# JL Audio HD900/5 Review



## ChrisB (Jul 3, 2008)

After growing tired of dedicating 12.5” x 40” to three amplifiers over my rear axle hump, I decided that it was time to purchase a JL Audio HD900/5 and see if it would meet or exceed my expectations. I finally have the amplifier installed, and I must say that I was a little leery about giving up a little power here and there to run the 900/5. Well, now that it is in there, and tuned the way I liked it, I must say that my power deficit concerns were irrevelant. Just in case anyone wants to know, here are my system specifications: Alpine CDA-9887 source; Tang Band W4-1757SB (500 Hz on up); Mach5 Audio MLI-65 (80 to 500 Hz); Subwoofer – 13w6v2 Mustang Stealthbox (80 Hz on down).


Thus far, I have limited listening with the amplifier, but Pink Floyd - Dark Side of the Moon sounds GREAT. I also listened to a few tracks from Nine Inch Nails - The Fragile, and I was impressed. The imaging in Somewhat Damaged is spot on and the midbass in We’re In This Together is most certainly there. I also cranked up the volume on Killasound by Freestylers vs Wizard just to see if I would notice the 350 watt power deficit on my subwoofer. I must say, the theoretical 2.55 decibel loss in subwoofer output by going from 850 watts to 500 isn’t as noticeable as I thought it would be. If anything, the subwoofer appears to blend better at all volume levels versus being overpowering at times. 

Any concerns I once had about full range class D are now moot. Granted, it was hard to get past the stigma of the Alpine PDX-5 that I tried in 2008, but this amplifier literally smokes it. My complaints about the Alpine were lack of midbass, lack of subwoofer output, and noise. I am happy to report that the JL Audio HD900/5 has NONE of these issues! If you are tired of dedicating a whole bunch of real estate to multiple amplifiers and are on the fence about purchasing a 900/5, my advice is to purchase it!

Lastly, other options I considered were the Kenwood XR4s with a XR1; Alpine PDX F4 with a PDX M6; and the JL Audio 600/4 with a HD750/1. The reason the HD900/5 won out was due to the fact that I get everything in one amplifier!

Edit, here is what the 900/5 replaced:









From left to right: Lunar L60x2; Lunar L2125; Clarion DPX1851.


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## rsutton1223 (May 29, 2011)

This one was on my radar along with the Hertz HDP 5 and Alpine PDX 5. I have size constraints that make going fully active almost require one of these amps to keep the function of my car the way I want it.


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## bigdwiz (Oct 7, 2010)

I'm selling off some of my amps to pick up one of these. Thanks for the review, ChrisB! 

I'm curious to get it on my test bench to see the actual #'s....did it come with a birthsheet?

--


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## never2late (Jun 16, 2011)

Thanks, for that review. The Alpine PDX-5, Massive nx-5 and jl hd900/5 are on the short list. I take it that the apline was a let down for you. Thanks again


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## ChrisB (Jul 3, 2008)

bigdwiz said:


> I'm selling off some of my amps to pick up one of these. Thanks for the review, ChrisB!
> 
> I'm curious to get it on my test bench to see the actual #'s....did it come with a birthsheet?
> 
> --


No birthsheet. I would have benched it, but I don't have enough resistors to load all the channels down nor would my power supply like that. Every time I get a bigger amplifier, I wish I had sprung for that 75 amp Iota over the 55 amp Iota.



never2late said:


> Thanks, for that review. The Alpine PDX-5, Massive nx-5 and jl hd900/5 are on the short list. I take it that the apline was a let down for you. Thanks again


I was told that the newer PDX-5 wasn't as bad as the old ones. I heard a PDX F4 and it seemed light years ahead of the 2008 PDX-5 that I tried out for 15 minutes. My only recommendation would be for you to listen to one prior to deciding.

While stepping down from 850 to 500 watts on the sub wasn't that bad, I don't think I could go from 850 to 300


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## DS-21 (Apr 16, 2005)

Interesting it had enough power for your setup. It didn't quite for mine, at least for the midbasses. 

It's accurately rated, but I found I "needed" more than 3dBW more to get clean dynamic peaks at the (high) levels at which I normally listen in the car. (Remember, LOUD roadster.)


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## ChrisB (Jul 3, 2008)

DS-21 said:


> Interesting it had enough power for your setup. It didn't quite for mine, at least for the midbasses.
> 
> It's accurately rated, but I found I "needed" more than 3dBW more to get clean dynamic peaks at the (high) levels at which I normally listen in the car. (Remember, LOUD roadster.)


I was surprised too. I went from a 50x4 amplifier on the stage with the Clarion on the sub to 60x2 and 125x2 on the stage, then noticed that I didn't need as much gain on the sub. I left the gain the same in the Clarion from when I had the 50x4 in place, and I had to turn it down with more midbass power.

I was thinking the 900/5 wouldn't be enough for a power freak like me, and thus far, I was wrong. Now if you see me changing out for more power in a few months, feel free to say "I told you so!":laugh:


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## kvndoom (Nov 13, 2009)

Choosing between this and the Dreadnought for my next amp is going to be _extremely _difficult.


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## kvndoom (Nov 13, 2009)

kvndoom said:


> Choosing between this and the Dreadnought for my next amp is going to be _extremely _difficult.


Just read about the Zed price hike.. Guess it's not a hard choice after all! WTF?!?


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## ChrisB (Jul 3, 2008)

kvndoom said:


> Just read about the Zed price hike.. Guess it's not a hard choice after all! WTF?!?


Wow! After seeing Zed's new pricing, all of a sudden JL Audio looks like a bargain.


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## Chaos (Oct 27, 2005)

So, the full range class-D sounds OK to you?

What's your impression of the headroom with that amp?


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## rytekproject (Feb 25, 2011)

kvndoom said:


> Just read about the Zed price hike.. Guess it's not a hard choice after all! WTF?!?


Cancelled group buy due to lack of demand then a price hike? I dont see the logic here...


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## truckerfte (Jul 30, 2010)

rytekproject said:


> Cancelled group buy due to lack of demand then a price hike? I dont see the logic here...


Neither did I. And gb was pulled just before I was set to order a leviathan. I'm sure its a kick-ass amp, but ill never know. They aren't getting my money. And yes, I'm gonna say it every time the group buy/price hike comes up. 

Sent from my SPH-D700 using Tapatalk


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## ChrisB (Jul 3, 2008)

Chaos said:


> So, the full range class-D sounds OK to you?


It sure does. Hard to believe it since I was once an old school die hard who was once stuck in my ways. My only advice is to open your mind and take what certain individuals who preach class ab as the only way to do car audio with a grain of salt. Either that or run down to your local JL Audio dealer and demand a demo between this amplifier and a class ab amplifier on their sound board. As a word of caution, watch out for their dirty trick where they will gain one amplifier higher than another. Differences in output levels are way easier to pick out than actual sonic differences between two amplifiers that measure similarly! Then again, knowing me, I'd be the person who walks into a stereo shop with my Fluke DMM and a test tone CD prior to demanding a demo. You want my money? Well, you are going to have to earn it!

I also performed the most critical experiment of them all by making my wife listen to my setup from the driver's seat. The only thing she complained about was that I didn't have any mids and highs in the back. I'll never understand why she always fades her system to where more music is coming from BEHIND her head than up front.



Chaos said:


> What's your impression of the headroom with that amp?


The headroom is fine thus far. I was skeptical since I was giving up a little power here and there, but my skepticism seems unwarranted thus far.


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## Chaos (Oct 27, 2005)

ChrisB said:


> It sure does. Hard to believe it since I was once an old school die hard who was once stuck in my ways. My only advice is to open your mind and take what certain individuals who preach class ab as the only way to do car audio with a grain of salt. Either that or run down to your local JL Audio dealer and demand a demo between this amplifier and a class ab amplifier on their sound board. As a word of caution, watch out for their dirty trick where they will gain one amplifier higher than another. Differences in output levels are way easier to pick out than actual sonic differences between two amplifiers that measure similarly! Then again, knowing me, I'd be the person who walks into a stereo shop with my Fluke DMM and a test tone CD prior to demanding a demo. You want my money? Well, you are going to have to earn it!
> 
> I also performed the most critical experiment of them all by making my wife listen to my setup from the driver's seat. The only thing she complained about was that I didn't have any mids and highs in the back. I'll never understand why she always fades her system to where more music is coming from BEHIND her head than up front.
> 
> ...


LOL. I actually run a 5-channel class D already; if I worked for a JL dealer, it would probably be a 900/5. 

As it is, A/B has it's place, but I've converted from the camp which maintains that class-D isn't capable of full range.

Honestly, I wouldn't mind if somebody did come into the shop with a DMM and knew how to use it. I'd like it a lot more if that sort of thing happened more often (or ever).


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## subwoofery (Nov 9, 2008)

kvndoom said:


> Just read about the Zed price hike.. Guess it's not a hard choice after all! WTF?!?


A lot of people have been complaining that there is less and less US made companies in the industry. Zed is still "Proudly Made in USA" - but when people see the MSRP, they freak out and think: "Made in asia? Can't be that bad of an amp" 

Don't understand you guyz... (FYI, I'm not American )

Kelvin


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## ChrisB (Jul 3, 2008)

subwoofery said:


> A lot of people have been complaining that there is less and less US made companies in the industry. Zed is still "Proudly Made in USA" - but when people see the MSRP, they freak out and think: "Made in asia? Can't be that bad of an amp"
> 
> Don't understand you guyz... (FYI, I'm not American )
> 
> Kelvin


Ahh, but here is the conundrum. Are his amplifiers really "Made in USA" or are they "Assembled in USA"? The FTC has strict guidelines regarding the use of American Parts and whatnot and I would almost believe that a circuit board mostly assembled in Korea that is slapped into a heat sink here in the USA does NOT count as "Made in USA" under the FTC's guidelines.

For further reference: "Made in U.S.A". Standard

From Page 5 of **THIS** document:
*What is the standard for a product to be called Made in
USA without qualification?*

For a product to be called Made in USA, or claimed to be of
domestic origin without qualifications or limits on the claim,
the product must be “all or virtually all” made in the U.S.
The term “United States,” as referred to in the Enforcement
Policy Statement, includes the 50 states, the District of Columbia,
and the U.S. territories and possessions.


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## dodgeman70592 (Jun 16, 2009)

Couldn't have said it better, that's why I'm running two of them. Love those amps.


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## fish (Jun 30, 2007)

Chris, have you experienced the 900/5 getting really warm? I've got a pair of the 600/4's & they do tend to get pretty hot. Having them stacked & it being over 100* probably doesn't help either.


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## kvndoom (Nov 13, 2009)

subwoofery said:


> A lot of people have been complaining that there is less and less US made companies in the industry. Zed is still "Proudly Made in USA" - but when people see the MSRP, they freak out and think: "Made in asia? Can't be that bad of an amp"
> 
> Don't understand you guyz... (FYI, I'm not American )
> 
> Kelvin


Erm, I'm not one of those people.


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## ChrisB (Jul 3, 2008)

fish said:


> Chris, have you experienced the 900/5 getting really warm? I've got a pair of the 600/4's & they do tend to get pretty hot. Having them stacked & it being over 100* probably doesn't help either.


Thus far it hasn't been running anything other than warm. I'll be keeping an eye on it because I want to use non backed carpet to cover my rear deck mount.

Edit: I beat up on it pretty bad for about 30 minutes straight about an hour ago, and again, it was merely warm to the touch.


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## subwoofery (Nov 9, 2008)

kvndoom said:


> Erm, I'm not one of those people.


I just quoted your post but wasn't pointing you out  Just wanted to make a point 

Kelvin


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## onelivinlarge (Apr 10, 2011)

i mite have to look in to this now because i to am tired of having to dedicate that much space to my amps and my zapco ref 500.1 is tiny but my mq quart a/b class not so much


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## ChrisB (Jul 3, 2008)

Well, I decided to break out the RTA on the new versus old setup. 

The old setup was 50x4 and 850x1:









Sorry but I didn't RTA the 60x2; 125x2; and 850x1 as it was temporary. 

Here it is with the HD900/5:









Here is new versus old as best as I could line it up:









All in all it makes sense due to the fact that there are power differences between the new and old setup.


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## FartinInTheTub (May 25, 2010)

I was on the fence when it came to the 900/5. I have a 2 year old and need to get his toys and stroller in the trunk. My 3 Soundstream amps, although amazing... take up a lot of real estate. I just picked up a 900/5 and am waiting to to get it in the mail. I can't wait to take back some space in my trunk! I'll be running Focal K2ps in the front and some Morel coaxials in the back. The sub channel will be powering a single IDQ10v3. Can't wait! Your review solidified it for me! thanks for taking the time to write it. I plan on installing it next to my battery under the spare tire cover... I've seen it installed there many times with no heat issues to speak of. Anyhow, Thanks again! I'll post my opinion when I get the baby installed! Woot Woot!


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## fish (Jun 30, 2007)

ChrisB said:


> Thus far it hasn't been running anything other than warm. I'll be keeping an eye on it because I want to use non backed carpet to cover my rear deck mount.
> 
> Edit: I beat up on it pretty bad for about 30 minutes straight about an hour ago, and again, it was merely warm to the touch.



That's good news! Maybe I should unstack mine. 

The RTA readings make sense, since you lost power on the sub & doubled power (theoretically) on the midbass & widebander.


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## CGMMNY (Jul 26, 2011)

fish said:


> Chris, have you experienced the 900/5 getting really warm? I've got a pair of the 600/4's & they do tend to get pretty hot. Having them stacked & it being over 100* probably doesn't help either.


I have one and it does get hot. However it's never cur off. I'm actually pulling it and going with a multi-amp setup again.


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## msmith (Nov 27, 2007)

Thanks for the great writeup... glad you like the HD900/5

If you want more headroom all around, you can always get a second HD900/5 and run one for left and the other for the right channel, with each subwoofer channel running its own sub. I've heard a couple of systems running this setup and it is pretty spectacular: 150W x 4 at 4 ohms (bridged) + 500W x 2 for subs... and it is still a very compact setup.

Manville Smith
JL Audio, Inc.


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## FartinInTheTub (May 25, 2010)

msmith said:


> Thanks for the great writeup... glad you like the HD900/5
> 
> If you want more headroom all around, you can always get a second HD900/5 and run one for left and the other for the right channel, with each subwoofer channel running its own sub. I've heard a couple of systems running this setup and it is pretty spectacular: 150W x 4 at 4 ohms (bridged) + 500W x 2 for subs... and it is still a very compact setup.
> 
> ...



While that seems like a nice setup it hardly seems cost effective for most people. I feel that the true selling point of the 900/5 is the ability to run one very small amp and still have sufficient power and sonics to satisfy most listeners. I just purchased a 900/5 for those reasons only.... Can't imagine someone spending a couple grand on two of these and using them in that configuration. For 2 grand one could get more for the money imo.


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## ErinH (Feb 14, 2007)

I've had my 3 hd amps under the front seats for about a year now and still have no complaints. going on about 2.5 years of ownership. great amps.


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## fish (Jun 30, 2007)

msmith said:


> Thanks for the great writeup... glad you like the HD900/5
> 
> If you want more headroom all around, you can always get a second HD900/5 and run one for left and the other for the right channel, with each subwoofer channel running its own sub. I've heard a couple of systems running this setup and it is pretty spectacular: 150W x 4 at 4 ohms (bridged) + 500W x 2 for subs... and it is still a very compact setup.
> 
> ...


Manville,

Will a 900/5 do 150X2 bridged at 8 ohms also?


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## ChrisB (Jul 3, 2008)

According to the manual it is 200w RMS x 2 at 8 ohms bridged! Makes sense since each channel theoretically sees a 4 ohm load in an 8 ohm bridged situation.


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## subwoofery (Nov 9, 2008)

fish said:


> Manville,
> 
> Will a 900/5 do 150X2 bridged at 8 ohms also?


If it does 100 @ 4 ohm then it will do 200 @ 8 ohm bridged... 

Kelvin


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## fish (Jun 30, 2007)

"When bridged, each
main channel pair will optimize output at
150-200 watts between 3 – 8Ω."

This, which was in the manual, is why I asked. I hadn't taken a look at it in a while, & couldn't remember exactly what it said. I've noticed that JL's amps (all lines) seem to have more output in general @ 8 ohms than other brands. This, of course, a good thing.


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## VaVroom1 (Dec 2, 2005)

subwoofery said:


> A lot of people have been complaining that there is less and less US made companies in the industry. Zed is still "Proudly Made in USA" - but when people see the MSRP, they freak out and think: "Made in asia? Can't be that bad of an amp"
> 
> Don't understand you guyz... (FYI, I'm not American )
> 
> Kelvin


Putting it in perspective, the sequence of events really puts me off. I WAS ready to put my money in a leviathan and a dreadnaught when the gb was pulled. Then the price increase by $200 each!??
It would have been an entirely different story if it started off at this new price.

Go figure.


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## truckerfte (Jul 30, 2010)

VaVroom1 said:


> Putting it in perspective, the sequence of events really puts me off. I WAS ready to put my money in a leviathan and a dreadnaught when the gb was pulled. Then the price increase by $200 each!??
> It would have been an entirely different story if it started off at this new price.
> 
> Go figure.


Hmm...and I thought I was the only one who got pissed about the whole deal

Sent from my SPH-D700 using Tapatalk


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## FartinInTheTub (May 25, 2010)

Installed my 900/5 yesterday! tucked it away in the stock changer location in my Bimmer. I like the fact that I can simply shut the changer door and you'd never know it's there. tucked the K2p crossovers in there as well.


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## 9mmmac (Dec 14, 2010)

Schwing! So... After having a lot of other GOOD stuff in your car, whaddya think of it's SQ? Punchy and dynamic? Any particular "flavor" it imparts to the sound? How did the tuning go?


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## FartinInTheTub (May 25, 2010)

9mmmac said:


> Schwing! So... After having a lot of other GOOD stuff in your car, whaddya think of it's SQ? Punchy and dynamic? Any particular "flavor" it imparts to the sound? How did the tuning go?


I would say it sounds good! pretty punchy and dynamic. Haven't worked with my EQ yet... Ive only set the gains. I have to say that this isn't your average Class D. I'm actually VERY impressed at this point. My frontstage is 4ohm so I'm getting the full 100 watts. The 500 watts to my SI BM MKIII is very sufficient! The thing blends very well. I look forward to tuning even though I suck at it. I sure wish I had an RTA!


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## Syaoran (Jun 27, 2011)

FartinInTheTub said:


> While that seems like a nice setup it hardly seems cost effective for most people. I feel that the true selling point of the 900/5 is the ability to run one very small amp and still have sufficient power and sonics to satisfy most listeners. I just purchased a 900/5 for those reasons only.... Can't imagine someone spending a couple grand on two of these and using them in that configuration. For 2 grand one could get more for the money imo.


Not to cause any fanboy problems or anything, but this sounds awfully like a PDX-F6 + M12 setup.... lol.


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## kvndoom (Nov 13, 2009)

Syaoran said:


> Not to cause any fanboy problems or anything, but this sounds awfully like a PDX-F6 + M12 setup.... lol.


It will be interesting next year when I can compare the F4/M6 duo against the 900/5 in my car. Come on, tax time! :laugh:


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## 11blueGTI (Apr 24, 2011)

Glad to see another convert. I have used the HD 600/4s in the past and will use them in my new install.


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## Syaoran (Jun 27, 2011)

kvndoom said:


> It will be interesting next year when I can compare the F4/M6 duo against the 900/5 in my car. Come on, tax time! :laugh:


Hopefully by next year alpine will released a revamped PDX-5, to fight the HD900/5.

The V60 and XD700/5 seem to be good contenders, so it's to be expected top of the line vs top of the line.


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## jp_over (Dec 21, 2011)

Good read - I've been in an internal debate on whether to get the HD now or wait on the new PDX V9. Ah, decisions!


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## jeepguy_1980 (Dec 3, 2011)

I just ordered an HD900/5 myself.

I'm looking at amp install kits and trying to decide if I need 4ga or 2ga wiring. The manual says 4ga minimum. But looking at JL branded amp install kits, a 4ga kit is rated for 800amps.

My amp will be right next to my battery, and will probably use less than 5ft of wire.


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## subwoofery (Nov 9, 2008)

jeepguy_1980 said:


> I just ordered an HD900/5 myself.
> 
> I'm looking at amp install kits and trying to decide if I need 4ga or 2ga wiring. The manual says 4ga minimum. But looking at JL branded amp install kits, a 4ga kit is rated for 800amps.
> 
> My amp will be right next to my battery, and will probably use less than 5ft of wire.


More like 100amps... I don't see a 4AWG cable handling 800amps 
Unless you meant watts ; which sounds right in the ballpark 

Kelvin


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## jeepguy_1980 (Dec 3, 2011)

subwoofery said:


> More like 100amps... I don't see a 4AWG cable handling 800amps
> Unless you meant watts ; which sounds right in the ballpark
> 
> Kelvin


You are absolutely correct. I did not mean amps and can't believe I even wrote that.

So do you recommend a 4AWG kit?


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## subwoofery (Nov 9, 2008)

jeepguy_1980 said:


> You are absolutely correct. I did not mean amps and can't believe I even wrote that.
> 
> So do you recommend a 4AWG kit?












Kelvin


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## quality_sound (Dec 25, 2005)

I asked Manville and he specifically said, 4ga for one HD and a 2ga main with 4ga feeders for 2 or 3 HDs. If it's just the one, a single 4ga is fine.


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## rain27 (Jan 15, 2009)

Curious where you guys have your gains set with the sub channel on the 900/5.

To get around the same output as the 750/1 I used, I had to turn the gain to about 2 o'clock. Gain was at about 10 o'clock on the 750/1.


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## quality_sound (Dec 25, 2005)

Of course you have to turn it up more, it has 33% less power than the 750/1.


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## rain27 (Jan 15, 2009)

quality_sound said:


> Of course you have to turn it up more, it has 33% less power than the 750/1.


Doubling of power is only a 3db increase. The difference I have experienced is more substantial, and that's with only a 50% increase in power.

And this is with a sub rated at only 400 watts to begin with.


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## fuji6 (Feb 4, 2008)

msmith said:


> Thanks for the great writeup... glad you like the HD900/5
> 
> If you want more headroom all around, you can always get a second HD900/5 and run one for left and the other for the right channel, with each subwoofer channel running its own sub. I've heard a couple of systems running this setup and it is pretty spectacular: 150W x 4 at 4 ohms (bridged) + 500W x 2 for subs... and it is still a very compact setup.
> 
> ...


Any chance of strapping the sub channels? I'm thinking of getting another hd amp, because I need more channels ( running 2way active and want to add rears and a center). Debating going hd600/4 or hd900/5. Sub box is fiberglass shared space ported and my other sub option is a single sub.


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## KSpan (Mar 9, 2012)

Looking to go with a 5-channel and the XD and HD lines are both strong contenders. Any thoughts on the subsonic filter on the HD900? I'll be running a single 12 in a sealed box and like my low end tight, but have had a 20 Hz subsonic for a looong time and am a bit wary about doing without.


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## quality_sound (Dec 25, 2005)

A subsonic filter is beyond pointless in a sealed enclosure that's not excessively large.


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## KSpan (Mar 9, 2012)

quality_sound said:


> A subsonic filter is beyond pointless in a sealed enclosure that's not excessively large.


That's what I've always heard and read, but I was crossing mine at 25 Hz or so and could hear the difference (or at least believed I could). Logic tells me it shouldn't matter, but predisposition tells me otherwise, a seemingly common struggle on the car audio world


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## quality_sound (Dec 25, 2005)

It'll focus the power in a better passband so it might be a bit louder, but it won't protect the sub.


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## metanium (Feb 2, 2007)

quality_sound said:


> It'll focus the power in a better passband so it might be a bit louder, but it won't protect the sub.


Great point. I always use a subsonic whether I'm running ported or sealed. I just like the idea of not "wasting" power below what my subs can effectively produce.


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## KyleMDunn (Jan 27, 2009)

KSpan said:


> Looking to go with a 5-channel and the XD and HD lines are both strong contenders. Any thoughts on the subsonic filter on the HD900? I'll be running a single 12 in a sealed box and like my low end tight, but have had a 20 Hz subsonic for a looong time and am a bit wary about doing without.


What single 12 are you looking to run? I have had my HD900/5 for well over a year now - powering an SI BM and then an FiQ12. It has been great for both sealed applications. I would highly recommend this amp to anyone looking to have a single solution in a compact size.


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## KSpan (Mar 9, 2012)

quality_sound said:


> It'll focus the power in a better passband so it might be a bit louder, but it won't protect the sub.


Exactly - that has always been my goal.



KyleMDunn said:


> What single 12 are you looking to run? I have had my HD900/5 for well over a year now - powering an SI BM and then an FiQ12. It has been great for both sealed applications. I would highly recommend this amp to anyone looking to have a single solution in a compact size.


It's an MTX Thunder 5500 that I've been running in a 1 c.f. or so sealed box for the last 10 years or so, and before that I ran a Treo 12 in a similar box.


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## gallman (Oct 14, 2012)

Does anyone have any feelings on the JL HD line as to if the music sounds lifeless and sharp or if it sounds alive and robust. Would be very interested to hear real life listening experiences before I plunk down my cash on either the jl600/4, 900.5 or decide to go with the Alpine equivalents (using that term loosely).

Thanks.


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## quality_sound (Dec 25, 2005)

I have a 900/5 and an 600/4 and they're anything but lifeless. I was running them to old school MB Quart QSD210s (4"&tweeter) and a QSD-164 (6.5" add-on midbass) with varying subs and it was great. Tweets and mids got 100 Watts each (900/5 main channels), midbasses got 300 each from the 600/4 bridged and the sub got 500. New setup will be the 900/5 in 3-channel mode to the tweeters (150 each) and sub (500) and the 600/4 bridged to the midbasses (300 each), unless they don't fit. I have zero concerns a out if it will sound good.


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