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View Full Version : JBL prx 625 or 635?



rohan
03-19-2012, 03:45 AM
Hey guys,

I'm about to head out and get some new JBL PRX speakers - Question is 625 or 635?

Currently leaning towards the 635's.

windspeed 36 has already commented that the 635's offer far better sound quality over the 625's for only a slight loss of volume?

I'm looking for maximum volume - but without harshness when run near full volume.

Anyone else have any experience with the PRX's?

windspeed36
03-19-2012, 04:40 AM
Also I can't remember if i mentioned it - but there is cause for concern with the 625 due to overheating issues

rohan
03-19-2012, 04:42 AM
but there is cause for concern with the 625 due to overheating issues

But not the 635's?

windspeed36
03-19-2012, 04:52 AM
I haven't heard about the problem with the 635's.

This is purely theoretical but one would assume while both having 1500w amplifiers in them the 625 would use more of that 1500w because its driving 2 15" 525W drivers as opposed to the 635 which is only driving a single 15" driver and a 6" driver. Thus the 625 will generate more heat....purely theoretical.

rohan
03-19-2012, 05:12 AM
I haven't heard about the problem with the 635's.

This is purely theoretical but one would assume while both having 1500w amplifiers in them the 625 would use more of that 1500w because its driving 2 15" 525W drivers as opposed to the 635 which is only driving a single 15" driver and a 6" driver. Thus the 625 will generate more heat....purely theoretical.

Makes sense

GaFFLe
03-19-2012, 09:32 AM
Also I can't remember if i mentioned it - but there is cause for concern with the 625 due to overheating issues
I had overheating issues with the PRX635's and took them back. I've read that JBL has corrected the issue but I'm not sure. They denied there was an issue when I had mine. This was about a year ago. They get/got extremely hot to the touch even when sitting idle.

GaFFLe
03-19-2012, 09:36 AM
I had overheating issues with the PRX635's and took them back. I've read that JBL has corrected the issue but I'm not sure. They denied there was an issue when I had mine. This was about a year ago. They get/got extremely hot to the touch even when sitting idle.
http://blog.channelliveproductions.com/2010/12/11/jbl-prx635-update.aspx

Cris1605
03-19-2012, 12:35 PM
I do not think JBL has corrected the thermal shutdown issues. A club that I DJ at normally just bought a pair of 635's from local Guitar Center in January and they were shutting down all night. I was watching the clip lights because they were right in front of me. It seems if you play them at a high level constantly they just shut down for a few minutes to cool down. Not a very good feature in IMO if you can't push your equipment without them turning off suddenly. I made sure to keep them off the limiters, but they shut off about 6 times that night..both would thermal at different times, and once at the same time

windspeed36
03-19-2012, 03:00 PM
You shouldn't need to push your equipment hard - if you are then you haven't got enough rig for the gig

Cris1605
03-19-2012, 07:54 PM
The speakers were not hitting the limiter when they went into thermal shutdown, and the heat sinks of the amps were at least 15 feet away from the nearest wall. If a speaker can't be pushed without the limiters coming on, then the manufacture should set the limiters to come on faster to keep them from shutting down don't you think? Or design a better way to keep the amp running cooler. Again, this isn't my rig. They are used as front fills on a stage at a club I DJ at..Just thought I'd share the experiance because these JBLs are 2 months old, and they are having the same issues I have read from others ****** back from when they first came out.

windspeed36
03-19-2012, 08:07 PM
I'd be also having a look at the QSC KW153 which is in a similar price range - and I haven't heard about any thermal issues with any of the QSC KW range - they have inbuilt fans so...

GaFFLe
03-19-2012, 08:53 PM
The speakers were not hitting the limiter when they went into thermal shutdown, and the heat sinks of the amps were at least 15 feet away from the nearest wall. If a speaker can't be pushed without the limiters coming on, then the manufacture should set the limiters to come on faster to keep them from shutting down don't you think? Or design a better way to keep the amp running cooler. Again, this isn't my rig. They are used as front fills on a stage at a club I DJ at..Just thought I'd share the experiance because these JBLs are 2 months old, and they are having the same issues I have read from others ****** back from when they first came out.
This is true and I have attested to the failures. The same speakers I returned to the Sam Ash are still there on display and have yet to be sold. I recall going there when they were demo'ing them to a customer and one of them shut down prematurely. I just chuckled and was glad I returned them before it was too late. I ended up going to some passive EV QRX212/75's and haven't looked back.


I'd be also having a look at the QSC KW153 which is in a similar price range - and I haven't heard about any thermal issues with any of the QSC KW range - they have inbuilt fans so...
The big issue with those is the 87 lb. per weight.

Incognito
03-20-2012, 03:19 AM
I ended up going to some passive EV QRX212/75's and haven't looked back.


The big issue with those is the 87 lb. per weight.

The passive EV QRX212/75 weighs in at just over 80 lb so an extra 6.5 lb with a built in amp & processing isn't bad (though I personally would go for the EV QRX212/75 if I had to choose between the two but then I would go for the JTR 12x before both of them).

GaFFLe
03-20-2012, 10:41 AM
The passive EV QRX212/75 weighs in at just over 80 lb so an extra 6.5 lb with a built in amp & processing isn't bad (though I personally would go for the EV QRX212/75 if I had to choose between the two but then I would go for the JTR 12x before both of them).

I knew someone would chime in about the QRX's weight but it's heavy'ish for a reason. It's very well constructed and has higher end components than a KW153. To me, it's actually just easier to lift the QRX212/75 than the KW153 despite it being only 7 lbs. lighter. Maybe it has to do with the QRX's ergonomics or internal component's layout.

The big plus with a KW153 is you have the convenience of pole-mounting a KW153... BUT... pole mounting 87 lbs. is not an easy chore, even when you're using the lay-down technique. Not only is it not easy to mount, it's dangerous when trying to take the speaker down solo (after a long gig) and dangerous from a standpoint of such a heavy and tall speaker on a more-than-likely insufficient speaker stand (most people end up buying standard $39 On-Stage stands). All that weight for a solution that doesn't get any louder than my ZXa5's... just goes a little lower with the advantage of a 3rd driver for clarity.

Not saying the KW153's are bad at all. They're pretty good from what I've heard. I will say that on the edge of clipping, the QSC limiters start to get harsh and break up more so than the JBL PRX line (615's and 635's). THe JBL's sound really smooth even close to or at clipping levels. Reliability is the PRX's big question mark. I actually recommended the PRX635's early on to a female DJ friend and she hasn't had any shutdown issues (ever). She's a happy camper with them as they definitely sound good, have very good bass response even w/o a sub and are not too heavy at only 60 lbs. each.

I considered getting the JTR Triple 12x because it's pole-mountable but I was concerned with the coaxial design (its projection abilities) and its high compression driver size (I think it's only 1"). Also, it seems as though he changes/improves his designs every year and at the time, there weren't enough reviews out there to sway me.

windspeed36
03-20-2012, 02:57 PM
You can pole mount the 635's

Incognito
03-20-2012, 04:22 PM
I knew someone would chime in about the QRX's weight but it's heavy'ish for a reason. It's very well constructed and has higher end components than a KW153. To me, it's actually just easier to lift the QRX212/75 than the KW153 despite it being only 7 lbs. lighter. Maybe it has to do with the QRX's ergonomics or internal component's layout.

The big plus with a KW153 is you have the convenience of pole-mounting a KW153... BUT... pole mounting 87 lbs. is not an easy chore, even when you're using the lay-down technique. Not only is it not easy to mount, it's dangerous when trying to take the speaker down solo (after a long gig) and dangerous from a standpoint of such a heavy and tall speaker on a more-than-likely insufficient speaker stand (most people end up buying standard $39 On-Stage stands). All that weight for a solution that doesn't get any louder than my ZXa5's... just goes a little lower with the advantage of a 3rd driver for clarity.

Not saying the KW153's are bad at all. They're pretty good from what I've heard. I will say that on the edge of clipping, the QSC limiters start to get harsh and break up more so than the JBL PRX line (615's and 635's). THe JBL's sound really smooth even close to or at clipping levels. Reliability is the PRX's big question mark. I actually recommended the PRX635's early on to a female DJ friend and she hasn't had any shutdown issues (ever). She's a happy camper with them as they definitely sound good, have very good bass response even w/o a sub and are not too heavy at only 60 lbs. each.

I considered getting the JTR Triple 12x because it's pole-mountable but I was concerned with the coaxial design (its projection abilities) and its high compression driver size (I think it's only 1"). Also, it seems as though he changes/improves his designs every year and at the time, there weren't enough reviews out there to sway me.


No dispute here on the superior build quality & sound quality of the EX QRX 212/75 when compared to the QSC KW153 since as I said I would take the EV over the QSC in this comparison. I was just stating that from a weight perspective there's not much difference between the two & that the extra weight is sort of justifiable for the extras they're throwing into the picture.

Pole mounting a 87 pound speaker isn't that bad if you use the lay down technique but the trick is to do it with the speaker stand NOT extended. The other part of the trick is with the speaker stand used, if you use stands such as the Frankenstand F2 (a few years ago when I was asking about them I was told by Mike they could actually do up to 90 lb but there wasn't any speakers on the market at the time in that weight range). This way the powered speakers stands will raise & lower the speakers for you thus taking a lot of the hard part out of the equation. I do agree with you with people buying expensive speakers but then cheaping out for cheap entry level speaker stands when they should be investing into proper stands at that weight range. The EV ZXa5's are noted for going loud & are among the loudest powered speakers in it's price range but as you mentioned the 3-way vs 2-way makes a difference in clarity in favor of the QSC.

I think as far as sound quality goes QSC has gone down hill with it's entry level speakers ever since the HPR series but the KW series does sound better then the K series. The HPR series was said to clip easily as well but what I found was when I used my DBX driverack instead of the built in processors I was able to squeeze out just that more out of the speakers but really even with the built in processing I was able to fill large spaces about time the limiters started to engage.

One thing I like about Jeff is that he's always working to improve on his designs with a few exceptions most of his improvements are bolt on improvements & if you really wasn't the latest improvement he is willing to sell you the parts to bring you up to the latest spec. There are plenty of reviews out there on the 12x as well as many of his other designs from a wide range of users using the same speakers for a variety of applications & they have been getting good feedback on all fronts. I must admit that I didn't know the 12x was pole mountable & this was one of the things that made me go for the 8x over the 12x. What I found though was though in our minds we THINK we'll need the largest speakers available to cover a certain task, in the end what we really need may come in a much smaller package ( I was going to relegate the 8x to monitor duty & use the 12x as mains before I had received my 8x but once I got to use them in actual gigs with my six Growlers I found the 12x just may of been over kill).

HipBonanza
05-06-2012, 01:52 PM
Hi There the thing people need to bear in mind about the tech used in these speakers is that they have inbuilt thermostats that cut
off when the temperature of the amps get to high.
This is to stop idiots from melting them from pushing a really hot signal into them.
The class d mosfet amplifiers are a different breed to older tech and need treating with a cooler signal kept in the green

As long as you keep things TOTALLY out of the red they will go on all night with out any issues what so ever. Jbl have thought of everything
with this speaker.
We had an 7.5k opus hd rig before with 2x double 18s and opus hd amps and i have to say the jbls with the xlf subs are
way better louder and clearer then the opus rig and there technically 2 kw less rms ???? it defies reason this really is the best possible system you will find
for the money INCREDIBLE :love:

For any one still doubting i was using a rcf 4pro system last year. The jbls wipe the floor with them not quite as clear and transparent but you will get way more
out of them then any other active system in that price range. i won't comment on the qsc's there not even close to competing with these although have a more musical
sound. there just not capable of producing the same levels of sound as these prx monsters

Bottom line for upto 500 people you wont need any more then 2 prx625 and 2 618xlf subs in a medium sized hall/club

Al Poulin
05-06-2012, 02:43 PM
I'd rather use properly designed powered speakers (can you say improved heat dissipation AND/OR reduced heat production from the start) and simply better protected from failure than the PRX. There are complaints and problems on MANY forums mostly about the 635s and 618XLF subs. JBL customer service also seems to be complete crap lately - we have a member on Harmony Central who has been without his 618XLF for a month and a half now which is completely unacceptable. This after day after day of leaving messages to JBL without getting a call back...

I would avoid the company completely at the moment. Have you seen the alarming number of USED 635s on Ebay?

I have been using Yorkville and RCF powered speakers for the last 5+ years without a single failure of any kind. To have to constantly babysit a speaker because it might thermal if used too hard is ridiculous. These are PA speakers are they not? Live sound and DJ applications can be demanding and sometimes these products will be subject to less than ideal conditions. You would think a company like JBL would be aware of this? I think they cheaped out in the design somewhere (why do these speakers get ridiculously warm just idling?) although they will never admit it...

Look into Yamaha DSR or newer DXR powered speakers (just one example) if you want excellent sound and high performance without having to worry about thermal failure during your performance.

Al

GaFFLe
05-06-2012, 04:10 PM
I'd rather use speakers properly designed (can you say improved heat dissapation AND/OR reduced heat production from the start) and simply better protected from failure than the PRX...

I would avoid the company completely at the moment. Have you seen the alarming number of USED 635s on Ebay?

...To have to constantly babysit a speaker because it might thermal if used too hard is ridiculous. These are PA speakers are they not? Live sound and DJ applications can be demanding and sometimes these products will be subject to less than ideal conditions. You would think a company like JBL would be aware of this? I think they cheaped out in the design somewhere (why do these speakers get ridiculously warm just idling?) although they will never admit it...

Al
There it is...

MikeLtheDJ
05-06-2012, 04:33 PM
I've got the prx515 series. One of my speakers shuts down for a second then comes right back. This only happens after a prolonged play time at a significant volume. Last time it happened was after 6 hours of playing at a high volume. ( not clipping ). I brought the speaker to a service shop where they say they. Could not replicate the issue. If I'm doing a typical wedding or a birthday party then I have no issues. I posted about this issue and a member suggested a resolution, computer fans. Its sad that a company like JBL is denying a problem. Don't get me wrong, on my opinion these are the best sounding speakers out there. But.....
I don't know what I would choose if i had to buy again.

Sent from my DROID RAZR using Tapatalk 2

DJMC
05-07-2012, 12:25 PM
I voted for the PRX 635.

Although in reality, I'd choose the 12's for tops, and use two PRX 618s-xlf subwoofers instead.

rockey
05-31-2012, 11:30 AM
I have purchase a pair of jbl 635 2mts ago and from day one had problems with,rackling sound which i took them back was repair and overheating and shutting down several times,i will never recommed this jbl 635 for dj"s, dealer giving me a run around and don't want to change them,contact jbl myself they told me that there is a recall call on the first shiptment which has the over heating problem,still dealer don't want to change them,need some help thank's.

bumpyjonas
05-31-2012, 09:40 PM
This seems to a problem with the PRX 635's that just wil not go away.

windspeed36
05-31-2012, 10:07 PM
Qsc KW153 instead?

richard stringer
06-01-2012, 05:59 AM
I love the clarity of the PRX635, but ARRRGGGHHH, the overheating problems, come on JBL you sperm stains, you're supposed to be one of the best live sound speaker companies in the world, sort it out.

windspeed36
06-01-2012, 06:29 AM
The 635's often have a pretty bad noise issue too