Decided to buy this amp after upgrading to a JL audio XD700/5v2 amp to replace smaller alpine power pack in my truck and realizing I wanted a real amplifier and that my speakers wanted the power. After seeing the massive upgrade the XD was I decided to go fully active and purchased this HD 600/4 amp! Talk about clean! Full! Headroom and power! Make sure you've got a good battery to feed this amp and you will absolutely be happy! I'm pushing Focal K2 6.5" woofers and a JL 8w3v3 on the other two channels bridged with this amplifier and I gotta say I've never heard a better system currently than I have now! Love this amplifier with the XD amp pushing my mids and highs and a focal flax 8" subwoofer... I know this is a review on the HD 600/4 and I highly recommend it but I also HIGHLY recommend all these components that I've listed and currently have running in my Toyota Tacoma
Pros: Power; efficiency; small; headroom; extremely clean!
Cons: U get what you pay for! None
1 of 1 found this helpful
WOW. After 8 years, I just upgraded from the XD400/4 (the best bang for the buck amp on the market) to this HD600/4. The Headroom seems unlimited, and the Clarity is fantastic. It does seem to run hotter, but Stellar Performance here on day one, and worth every penny! I listen to Hard Rock and Heavy Metal, and this is the first time I've ever considered that I may need MORE SUB to keep up with the speakers. Installed in a midsized hatchback.
Pros: Exceptional Performance. Amazing Headroom to just keep going louder and louder without sacrificing clear and clean sound. SMALL FOOTPRINT.
Cons: Expensive, but worth it, and runs a bit hot.
1 of 1 found this helpful
Drives my Morel and Hertz speakers with ease. High power no distortion. Easy to install and tune.
Pros: Small foot print, big sound!
Cons: Price, a JL trademark
1 of 1 found this helpful
I bought this amp to push my c5-653 components. And holy hell between the two of these they seriously scream! Would suggest these HD amps to anyone. I came from the slash series I've had for YEARS. great amp and low profile.
Pros: Great small profile. Big power
2 of 2 found this helpful
For an expensive 4 channel car amplifier you would think the sound would take your breath away if connected to decent hi-end quality speakers. For the JL HD600/4, I feel this is not the case at all. Like the other reviewer said I was left scratching my head trying to figure out why the sound was just mediocre - just meh. Any lesser quality A/B amp would definately outshine the JL HD because I feel it lacks fullness and instrument realism. I had tuned and played with crossover points, db levels, and equalized my head deck (80prs) for hours trying to figure out why my music wasn't producing the results I wanted. It was like everything was flat. There was no depth to live instruments or fullness- something was lacking. I eventually gave up with the JL HD series and installed and another amp.. immediately the music came to life but was still lacking some depth and realism ( had some serious kick in the low end - but the highs were a bit fabricated). I then took the chance and went with the Kenwood Excelon XR400-4 ( yes a Kenwood - I thought i would never say that) and HOLY COW.. like night and day. The Kenwood outperformed the JL HD600/4 in every aspect in terms of depth, fullness, realism, dynamic, punchy, and crisp! The Kenwood also had NO NOISE! NONE.. something the JL HD had especially at higher volumes. Save your money and put it towards an Excelon if you are looking for a quality Class D Amplifer that sounds waay better & less $$!!
Pros: Extremely Efficient! , Size, Durability, Play at either 4 or 2 ohms with same specs, Crossover points, Heavy
Cons: Sound.. it's lifeless, Tinny, Noisy, Cannot hear certain cymbals especially at higher levels, not as full or dynamic as other less expensive brands ( ie: Kenwood XR), stale for a very high priced amplifier
8 of 22 found this helpful
Really improved my system with this Amp.
Pros: Improved my sound quality and gave my system increased volume.
2 of 2 found this helpful
Great amp! Easy to install and has some serious power.
3 of 3 found this helpful
I own an 2014 Mercedes ML63 naturally came with a pretty decent H-K 14 speaker/830 watts surround system - per factory specs. But, well, thought I would treat myself to an upgrade since my car is the only place a hang out in my own, as it were. So, got a FIX 82, JLA HD 1,200/1 into 2x JLA 12" W6s in custom sealed enclosure and a set of JLA C5 653 3 way components for front staging/ JLA C5 650 2 way components for the rear driven initially by a JLA XD 600/6 (bridged for 200w/channel front and 75/w Channel rear). I did like what I got but felt the midrange was a tad raspy and got some distortion from the front stage. Shop kept telling me that the JLA XD 600 was as good as they come but I felt otherwise and requested a change to the JLA 600/4. So, now I can tuely attest that the HD deliver.... the mids and highs noticeably cleaned up - I also feel my ears were hurting with the XD turned up - no longer occurs with the HD600. The HD600/4 with the C5's is materially more "crisp", voices & instruments are a pleasure to listen to, etc... when compared to stock. Very pleased with this amp! Finally, as for the base out of the JLA HD 1,200? It truly pounds and produces increased air pressure inside the cab at 2/3's of the base knob turned up. Sealed enclosure also delivers "tight" yet pounding base. I like it! I am 49 and had not invested in an aftermarket system for decades - since back in the day of the Fosgate MOSFET Power 1,000 etc. It's all come a long long way, lovely amps.
15 of 15 found this helpful
I've been using this for a year and love it. I run a JL stealthbox and a three way focal set with it. It's silent where it should be and extremely loud where it should be. Very happy.
Pros: Loud, clean, sexy, dependable. Just like me.
Cons: Could be a little warmer.
6 of 6 found this helpful
i have 2 cars powered by these amsp about to have a third. one is a 2000 town car L model and its pushing 2 pair or morel virtus 602. the sound is amazing. the second is a 97 mark 8 lincoln. this car came with factory jbl separates. i had 2 pair of morel virtus 603 installed they surface mounted the tweets and used the facroty tweet postion for the 3.5 inch midrange. this is the only am i will run for any system. its incredibly loud and clear
Pros: best amp out there
Cons: dolla dolla bills....lots of hem
4 of 6 found this helpful
Well....if digital amplifiers sound like this I do not want any part of them. The high end sounded like there was a sheet of glass between me and the speakers. The amp did have some nice dynamic range and solid bass. But as a purist who simply wants a kick bass to sound like a kick bass and a cymbal to sound like a cymbal, this amp does not do it for me especially on the high end. My source of music are live recordings at 24 bit 192Khz.
Pros: Good stable power.
Cons: High end sounds like the cymbals are garbage can lids!
14 of 24 found this helpful
this amazing the power is unbelievable love it
2 of 5 found this helpful
These amps run cool, play hot, and are pure explosive fun! I've heard that class D amps are inferior, but after comparing them to my old A/B amps, I find no negative difference in musicality. At all! These bad boys are musical and extremely powerful, especially when you consider their size(think Ant-Man!) Thanks JL, for making my drive to and from work a blast!!
Pros: Size, Power, Musicality, Flexibility,
Cons: Not Available in Black??
8 of 10 found this helpful
I have a jl hd 600 running my system which is a set of focal 165 as3 components in the front stage and a jl audio 10 inch truck wedge behind seat and a kenwood x-998 hu and it sounds amazing , strong punchy lows sweet mids and smooth highs at any volume level
Pros: Plenty of power for size
3 of 4 found this helpful
I purchased this amp to power two sets of JBL 670GTI component speakers in my Jeep. These speakers are rated at 150 watts RMS/ch and 300 RMS per set, so I figured this amp would fit the bill perfectly. Now let me say that for the most part this amp made the JBLs sound very nice, but I like to listen very loud and the JBLs are competition speakers so they are meant to get very loud. The problem for me with this amp was that many times there ended up being something missing from my music. For example, when you would hear a cymbal or the snap of a snare drum, instead of it being nice and snappy and in your face it just sort of faded out into the distance. Same thing occurred with the vocals in many songs. Another thing that would happen often is when turning it up to a decent volume level, the vocals especially would start to break up. The overall sound is warm which is nice, but at the same time it makes most music sound almost lifeless and boring. Like one of the other reviewers had mentioned: it made me say "meh" and left me scratching my head. I know these speakers can play much louder without introducing distortion, and that is why I went with another amp. I returned this one and am currently auditioning a Rockford class AD hybrid amp. Once I hooked it up I noticed immediately that it was way cleaner and could get much louder before distortion was introduced. I am curious if going class AB is the solution to cleaning up the sound to the level that I am seeking.
Pros: Small footprint, lightweight, stays cool, extremely efficient, regulated power supply so impedance matching isn't much of an issue, makes your speakers sound great but only up to a certain volume level before distortion is introduced.
Cons: Overall sound produced by this amp tends to be lifeless and boring, do not get this amp if you really like to turn it up loud because distortion is quite easily introduced at high volume levels, especially with vocals and drums, certain elements of the sounds produced by this amp tend to fade into the distance making the sound seem unbalanced and flat
23 of 41 found this helpful
Great amplifier - best power in its class!
0 of 3 found this helpful
I'm gonna give it to you straight,because that's how I'd want someone to do me. If you are even considering this amp at all then buy it. If you have heard a slash series amp before then that's all great and stuff but the slash amps don't even compare to the HD series.. I'm the type of audiophile that won't quit until my stereo Sq is absolutely perfect. As good as Alpine pdx digital amplifiers were, I had to try the jl audio hd600. And once again no comparison. I had jl audio ZR650CSI components (front & back) and dynamated my whole vehicle and a hd750/1(which I did not like dew to no bass boost and lack of power. I bought 2 jl audio W7 10's but took them out because even though they hit extremely hard and drop really low, I found that they were a little sloppy for my taste due to the huge surrounds. I prefer tight, punchy bass so I dropped down to the W6's and they were much better. So u see I must have perfect and to me the Jl Audio Hd600/4 makes mediocre stereos sound ABSOLUTELY PERFECT! OMG! WOW! As jl audio claims, the HD amps actually takes the sound from your cd receiver and corrects the signal that you don't even realize needed any corrections and brings out brilliance that will actually approach the sound quality of home audio like Marantz, denon, Harmon kardon, onkyo, and klipsch which any true audiophile knows is nearly impossible to do in a vehicle. BUY THIS AMP OR NEVER HEAR TRUE BRILLIANCE! THIS IS AS HONEST AS I CAN BE!
Pros: Sonic brilliance! Buy it or regret it! Bring the sounds of Harmon kardon, onkyo, and klipsch to your car!
Cons: A little pricey but all the best stuff is! You get what you pay for really applies here!
22 of 25 found this helpful
Driving JBL 660gti components (150 rms each continuous, 600 watt peak each) and the sound is absolutely perfect, even at full power with no distortion. Replaced a Polk Audio PA660 and the sound is so clean and balanced now that I was able to completely clear all EQ adjustments (the PA660 required moderate treble boosting and mid-range pull down to be balanced). I've owned many makes and models of amps over several decades and the JL Audio HD series is by far, the cleanest sounding, easiest to install amps I've ever owned (have HD1200/1 driving a 13W7). While a little pricey, if you are running high end speakers it is definitely worth the money. Due to the power levels it achieves I do not recommend this amp for low end speakers.
Pros: Very easy to install and set via a voltmeter and test tone. Came with all necessary tools (except voltmeter and test tone). High power that is very clean and well balanced across the entire range. Compact and power efficient. Very robust and accurate built-in crossovers.
10 of 10 found this helpful
This amp is exactly what I hoped it would be. Very easy to install. Lots of power. My music is so loud and clean.
1 of 4 found this helpful
Amp is very strong, perfect for those screaming MIds and highs!?
Pros: Very compact for under seat mounting
7 of 7 found this helpful
This is truly an amazing amp. I have it hooked into a Kenwood 6190HD head unit and "stock" Dynaudio speakers. You have to give it time to break in. But when it does, it sings. The control is amazing. Imaging is fantastic. Voices and instruments hang in the air like they would in a high-end home audio system. I like road trips now, because I get to listen to my music on this gear. Very pleased.
Pros: Amazing sound and control. Not too large. Runs pretty cool.
Cons: Takes some time to break in.
7 of 13 found this helpful
started off with the hd1200/1 for my 13.5W7AE. blew me away, then i decided to buy this amp for my CDT HD series speakers. what an amazing difference this amp made in my vehicle. after putting this amp in you can clearly tell that my speakers are getting super clean power. setup is a breeze, amp is small, and 150 watts x4 RMS is plenty. the clarity is unbelievable with my EQ settings "Flat." sure its expensive but ive never looked back
Pros: small amp, efficient, clean power
Cons: this amp doesnt have a built in HD tuner (i kno that makes no sense but i had to put something in this dialogue box) :)
9 of 9 found this helpful
First off this footprint is an ideal size and that's it ! I've been wanting to try this amp for awhile to complete my Jl set setup...HU alpine iva w205, Jl zr650csi, Jl tr650 all wiring Jl..its not what I expected at all for $$$$$ period I'm putting my polk pa660 right back in it seems even at 75 rms was warmer in sound and pushed the setup beyond it needed vs the HD and the gain isn't even 3/4.
Pros: Size, size, size
Cons: Better amps out there for less $$$$ your buying the name in this case...
6 of 23 found this helpful
Acabo de recibir mi jl audio hd 600/4 y estoy un poco desepcionado, lo compre por que pense que sonaria mejor que mi alpine pdx 4.150 , pensando que el jl hd seria mejor, pero no fue asi, el hd tiene unos agudos un poco chillones , el pdx es bastante calido ,los ajustes y ganancias practicamente estan igual. sinceramente no valio la pena gastar 800 dlls cuando puedes comprar un alpine pdx 4.150, mi hu es una alpine cda-117,mis bocinas son dls iridium 6.3 3 way . Translation provided by Crutchfield's Spanish Sales & Support team. Find more information en español here: <a href="http://www.crutchfield.com/app/spanish">http://www.crutchfield.com/app/spanish</a> I just got my hd jl audio 600/4 and am a bit disappointed, I bought it because I thought it would sound better than my alpine pdx 4150, thinking the hd jl would be better but it was not so, the HD has a slightly sharp sound, the pdx is quite warm, adjustments and gains are almost equal. honestly not worth it for the price when you can buy an alpine pdx 4150, my hu is an alpine cda-117, my speakers are 3 way dls iridium 6.3
6 of 31 found this helpful
This amp is awwweeesssooommmee. It's everything I was hoping for and looking for. Gets loud, has nice midrange punch I want and so dang crisp and clear! It's great. Highly recommend it!
9 of 12 found this helpful
Fantastic amp. Plenty of power, crisp, clean and just wonderful. It's very easy to setup. The instructions provide plenty of information to setup and tweak your system. I have been waiting a long time to order this amp, finally did and I absolutely love it. Highly recommend it, it's worth the money. I have it powering 2 pairs of Polk MoMo Component speakers in my 2008.5 VW GTI. I have 4 guage powering it, and 12 guage supplying the speakers from the amp. All connected to an Alpine iDA-X305 headunit.
14 of 17 found this helpful
Not fair to compare this amp to anything else out there , nothing compares in size , sound quality and power . My only advice is, if you going to spend this much money on this amp ,don't go cheap with the speakers ,it would a crime to use this amp with the factory speakers or coaxials for that matter.
24 of 27 found this helpful
I've been a car stereo enthusiast for 3 decades, whether installing the equipment myself or getting lazy (lately) and having others doing it for me. When the salesman told me that the HD600 would have more than enough power to drive my set of 3-way components and a JL 12w3 Sub (in a Stealthbox), I was quite sceptical. Still, I thought why not try. I am amazed that this little Class D amp drives my entire system with ease. It only gets warm to the touch, is quiet and clear, and will allow my system to get as loud as my ears can handle (and body can shake due to the awesome 12w3 Sub). If you have not experienced JL equipment, you really need to. It's in a league of its own.
23 of 23 found this helpful
I bought this to replace 2 amps. I have speaker system up front with a 8" in the door, 3" Mid in the kick, and 1.1" in the dash and had a 5 channel Alpine MRV-F450 running bridged to 2 channel at 120watts pushing them before. Had a FD2200 amp pushing my JL Audio VR-650CXi's in the rear doors. Now that I have the JL HD600 in there, the system sounds so much better. The 8" in the front doors slam, the whole system is crystal after a few adjustments on the Fosgate 360.2 processor. My question to the people who are having noise issues.... did you use a volt meter to set the "Input Sensitivity"? I have no issues and no complaints. I am waiting for my HD750 to get here in 2 days for my 12W7 and I'll be a happy camper. In the 17 years I've had systems, I can honestly say that this is the BEST amp I have EVER owned, and I have had way too many to count. Small, compact, clean, and powerful. Fantastic buy everyone. You'll be happy.
18 of 18 found this helpful
i hooked this amp up to the stock head unit in my 08 honda accord coupe with NAVI. I didnt use any processors like the cleansweep. There is absolutely no noise, no turn on pop, the sound is loud, clear, and smooth. I am running a set of JL C5 splits off the front channels and a JL sub off the rear channels bridged. The clarity and volume out of such a small amp is unbelievable. I had an old RF BD1000 running my sub before this and the 300 watts from this amp are almost as loud, but much more musical than the 1000 watts from the BD1000. I couldnt be happier with this amp.
13 of 13 found this helpful
This amp is AWESOME! Small, runs cool, loud as you will ever need, and plays so wonderful. I replaced a pair of 300/2 amp with this and I have to say this amp sounds better than the other two. Clearer, cleaner, and way smaller. Worth every penny.
9 of 11 found this helpful
I purchased this amp to replace my Alpine PDX 4.150 which was too noisy. This amp is incredible. I have no noise as stated in previous review, and the sound quality is better than the Alpine PDX by far and on par with my JL slash 4x75 amp. I am powering 2 sets of Boston 6.5"s and 1 12 inch woofer. If you want to save space and want top quality sound, this is your amp. I would rate it on par with my last set that were running my components.
13 of 14 found this helpful
I purchased this this amp to power my Boston Acoustics Pro50 components and one JL 12w3 Sub. I was immediatly impressed by the amount of power for such a small amp, I couldn't believe it! I don't have any complaints with the clarity of the amp but then again I didn't have another amp to compare it to. However, the compliant I do have is the noise in the signal. It seems to be a bit loud even though its rated at 109db then again it might be my patch cables too, not sure but I'll try a different pair. Overall, I'm very happy with performance of the 600HD.
13 of 20 found this helpful
Was very excited to try amp out for my 2 sets of Infinity Kappa 6.1 Perfects.I must say I was impressed by the size and power.you can really feel the power but the clarity just wasn't there.It left me scratching my head,but I was not worried because Crutchfield has an excellent return policy.So I put my JL 450/4 back in and that alone sounded great like always.So in my conclusion for the money and clarity it did not sound cleaner than the JL 450/4 and justify me spending another $800.00 for my system.And a big thumbs up for Crutchfield,excellent service and fast shipping.
54 of 69 found this helpful