Failing JBL PRX635's

[nchangin]

Originally Posted by duck995

My first two were early on in production, and it may be that they had problems that have been corrected on the production line since - and as mine are serviced the problem is taken care of. (note to self - ask JBL tech support if you call them back!)

I'd have to ask myself if a company invests more in defending class action lawsuits and/or service costs and/or loss of reputation on the "brand" vs. investing more in R & D for any given faulty product that is released.

[Zeromus-X]

ChiroVette, is there anyone near you who runs a PRX system that you could hire for the night? (Likewise with the QSC system.) You seem to have a lot of hesitation regarding directionality, sound, etc, etc... and it seems like paying a soundguy to come out to make sure your $10,000+ investment is well spent would be good money.

[ChiroVette]

Originally Posted by nchangin

I'd have to ask myself if a company invests more in defending class action lawsuits and/or service costs and/or loss of reputation on the "brand" vs. investing more in R & D for any given faulty product that is released.

Is this an accurate statement that can be backed up with facts or is this just your opinion? Not criticizing, just asking if you are expressing opinion or fact here since I am looking at JBL cabs as a possible purchase.

Originally Posted by duck995

JBL's explanation about failure rate of 635's helps some. My first two were early on in production, and it may be that they had problems that have been corrected on the production line since - and as mine are serviced the problem is taken care of. (note to self - ask JBL tech support if you call them back!)

If you do call them back about this, make sure you post that info here.

Originally Posted by Zeromus-X

ChiroVette, is there anyone near you who runs a PRX system that you could hire for the night? (Likewise with the QSC system.) You seem to have a lot of hesitation regarding directionality, sound, etc, etc... and it seems like paying a soundguy to come out to make sure your $10,000+ investment is well spent would be good money.

I have considered this, but there are a couple of prohibitive factors:

First, I have no idea about the relative skill level of different sound companies who I might hire to come down and do sound for the evening. I could, for example, very easily end up thinking one set of cabinets is better than the other erroneously if the skill of the operator is different for both systems. I think this is a viable concern when testing out gear.

Second, I checked around and the people around me who have sound companies and this gear, whether QSC K/KW or PRX are very expensive. I could very easily end up spending $1,000.00, $500 for each company, in order to acid test the cabs. Honestly? This may sound cheap, but that is just a little lower than it would cost me (say from Mike Pyle) to for an EXTRA PAIR of tops! lol So if I was going to go that route, I think it would be a better investment, perhaps, to just choose one based on opinions here and buy and extra set of tops for a couple of hundred dollars more than renting out two sound companies would cost me.

[nchangin]

 

Originally Posted by ChiroVette

Is this an accurate statement that can be backed up with facts or is this just your opinion? Not criticizing, just asking if you are expressing opinion or fact here since I am looking at JBL cabs as a possible purchase.

 

It's a question I ask myself. I use JBL for my system as well so this topic is of interest to me in regards to service if the need arises. I prefer passive as I have backup passives if something goes bad.

[agedhorse]

 

Originally Posted by ChiroVette

Is this an accurate statement that can be backed up with facts or is this just your opinion? Not criticizing, just asking if you are expressing opinion or fact here since I am looking at JBL cabs as a possible purchase.

 

My opinion is that it's an inaccurate statement posed as a pot stirring question...

[Zeromus-X]

Originally Posted by ChiroVette

First, I have no idea about the relative skill level of different sound companies who I might hire to come down and do sound for the evening. I could, for example, very easily end up thinking one set of cabinets is better than the other erroneously if the skill of the operator is different for both systems. I think this is a viable concern when testing out gear.

Second, I checked around and the people around me who have sound companies and this gear, whether QSC K/KW or PRX are very expensive. I could very easily end up spending $1,000.00, $500 for each company, in order to acid test the cabs. Honestly? This may sound cheap, but that is just a little lower than it would cost me (say from Mike Pyle) to for an EXTRA PAIR of tops! lol So if I was going to go that route, I think it would be a better investment, perhaps, to just choose one based on opinions here and buy and extra set of tops for a couple of hundred dollars more than renting out two sound companies would cost me.

Where are you again?

Back in Hampton Roads, I can find someone with a QSC KW rig who's good at what he does for $200, including lights. We ran our PRX rig (635 over 618XLF) for the same price. At the $500 level you should not have to worry about the competency of someone behind the board, period. And if you do, perhaps it's time for you to start undercutting everyone out there.

It just seems to me that you've put more thought into this system than anyone in the history of buying {censored}. You've been going back and forth getting opinions for literally months if not longer. Unfortunately at the price point you're looking at, there's going to be a compromise somewhere. On top of that, there's no guarantee that you're going to get a cabinet that doesn't fail on you at some point, and realistically the backlog at the repair shop isn't as big of a deal as the "oh {censored}, what am I gonna do for sound this weekend" issue. My opinion would be that the only way to truly be safe would be to have a backup of anything that can go wrong; that's a backup sub, a backup top, a backup monitor. Going with similar tops and monitors sounds like an ideal way to have backups handy, but then you need to explain to the band who's paying you why you're taking one of their monitors away for the rest of the night and why your {censored} isn't working like they're paying you for. (Obviously if you're only using them in your own band then this doesn't matter quite as much, but if the market is as expensive as you're saying, why would you limit yourself?)

At $500 per gig for a PRX system you could literally buy our entire rig, trailer and all, run sound twice a week, and have the whole thing paid off in full in three months. That's a hell of a ROI.

[Gypsy Kiss]

I'm running a couple of small desk fans on the back of my PRX 635's, and with this the amps only get luke warm to the touch, which is a far cry from the first lot of gigs we did with them, you could've seriously burnt your hand before adding the fans, soooo much cooler now and I feel much better at gigs knowing my amps are not getting hot enough to cook with..

[agedhorse]

 

Originally Posted by Gypsy Kiss

I'm running a couple of small desk fans on the back of my PRX 635's, and with this the amps only get luke warm to the touch, which is a far cry from the first lot of gigs we did with them, you could've seriously burnt your hand before adding the fans, soooo much cooler now and I feel much better at gigs knowing my amps are not getting hot enough to cook with..

 

You might feel better but your speakers may not care one way or the other. They do not have human attributes, hot to you is not the same thing as hot to them.

[Dookietwo]

Saw this thread I thought I would add this.
Just last night a band I'm friends with played with 2 635 and 2 XLF(?) subs I believe per side.
The desk was a Studiolive 24. Sound was ok as they didn't have their soundperson and just recalled a scene from the last time they were there.
I felt the back of the amps after the first set. Warm enough to tell they were running but not a "darn these are hot" kind of thing. Subs were warmer for sure. SPL was average to loud in this venue.
I thought the combo was really good other than a light tree directly in front of the speakers! :-( I would be happy to mix on it.

Dookietwo

[agedhorse]

That's pretty much my experience too.

Originally Posted by Dookietwo

Saw this thread I thought I would add this.
Just last night a band I'm friends with played with 2 635 and 2 XLF(?) subs I believe per side.
The desk was a Studiolive 24. Sound was ok as they didn't have their soundperson and just recalled a scene from the last time they were there.
I felt the back of the amps after the first set. Warm enough to tell they were running but not a "darn these are hot" kind of thing. Subs were warmer for sure. SPL was average to loud in this venue.
I thought the combo was really good other than a light tree directly in front of the speakers! :-( I would be happy to mix on it.

Dookietwo

[OneEng]

I listened to both series cabinets in Guitar Center. I mean, seriously, how in the hell can one tell which PA is better sounding when using one or two vocal mics or simply playing an MP3 player through it? I just don't think that an in-store demo for a guy at my knowledge level yielded me ANY more information than I have already gleaned from you guys in this forum or from a couple of my buddies who live upstate and who I trust implicitly.

As I have stated, there really isn't a big difference in the sound between these two rigs IMHO.

There is a difference in price and weight.

If you are planning to use your system most of the time with tops over subs, then the 612's are the way to go.

If you are planning on using your system predominantly for just tops alone gigs, then the 635's are the best bet.

[ChiroVette]

Originally Posted by OneEng

As I have stated, there really isn't a big difference in the sound between these two rigs IMHO.

There is a difference in price and weight.

If you are planning to use your system most of the time with tops over subs, then the 612's are the way to go.

If you are planning on using your system predominantly for just tops alone gigs, then the 635's are the best bet.

This is why I have been leaning toward the 612's for most of the time I have been pondering this. You bring up a great point.

Originally Posted by Zeromus-X

Where are you again?

Back in Hampton Roads, I can find someone with a QSC KW rig who's good at what he does for $200, including lights. We ran our PRX rig (635 over 618XLF) for the same price. At the $500 level you should not have to worry about the competency of someone behind the board, period. And if you do, perhaps it's time for you to start undercutting everyone out there.

lol Probably a good idea, but I am not interested in doing sound for other bands. Maybe for a friend's band as a favor once in a great while.

Originally Posted by Zeromus-X

It just seems to me that you've put more thought into this system than anyone in the history of buying {censored}. You've been going back and forth getting opinions for literally months

True, but there is only one reason for that: I am not yet ready to buy and am still saving. So every time I see one of these threads I toss out questions like this for my own education, at least partly because you hear new stuff all the time. For instance, agedhorse brought up a problem with JBL's turnover rate for warranty repairs. This is NOT something I had ever heard before, so naturally, since I haven't purchased yet, I thought it would be prudent to ask more questions and make sure I am not leaning toward a future problem that may screw me up. There were a few other issues brought up in this thread regarding QSC Vs. JBL that I hadn't seen articulated quite that way, so I asked about them as well. No harm in trying to be sure when you aren't ready to buy yet, right? I mean, look, if I had the money in my hand, was ready to make the purchase, and knew I could actually make a choice and buy it now, then it would be absurd for me to be "agonizing" over this decision.

Stated another way, if I had the money to buy the system I would simply choose one and live with it. If I had the money several months back, I would have done the same. But I think that as long as threads like this keep popping you and I am still not ready to buy, it is smart for me to go back and forth like this as I am not in a position to implement a decision right now even if I wanted to. See my point?

[Gypsy Kiss]

 

Originally Posted by agedhorse

You might feel better but your speakers may not care one way or the other. They do not have human attributes, hot to you is not the same thing as hot to them.

 

Understood, but seriously man the only thing I like running that hot is a fireplace during winter not on the back of my speaker cab, and I'm pretty sure all dem little components inside the amp will thank me for it down the track..

[Gypsy Kiss]

Originally Posted by OneEng

As I have stated, there really isn't a big difference in the sound between these two rigs IMHO.

There is a difference in price and weight.

If you are planning to use your system most of the time with tops over subs, then the 612's are the way to go.

If you are planning on using your system predominantly for just tops alone gigs, then the 635's are the best bet.

I think there is quite a significant difference in the sound of these 2 boxes. I've been using 12";s over 18 subs for a long time and recently got the 635's , much better mid range clarity than a 12 and horn box, not so big a difference at low volume levels but pump them a little and the 3 way box will really leave the 12 for dust...Just my 2 cents anyhow.

[agedhorse]

Originally Posted by Gypsy Kiss

Understood, but seriously man the only thing I like running that hot is a fireplace during winter not on the back of my speaker cab, and I'm pretty sure all dem little components inside the amp will thank me for it down the track..

What about light bulbs, the engine in your car, your oven, etc. All of these are DESIGNED to operate at the temperature they do. The same for your electronics.

I have some stabilized low drift electronics that have thermostaticly controlled heaters to keep the operating temperature at design temp.

[Gypsy Kiss]

Originally Posted by agedhorse

What about light bulbs, the engine in your car, your oven, etc. All of these are DESIGNED to operate at the temperature they do. The same for your electronics.

I have some stabilized low drift electronics that have thermostaticly controlled heaters to keep the operating temperature at design temp.

I understand what you are saying man, but you have to acknowledge the amount of internet reviews out there about these cabs shutting down due to heat. While I fully understand that JBL has designed these amps to run hot ( still dos'nt make sense to me?) , other things factor in like how hot it is inside the room or outside in the sun. I'm not saying that JBL got it wrong, in fact 99% of the overheating reviews state in there review that the cabs sound fantastic but are unreliable because of the heat problem, so in my head why even test the theory? ...When a couple of fist sized all metal $8 fans elevates any chance of thermo ?????...Seems like a no brainer to me, cause the cabs really do sound nice, best sounding PRX model hands down.

[agedhorse]

Whatever, it may SEEM like a no-brainer but it (probably) can't hurt. Now the real question you should be asking is (IF that's the part that is overheating and IF the problem really is overheating, and IF there is even a problem)

There are tens of thousands of these speakers in the marketplace, rumors and reviews like this tend to show up with products that have huge numbers sold, and often by uneducated users (who think it's a good idea to set them in the direct sun disregarding warnings, and they are then multiplied by more uneducated users on internet forums because they have nothing better to do. That's my take after servicing many different brands and models over 30+ years at the industry level. I have also designed my fair share of commercially successful SMPS-class D powered products over the past 8 or 9 years, and have a recent patent in this particular technology and area so I have a pretty good idea of what the real data is.

Originally Posted by Gypsy Kiss

I understand what you are saying man, but you have to acknowledge the amount of internet reviews out there about these cabs shutting down due to heat. While I fully understand that JBL has designed these amps to run hot ( still dos'nt make sense to me?) , other things factor in like how hot it is inside the room or outside in the sun. I'm not saying that JBL got it wrong, in fact 99% of the overheating reviews state in there review that the cabs sound fantastic but are unreliable because of the heat problem, so in my head why even test the theory? ...When a couple of fist sized all metal $8 fans elevates any chance of thermo ?????...Seems like a no brainer to me, cause the cabs really do sound nice, best sounding PRX model hands down.

[Gypsy Kiss]

Originally Posted by agedhorse

Whatever, it may SEEM like a no-brainer but it (probably) can't hurt. Now the real question you should be asking is (IF that's the part that is overheating and IF the problem really is overheating, and IF there is even a problem)

There are tens of thousands of these speakers in the marketplace, rumors and reviews like this tend to show up with products that have huge numbers sold, and often by uneducated users (who think it's a good idea to set them in the direct sun disregarding warnings, and they are then multiplied by more uneducated users on internet forums because they have nothing better to do. That's my take after servicing many different brands and models over 30+ years at the industry level. I have also designed my fair share of commercially successful SMPS-class D powered products over the past 8 or 9 years, and have a recent patent in this particular technology and area so I have a pretty good idea of what the real data is.

Without fan I cannot place my hand on the back of the amp for more than a few seconds ,,,with fan they run luke warm just like my EV's ( which don't have fans either go figure?) After relaying my fears to the rep I bought them from here assured me that this was normal but If it makes you sleep better then by all means put a fan on them. See man to me the PRX stuff (particularly the 635) leaves no buffer for temp . Like as you said my car engine, yes it is designed to run ht but if the temp outside is also hot then maybe the car will boil and overheat? maybe not? ...I feel running fans on the boxes gives me that buffer and it does make me feel better at gigs with a packed room knowing that the amps are not getting as hot as they normally would. I used to own the JBL 512's and they ran quite warm but not as hot as the new PRX stuff???, why is that??.....

[loco_p_man]

 

Originally Posted by agedhorse

I have also designed my fair share of commercially successful SMPS-class D powered products over the past 8 or 9 years, and have a recent patent in this particular technology and area so I have a pretty good idea of what the real data is.

 

Congratulations - I am told patents are tough to come by and the criteria difficult to meet, so big kudos.

[ChiroVette]

Originally Posted by Gypsy Kiss

After relaying my fears to the rep I bought them from here assured me that this was normal but If it makes you sleep better then by all means put a fan on them.

lol You do realize that what the tech support guy told you was EXACTLY what agedhorse has been saying to you about this issue in the thread, right?

Seriously, the JBL guy himself basically told you that there is absolutely no need for a fan and that its ONLY function would be to make you "sleep better," thus acting like some electronic placebo. Again, that is precisely what aged has been telling you.

[Gaffle]

Originally Posted by Gypsy Kiss

I understand what you are saying man, but you have to acknowledge the amount of internet reviews out there about these cabs shutting down due to heat. While I fully understand that JBL has designed these amps to run hot ( still dos'nt make sense to me?) , other things factor in like how hot it is inside the room or outside in the sun. I'm not saying that JBL got it wrong, in fact 99% of the overheating reviews state in there review that the cabs sound fantastic but are unreliable because of the heat problem, so in my head why even test the theory? ...When a couple of fist sized all metal $8 fans elevates any chance of thermo ?????...Seems like a no brainer to me, cause the cabs really do sound nice, best sounding PRX model hands down.

I agree with you. Those amps in the PRX635's run/ran extremely hot. I use to own a pair but returned them after several shutdowns. (no I don't distort or run my source levels in the red).

The Sam Ash I returned mine to are still on the floor and I actually witnessed one of the pair shut down on one of the sales guys when he was demo'ing them for a customer, LoL. He tried to cover the mishap replacing the failed unit with a competitor's unit and turning it into an A/B comparison.

[agedhorse]

I have also discovered that DJ's are by far and away the biggest, and most prolific complainers of such problem. In fact, it's almost like they are the sole source of the problem. Either they are the most unlucky folks on the planet, they are the hardest on their gear or they are the most vocal complainers. I don't know which.

[Gaffle]

I think I saw several complaints of this unit on Prosoundweb and a couple on SoundForums and the strong majority of those guys aren't DJs. Pointing the finger at 'DJs' sounds typical of what many of them do (in some cases, it's justified).

I blame the manufacturers, JBL and Crown, for putting psuedo lay-flat heat sinks on their Foreman Grill of an amp. Isn't Class-D is suppose to be efficient with reduced heat dissipation? Don't bother blowing a bunch of technical I-know-hows at me because quite simply, something on the PRX635's is/was inherently wrong. Even when powered on and just sitting idle, the amp section is hot as a griddle. If you don't believe me, roll the dice and purchase one for yourself. If you don't like the speaker, you can return it or fry eggs on it.

BTW: I think the PRX635 is a very nice sounding full-range speaker, it just found it to be unreliable.

[Gaffle]

Originally Posted by Al Poulin

After all I've read about the 635 - and not just on DJforums - I would simply avoid them completely. There are so many reports of them shutting down, overheating - and not necessarily when at high output or when being abused. How often do you read of a Yorkville, QSC, RCF or even freakin' Behringer cab having thermal issues reported by so many users? Something is wrong in the design of the 635, simple as that. Whether it be a defective amp module or poor heat dissipation leading to thermal shutdown, JBL seems to have screwed up somewhere with this product.

Al

Right here.

[agedhorse]

You are certainly entitled to your own opinion, even if it isn't accurate.

My DJ comment stands as accurate, by far the majority of whining has come from that segment of the market. In fact, for another manufacturer of power amps that I am affiliated with, the failure rate of amps sold into the DJ market is much, much higher that the identical amp sold into other markets. The only difference being the users.

edit: oh, I see that you are a DJ... sorry if my comments offended.