I have been reading reviews and posts on the jh hd amps since they came out but i never actually got to listen to one until a few weeks back when i picked up a 600/4 & 750/1 in a deal with another car audio freak
After reading all the rave reviews i must say i was looking forward to listening to them ......
So far i have focused my time on the the 600/4 ,apart from hooking the 750/1 up just to test it was working OK i haven't spent any real time listen and comparing it to other amps yet ..... ..
I wont bore you all with the usual stuff about how tiny it is and how powerful and efficient it is ,what features it has ,bla bla bla .....
This is only based on how it sounds in my opinion and nothing else ..
On jl audio website it says quote "We invite you to sonically compare the HD amplifiers to any amplifier, at any price... We think you will quickly discover that all the old amplifier compromises have suddenly vanished."
Well that's just what i did ! ..
I have a number of amps i want to compare it to .
Tru 7.4t copper sweetest amp on midrange and treble i have ever listened to.
Mcintosh mc4000m (the daddy mac).
Genesis class A's , sa30 ,sa50 & da110.
Kenwood kac1023 , my favorite sub bass amp .
I started out with the amps i have hooked up on my bench at the moment .
Sony xm-2000r ,Sony's huge flagship amp
Denon dca800 , 6x50w amp from the early 90's
JL
Sony
Denon
I have used the same brand rca phono leads between amp's ,headunit and switching box except when i had to use extra rca Y leads i on the Denon to bridge it to 2 channel ..
I also use the same speakercable between amps and 2 matching pairs of speakers , Mordon Short ms10i (pearl edition). i regularly swapped round speakers to help eliminate any different sound characteristics between them
MS 10 i's
A simple switching box was used switch between amp's from the headunit. again regularly swapping outputs to help eliminate any difference on them.
switch box .
Everything was powered from the same source . and powered up all together to avoid one amp been colder than the other ..
A Vibe 50amp regulated power supply and 2 huge 12v batteries .
when i first hooked up the 600/4 i spent a full evening comparing the front channels to the rear channels to see if i could differentiate anything between them . i set/matched the front and rear gains with a spl app on my phone ,swapped rca leads,speakers ,inputs.outputs more times than i can recall . and as far as my ears could tell they are identical.
Each amp's cross overs have be turned off and set flat without any eq ,bass boost etc .. most listening was in simple 2 channel full range stereo .
ie 2 of the jl's 4 channels used, 2 of the denon's 6 channels used and the sony is a 2 channel . i often swapped round channels on the jl & denon. sometimes using the front and some times using the rears ..i also bridged the jl down to 2 channel and the denon to compare them , some time was spent running the jl & denon with a sub as well as the ms 10i's .
i used a pair of cdt es06+ subs (see pic's ,below the ms10i's) and a Aliante 12 ltd .. this wasn't a fair comparison as i would need another pair of the 06+'s in matching enclosures and another 12ltd to square things up ....
12 LTD
The head-unit i used is a Rockford 8140 set flat and with out any other processing .
I would of liked to compare the 3 amps together. i do have a third pair of MS10 speakers but they have slightly different tweeters fitted to them so that was out ,and having 2 sets of speakers abreast cause enough problems with differences width and path length distance ,imaging and staging ,stacking one set on the other set also changes things up a hole heap . i was forever swapping inner ,outer ,top ,bottom speakers around to the point i hardly knew what amp was driving what speaker set .
3 set's would of been unworkable and a total nightmare to judge fairly ..
i must of spent at least a minimum of 30 hours sitting down seriously listening to these amp's over the last 4 weeks and around the same amount of time again spent working on a motorcycle i am rebuilding and making bio-diesel in my garage all the while with some of the amps playing ..
A run down on how i compared/listened to them . after i set / leveled all the amps gains as close as i could match them with the spl app it soon became apparent the best speaker placement (sweet spot from my stool)was the outer /wider set on the lower level .
so i would change around speakers so that the amp playing would have its speakers in the that placement most of the time .
usually i would only listen to 2 amps in one day , ie the jl v the denon , the jl v the sony and some times the sony v the denon just to get a reference between them .. and it was also easier to manage the swapping over of cables ,speakers etc with 2 amps at a time ...
To warn up the amps i would connect the front outputs from the rockford to one amp and the rears outputs to the other and let them both play a few tracks together , after i would connect the switch box back to the front outputs of the rockford and both amps , set the volume depending on my mood and the music i was playing and play at least 3 or 4 tracks from a cd before switching amps on the box and swapping speaker leads over and play the same tracks again at the same volume on the head unit .. sometimes i would repeat this over and over a different volume levels while making notes .... you wouldn't believe how much i hate some of my Cd's now that i loved before :-( ...
occasionally i would play a whole CD before switching over amps and playing it again at the same volume , this is much harder than you might imagine as you can so easily get carried away in the music and stop taking notes and even crank up the volume half way through a track or CD or even forget what amp you was last listening to !
more than once i fell asleep and i also got lots of practice on my air guitar and air drums :-) ........
Now to be brutally honest i believe i made up mind as to how each amp sounded to me within the first half hour or so of listening to them ... maybe even less time than that ....
i did persevere with the comparison ,swapping round every cable, speaker, sitting position ,rca, resetting gain levels higher and lower on the amps , i used other speakers kef's ,jpw's ,Anthony Gallo .regardless what i factor i changed my overall opinion was the same ?
i have had some friends listen with me ,one who described the sound of the JL HD 600/4 exactly the same as i thought within a few minutes of listening to it ? he actually came to the same conclusions as i had as well !
later i will give a list of the cd's and tracks i used and also the conclusions i came to ,my opinion of the amp ,its strengths ,its weaknesses ...
i have one more "ace in the hole" "trick up my sleeve" so too speak .....
Sounds like you have a fun test going on here. Very interested in how you like the amp compared to this group:
Quote:
Tru 7.4t copper sweetest amp on midrange and treble i have ever listened to.
Mcintosh mc4000m (the daddy mac).
Genesis class A's , sa30 ,sa50 & da110.
Kenwood kac1023 , my favorite sub bass amp
This is what DIY is all about...gathering gear and listening!
2011 MINI Cooper S :: [build log] :: [new CarPC project]
HAT L6SE, L3SE, L1 Pro R2. 4x Alpine SWR-843D, 2x JL XD700/5, 2x XD500/3, Alpine H800, RUXC800, Mac Mini CarPC
i am holding off posting my initial findings for a little while as i want to do some further comparisons with other MODERN class D amps ....
i have very little experience with class d car audio amps ,other that some brief listening to some old infinity 275's (10 years ago) and more recently (2 years ago) jbl gto 755.6 and a 10 minute listen to a ucs pro amp & vibe sick ?? a few weeks ago. NONE them inspired me with "class d" technology ...
finding people with modern class d's around where i live is proving hard but i did come across a young friend who owns a interesting little " D "amp , not exactly a car amp but it will run from voltage between 10volts and 30 volts and he intends to install it in his car pc setup with a 2x8 mini dsp .. for want of finding any other D's i asked him to bring it over for some fun ...
today he did so .. a very quick wire up and off we go ...
shocking ,disbelief and unbelievable are words that come to mind ...
as i said it was a quick wire up ,i just used the wire i had to hand , 16awg for power something like 20awg for speakercable ...
tomorrow i will upgrade/beef up the power to 3 runs each neg and pos 10awg cable as it has 3 inputs for each .
i will also use the same speaker cable that's connected to the HD ,
maybe i might be able to work in a speaker selector switch box in reverse so i can use just one set of speakers ...have to see if that's possible...
links for the little amp if anyone is interested ..
i am holding off posting my initial findings for a little while as i want to do some further comparisons with other MODERN class D amps ....
i have very little experience with class d car audio amps ,other that some brief listening to some old infinity 275's (10 years ago) and more recently (2 years ago) jbl gto 755.6 and a 10 minute listen to a ucs pro amp & vibe sick ?? a few weeks ago. NONE them inspired me with "class d" technology ...
finding people with modern class d's around where i live is proving hard but i did come across a young friend who owns a interesting little " D "amp , not exactly a car amp but it will run from voltage between 10volts and 30 volts and he intends to install it in his car pc setup with a 2x8 mini dsp .. for want of finding any other D's i asked him to bring it over for some fun ...
today he did so .. a very quick wire up and off we go ...
shocking ,disbelief and unbelievable are words that come to mind ...
as i said it was a quick wire up ,i just used the wire i had to hand , 16awg for power something like 20awg for speakercable ...
tomorrow i will upgrade/beef up the power to 3 runs each neg and pos 10awg cable as it has 3 inputs for each .
i will also use the same speaker cable that's connected to the HD ,
maybe i might be able to work in a speaker selector switch box in reverse so i can use just one set of speakers ...have to see if that's possible...
links for the little amp if anyone is interested ..
Looks like the Sure Class D amp modules. You can source that particular one and others, along with matching power supplies, from Parts Express, e.g. see 4x100W @ 4 ohm TK2050 Class-D Audio amplifier Board 320-302. Note that the "100W" rating is likely at "<10%THD". I don't think they have a power supply suitable for car audio use however. I don't believe you will not get its full potential running it direct from a car's 12V supply. And then there's the remote turn-on requirement to consider...
I used the following CD’s in my listening sessions
Focal demo disc’s 1,3,4,5&6
Alpine Reference Disc
Dynaudio feeling music CD
These are my favorite “SQ Reference” CD’s , there is some fantastic tracks for evaluating purposes not only can they give your setup a good workout they have a huge range of musical styles and great music .
I played various tracks from these CD’s
Fleetwood Mac - The Dance
Sultans of Swing - Best of Dire Straits
John Mellencamp 1978-2005 A Biography
Steve Earle - The collection
Michael Jackson - Thriller
Shania Twain - Come On Over
Wynonna Judd - Revelations
Katherine Jenkins - Believe
AC/DC -Back in Black & Let There Be Rock
Def Leppard - Adrenalize & Hysteria
Michael Buble - Crazy Love
Guns n Roses - Appetite for destruction
John Holt - 1000 Volts
Gregory Isaacs -Night Nurse
Dr Dre - The Chronic 2001
Bob Marley - Legend
Relax - 1980’s 2cd
Beegees - greatest hits
Maybe a few others i can’t recall right now ....
I know i said i would do some further testing but it’s got to the point today that i am just going round in circles , and more testing is just confirming what i already know !..............
I WANT TO MAKE A FEW POINTS FIRST...
1. As i said earlier I bought these JL HD AMPS , well actually I done a deal with 2 of my amps and cash to the other guy .. When it’s all said and done I paid out a big lump of my hard earned money of these amps one way or the other...
2. i am a JL Audio fan , in so much as i rate there subs..and have a number of them over the years , I know for a fact I owned the very first 15w6 in theUK many years ago ...so have no hidden agenda or axe to grind with JL audio ..
3. my testing is far from ideal , not in any way scientific at all , and not in the intended environment that the amp was designed for “inside a automobile “ just me and my ears and my heart.
4. The amp played and functioned 100%, exhibited no signs of stress or showed any indication that it was in need of any repair at any time over the weeks of use ....
5. it’s just my opinions and thoughts, i am not out to upset anyone or start arguments so no flaming please guys...
Let’s get onto it , you have seen i have listened to the amp seated in a central position without any form of digital or analogue processing ,no eq ,no ta ,no cross over’s . Just a head-unit the amp and a pair of speaker ...I also have direct comparisons (amps) that with the flick of a switch I can compare to >
If on the other hand if I was testing the amp in isolation in car without the luxury of other amps to make direct comparisons to ,off centre seating and maybe using processing ,ta ,eq , x-o ect ect . Would the outcome be different? You will have to decide that for yourselves!
THOUGHTS
If music is food for the soul , feasting on the hd600/4 left me hungry ,tired and cold ....
Its ability it take a great recording and suck the life and emotion from it is disturbing.
Presents music like a young unemployed actor reading Macbeth for the first time at a screen test for the RSC, word for word correct but lacks the skill and experience .
Each and every detail and instrument can be followed note for note throughout the track but it stumblingly refuses to combine the instruments and vocals together to form “ music” ,rather like listening to individual parts that never gelled and felt out of time and disjointed .Harmony vocals are pulled apart and that’s just wrong !
Stereo sound stage is also “different” ! it has a very strong and focused left, right & centre but poor integration across the stage and actually draws you attention to the directly to the speakers ,
Width was only as wide as the speakers while depth suffered from a awful trait this amp has of projecting the centre information several feet further way than the left or right .( in the Michael Jackson track where the footsteps walk across from right to left ,on the hd they walk in a arc away From you from right to left ).
Like your boss at the company Christmas party , it never lets go and gets down and dirty ..Always in total control at the expense of sounding compressed & restrictive , heck its anal !
The longer i listened to it the more fatigued i felt ,left me feeling flat and tired no matter what music was played ,it just never got into the groove and hit that spot ....
I could go on and on but i think you get the picture .. in all i am very disappointed in the amp
I respect what you feel/found but I disagree. I think the amps work just as they should. In fact, I'd almost question what the other amps you're listening to might be doing to the signal throughput but that's another day.
I'm not going to burn you at the stake. I'll just disagree and leave this with saying that the top 2 scorers at MECA finals this year run only JL HD amps. And if competition isn't your thing, I encourage others who are following your post as gospel (trust me, it will be taken as such by many) to listen to a properly integrated system using Class D amps. The only issues I've found with common day Class D is that the SNR is a bit higher in earlier models (notably, alpine's 1st gen PDX line). Otherwise, given the benefits, and no side effects that I've been able to measure or hear for that matter, I'll still stand by Class D.
I've been running 2 hd600/4's and a single 750/1 for nearly 3 years now. Ask anyone who knows me and they'll tell you that it's either a testament to my belief in their ability to do what they need to... or I'm just lying about not having swaped them out.
Thanks for taking the time to do the writeup in the manner you did. I wish more folks were as methodical as you are. You've put the OG's here to shame.
I appreciate you've taken time to note that it's simply an objective opinion. The fact is, to truly A/B something, the steps required are much greater than many of us can achieve. Vance Dickason wrote on this specifically and Floyd Toole discusses it when discussing the importance of subjective testing; our hearing memory isn't what we think it is and psychoacoustics have been proven to take effect. At the end of the day, however, you have to purchase what you like and you've done a great job of exploring your options and coming to a conclusion on what you should run.
Great work.
- Erin
Yuri, I mentioned above about Floyd Toole's efforts regarding testing. Here's a GREAT article to read which really stresses how much psychoacoustics plays in to what you hear and how to really have a good test, it needs to be as "blind" as possible and the way to achieve this isn't as simple as putting on a blindfold. I should have posted this before, but I didn't see your thread until now. http://www.pocket-lint.com/news/3409...dardised-sound
I encourage anyone else who wants to themselves and their own testing true justice to read the same. This isn't me harping. This is me trying to help the community learn that proper testing is the only way to test.
I respect what you feel/found but I disagree. I think the amps work just as they should. In fact, I'd almost question what the other amps you're listening to might be doing to the signal throughput but that's another day.
I'm not going to burn you at the stake. I'll just disagree and leave this with saying that the top 2 scorers at MECA finals this year run only JL HD amps. And if competition isn't your thing, I encourage others who are following your post as gospel (trust me, it will be taken as such by many) to listen to a properly integrated system using Class D amps. The only issues I've found with common day Class D is that the SNR is a bit higher in earlier models (notably, alpine's 1st gen PDX line). Otherwise, given the benefits, and no side effects that I've been able to measure or hear for that matter, I'll still stand by Class D.
I've been running 2 hd600/4's and a single 750/1 for nearly 3 years now. Ask anyone who knows me and they'll tell you that it's either a testament to my belief in their ability to do what they need to... or I'm just lying about not having swaped them out.
Thanks for taking the time to do the writeup in the manner you did. I wish more folks were as methodical as you are. You've put the OG's here to shame.
I appreciate you've taken time to note that it's simply an objective opinion. The fact is, to truly A/B something, the steps required are much greater than many of us can achieve. Vance Dickason wrote on this specifically and Floyd Toole discusses it when discussing the importance of subjective testing; our hearing memory isn't what we think it is and psychoacoustics have been proven to take effect. At the end of the day, however, you have to purchase what you like and you've done a great job of exploring your options and coming to a conclusion on what you should run.
Great work.
Always in total control at the expense of sounding compressed & restrictive
I somewhat agree with Yuri on this. My time with the JL HD's reminded me of listening to my pc. And for the record, my pc audio side is HT Omega Calro halo XT, Simplifi Digital 7075 & Definitive Technology BP10
^^^ Please translate this into English since I have no clue if this is good or sucky lol.
Well........................ the pc bits are there to inform that we are not talking about the mobo onboard sound. As for the HD amp, I am not saying it sounded bad. To me it sounded compressed! Look at it this way, I had the Arc Audio XXK series prior. It was a step backwards SQ wise replacing them with the HD's. The HD's are now replaced by the Tru's in my sig. This move is a step forward back up the SQ ladder. However, the 500 watts from the HD900 makes the 600 watts from the SB6 channel 5&6 bridge sounds/feels like 200watts.
I see said the blind man, I found that with my 600/4 I had more of a completed sound system. Overall with that and my HD750/1, I was very happy with the output. Now I am far from an expert, but for my needs it was the perfect fit. Sorry for my rambling, carry on.
JL HD600/4 ... My Thoughts
Press here
Linear Mode
