Guest from San Antonio, TX on 8/25/2020
I used to hear distortion turning my volume up only 75 to 80% with my old Focal amp before I blew it. After buying the XD400, I can now turn my volume up 95 to 100% without hearing distortion and hear details from my Focal components that I never heard before. This amp is the baddest amp on the planet in its size class! With the rollback protection that only comes in JL's XD amps, you can abuse your mid and highs for hours with crystal clear clarity!!!
Pros: Small. Powerful. Clear. Reliable. Easy connections and tuning. Stays cool enough to power speakers for longggg road trips even with hours of abuse!
Cons: Maybe a tad expensive. Make sure your components can handle the power because they'll blow before this amp does!
0 of 0 found this helpful
JL Audio XD400/4v2
Crutchfield customer from Vineland, NJ on 8/1/2020
2014 Chevrolet Camaro
Added this amp to my 2014 Camaro 2SS with stock Mylink/BA speakers also with the Kicker 10" sub option... Simply amazing.!! Will upgrade component and rear deck speakers shortly... Can't wait.!!
Pros: Fits stock location...
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1 of 1 found this helpful
Great!
kevin from Alpharetta, GA on 7/18/2019
I waited a bit to write a review for this because I really wanted to work it hard on a long trip. I recently took a trip from atlanta to jacksonville and this amp pumped hard the whole way! Totally worth the extra little money. I recently had another amp in my last vehicle that made all kinds of noises and would overheat if turned up too loud for too long. Not this amp!!!
Pros: Great Endurance
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1 of 1 found this helpful
JLAudio:XD400/4V2 amp., JLAudio: C525x speakers
Crutchfield customer from Los Angeles, CA on 4/23/2019
I have been an audiophile for forty years. I never gave much attention to auto stereo, simply because it was to boomy. The highs were to bright the mids not detailed enough and the lows distorted. One would ended up with listening fatigue. Well looks like technology has come a long way the results of my: JL Audio XD 400/4V2 amp in conjunction: with the: JL Audio C525 x Evolution speakers have done just the opposite. For what it is, naturally it's not to the degree of home audio but the sound is musical and inviting. Height are natural mids are detailed and the lows a tight. I will be shortly upgrading to a new CD player (Pioneer Stage4 DEX P99 RS) and expect to achieve a more 3 dimensional image
Pros: All good
Cons: None
5 of 5 found this helpful
JL Audio XD400/4v2
Crutchfield customer from Stockton, CA on 1/29/2019
Verry happy with my purchase and promp delivery
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1 of 1 found this helpful
I love this amp.
Justin from Niceville, FL on 1/13/2019
As stated in the title, I love this amp. I have owned it for three years now and I can't believe the amount of abuse it has taken without a hitch. I've had it installed in three different vehicles now, all with different sound systems. Absolutely amazed with the amount of power this can kick out from such a small package. Easy to install, easy to tune, easy to hide, I just can't think of anything wrong with it. I can't recommend this enough.
Pros: - Stays cool. - Easy to hide due to small footprint. - Sounds great. - Hardy, has taken quite a beating over three years with no issues.
Cons: - Expensive.
3 of 3 found this helpful
JL Audio XD400/4v2
Gerald from Mays Landing, NJ on 10/19/2018
This small amp is a powerful enough to power 4 component speakers with 75 watts RMS per channel with clear sounding music. I don't have a need for anything more than this little bad boy puts out!
Pros: Small size and clean high power
Cons: None

1 of 1 found this helpful
JL Audio XD400/4v2
Daniel from Austin, TX on 5/8/2018
Really good in tight spaces. Quality is always what you expect from JL
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2 of 5 found this helpful
JL Audio XD400/4v2
Crutchfield customer from Hercules, CA on 6/15/2017
2 of 5 found this helpful
JL Audio XD400/4v2
Jason from Jackson, MI on 5/10/2017
So far so good. It's only been installed for a week but it works very well. I previously had the 300/4 which dropped the right rear channel. I had it repaired by the factory and it lasted a couple of years and dropped that channel again and took the speaker with it. I'm hoping the XF400/4v2 holds up better.
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4 of 5 found this helpful
JL Audio XD400/4v2
Richard from Silverton, OR on 3/5/2017
I love this amp! It is half the size of most that put out the same amount of power & draws less on your battery. The sound is clean and the range is fantastic.
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6 of 7 found this helpful
JL Audio XD400/4v2
Steven from Roseville, CA on 3/5/2017
I had one of these on my Harley Davidson very small compact with a lot of power. Sounds really good. So I purchased a second one for my Harley Davidson say motorcycle so I have two of these jail audio 400 W four channel amplifier's parents six JBL marine speakers on my Harley Davidson.
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1 of 6 found this helpful
Incredible Performance and Quality
Crutchfield customer from North Aurora, IL on 1/31/2017
These amps with new technology are impressive, gone are the days you need a 3 foot long amp to get power and quality. I've owned Alipne, Kicker, MTX, Rockford, PPI, Soundstream, ADS, Hifonics, Pioneer, acoustic, Sony, Profile, amps and I keep going back to JL Audio. I'm hooked for life, just can't beat them.
Pros: incredibly small footprint, amazing sound quality
Cons: made in china
9 of 11 found this helpful
Costly but worth it!
Mar from San Francisco CA on 4/11/2016
I initially had a 4 channel Pioneer amp which I was told would be sufficient to run my Alpine component speakers and Pioneer head unit. I would say for awhile it ran fine but I began to notice some issues with it. I heard static/buzzing noise coming from the tweeter and the sound kept fading from right to left. I eventually brought to the place I had the amp and speakers installed and he told me that the amp was under powered. I still don't know why he didn't tell me when he installed it originally. He recommended I get the JL Audio XD400/4v2 amp. The sound sounds cleaner and tighter. The installer told me not to underestimate the amp. The worse that could happen is that I blow out my components before the amp.
Pros: Cleaner and tighter sound for such a small amp. It's JL..enough said
Cons: Costly but worth it
7 of 7 found this helpful
Great Amp
Bill from san jose, CA on 2/9/2016
I wanted to upgrade the stock stereo in my 2008 Lexus. I started with a Kenwood head unit, which improved the functionality (Bluetooth, phone, UBS, etc) but the sound wasn't much better. I installed Focal 165 front speakers running off the Kenwood head unit amp. The sound was worse than it was with the factory speakers! The speakers distorted and crackled, even at low volume. I assumed that the speakers were faulty. However, my local installer said the Kenwood amp was not adequate to provide a clean signal to the Focal speakers. He recommended this amp. He was right! The Focal speakers superb, driven to perfection by this amp. In addition, I installed a subwoofer. It's also powered by this amp, and sounds great. My message to unsophisticated buyers (like me) is to forget about powering good speakers with a head unit amp. Invest in a high quality, high power amp like this one, and you'll enjoy a great sound system.
Pros: A perfect match for high quality speakers, and subwoofer.
Cons: None.
7 of 7 found this helpful
Big Power, Small Size
John from Simi Valley, Ca on 12/17/2015
This amp is my second JL amp in this model, it's silent, pumps out crazy power and never gets too hot! I would definitely buy this amp again!
Pros: Small size, runs at a cool temperature, amazing power output, and no bright unnecessary lighting
Cons: none
10 of 10 found this helpful
jl audio xd400/4v2
Mike from Roseville,MI on 12/8/2015
This is my very first amplifier from jl audio and very much impressed with the clean sound and quality from this company. The highs,mids and lows come thru flawlessly. It is hooked up to the pioneer deh-x9600bhs head unit along with the pioneer ts-d6802 in the front doors along with the alpine type-r 68 speakers in the rear deck of a1999 ford crown victoria (non-police package). Knowing how clear/clean the sound quality is it is a very powerful amplifier and would highly recommend this amplifier to anyone
Pros: Powerful clean and clear sound quality
Cons: None what so ever
8 of 10 found this helpful
Pppow, power for Thumping Base and Silky-clear Highs
Doug from Oregon on 6/1/2015
Plenty of power to round out even the most dynamic of passages delivering thumping base and silky highs while quiet with low signal to noise ratio and almost no detectable distortion. This Class D amplifier sips power & won't leave you drained and stranded while parked and cranked! I'm not disappointed and you won't be too.
Pros: Powerful, quiet, compact, wide dynamic range and doesn't throw a lot of heat.
Cons: none
15 of 15 found this helpful
Amazing Compact Amp
Joe from Augusta, GA on 5/4/2015
This amp is very compact and packs quite a punch! I am driving four JL C2-650's, components up front and coaxials in the rear doors. I am using a JL 500/1 driving a Stealthbox and it all ties together perfectly. My stereo will ruin your hearing now with amazing clarity. I strongly recommend this amp!
Pros: Compact, powerful, well made, distortion free
Cons: None really other than the price being slightly high but you get what you pay for...
10 of 11 found this helpful
Very nice, well-controlled sound
Chris B. from Texas on 3/8/2015
This amp rocks. I've always swapped out factory speakers, but never installed an aftermarket amp. That approach didn't work too well in my new Accord. So, I bought an Alpine MRV-F300, which had a nice price, but pretty awful sound, at least to me. I wanted something that was more musical. And because I'd already run an 8-gauge power cable for the Alpine, I wanted something that would work with that, so I returned the Alpine and got this. In the end, this JL amp is fed through an AudioControl LC6i and is driving four Alpine SPS-610 coaxials. The sound is really good, though I will eventually upgrade the speakers to something more worthy of this amp.
Pros: surprisingly musical, compact and can run off smaller power cable
Cons: pricey to me
10 of 10 found this helpful
Amazing amp
Crutchfield customer from Upland, ca on 5/25/2014
It is an amazing amp for it's size. I used it to power my sub and two tail gate speakers for tail gating and is perfect.
Pros: Size vs power ratio
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3 of 5 found this helpful