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View Full Version : JBL PRX612m problem.



phunior
04-07-2012, 11:49 AM
Hello All,

It's nice to see that this forum is up and running again.

One of my 612's has a slight distortion and when I turn it up I can faintly hear a clicking (possibly a rattle) sound. I used my other 612 speaker to do a side by side comparison. From a distance you can't really tell any differences in sound. I then hooked the speaker up to a mackie mixer and killed the highs/mids and left only the lows on the EQ and definitely noticed some distortion when turned up.

Does this sound like a major issue? I thought I would get a second opinion before I decide to send it back to JBL.

Any advice would be greatly appreciated.

Thank you.

Djjohnnybertone
04-07-2012, 12:04 PM
You probably blew out your woofer

Bill Fitzmaurice
04-07-2012, 05:14 PM
You probably blew out your woofer+1, probably via over-excursion, smacking the voice coil. Complete driver failure will likely happen eventually.

jayhwk
04-07-2012, 06:21 PM
I'd send it off to JBL and hope they don't deny your warranty claim because of misuse.

Has it been consistently run hard over its lifetime?

Djjohnnybertone
04-08-2012, 01:57 AM
Are you familiar with the limiter lights on the back? Because if you constantly limit out your cabs, the woofers won't be able to handle all the power and either rip the coil, or blow completly. Do you notice any distinct smell comin from the port on the back? Like any burning smell? Because that would usually indicate that your burning your voice coil and over powering it

Bill Fitzmaurice
04-08-2012, 09:36 AM
Are you familiar with the limiter lights on the back? Because if you constantly limit out your cabs, the woofers won't be able to handle all the power and either rip the coil, or blow completly. Do you notice any distinct smell comin from the port on the back? Like any burning smell? Because that would usually indicate that your burning your voice coil and over powering itOver-excursion is the result of too much low end content, and can occur well below the driver's thermal limits. Not having subs or improper cross-over setup is the usual cause.

phunior
04-08-2012, 10:48 AM
Thanks for the help guys. I have only used the speakers a handful of times since I've had them, however the times I did they were used at very loud volumes playing Hip Hop music. This matches the over excursion explanation.

@Bill, I guess this is a good reason to start using those Tuba 30 plans I bought from you over a year ago...

Bill Fitzmaurice
04-08-2012, 12:45 PM
Thanks for the help guys. I have only used the speakers a handful of times since I've had them, however the times I did they were used at very loud volumes playing Hip Hop music. This matches the over excursion explanation.

@Bill, I guess this is a good reason to start using those Tuba 30 plans I bought from you over a year ago...If you really want to destroy a good pair of tops run them with a lot of lows at high volume, you'll get your wish in short order.

SummitAudioDJ
04-08-2012, 03:10 PM
You really should break in a new pair of speakers before slamming them hard with any music. I would save yourself the shipping cost and disappointment and just get the woofer reconed. This is fairly easy to do yourself if you follow the directions and take your time. It will cost you half of what a whole new driver would. Most companies won't touch fried coils or torn spiders for free warranty repair.

phunior
04-08-2012, 08:55 PM
If you really want to destroy a good pair of tops run them with a lot of lows at high volume, you'll get your wish in short order.

Yeah that was not smart of me.. it was definitely a lesson learned. I will call JBL tomorrow and see what my options are.

As far as reconing it myself, I have looked into reconing kits but am some what hesitant because I've never done it before.

Windows 95
04-08-2012, 09:38 PM
As far as reconing it myself, I have looked into reconing kits but am some what hesitant because I've never done it before.If you have the kit that matches your raw speaker, it's extremely easy.


http://www.youtube.com/watch?v=lxGswEB3O_Q

phunior
04-08-2012, 11:28 PM
[QUOTE=Windows 95;60482]If you have the kit that matches your raw speaker, it's extremely easy.

Nice video, thanks for the post Windows 95.

jayhwk
04-08-2012, 11:32 PM
There is a chance JBL will repair it under warranty if they find that there was a manufacturing fault (after all, your other speaker was run just as hard but didn't fail), but the warranty would certainly be invalidated by trying to recone the driver yourself.

Windows 95
04-08-2012, 11:44 PM
There is a chance JBL will repair it under warrantyThis would probably be your best bet, because they have a 5 year warranty on their speakers.

http://www.jblproservice.com/warranty_faq.htm


Why can't end users purchase cone kits?
Because replacing a driver's cone, suspension and voice coil requires special test equipment, tools and training.

We recommend you take your product to one of the over 300 service agencies throughout the United States with factory trained technicians on staff. Check out our Service Center Listing to find a JBL authorized service center near you.
http://www.jblproservice.com/service/index.html

Smithall Electronics
2001 Vine St.
Cincinnati 45202
(513) 381-2828

Transducers, Electronics,
EON, LSR, 6208, JRX, PRX,
MPro & SoundFactor, JBL Dealer

SummitAudioDJ
04-09-2012, 01:13 PM
Each speaker may not have been running the exact same signal especially if running in stereo. Also , one could have been EQ'd, crossovered , or gain set differently. Even with everything set exactly the same it is possible for one driver to fail and not the other.

phunior
04-11-2012, 02:04 PM
Thanks Windows 95,

I have an appointment with Smithall to bring in my speaker this Friday. They told me that if there's anything "burned out" in the speaker, then it isn't covered under manufacturers warranty.

I looked up the price for the 262F-1 woofer online and it has a price around $250. This may very well turn into an expensive fix.

On a side note, I started my build for a BMF T39. Seems like a great project especially since the weather here is warming up I can work outside.

Thanks for all the input everyone.

Bill Fitzmaurice
04-11-2012, 02:16 PM
I looked up the price for the 262F-1 woofer online and it has a price around $250.

A recone should run around half that.

Djalby
06-24-2012, 07:20 PM
Had same problem. Unscrew grill take out sun. And tighten tweeter. (driver ). Does your amp get real hot. ?

Frank Obrien
03-31-2015, 09:43 PM
There is most likely a manufactures deficit in the coil. I have seen this a number of times with cheaper Chinese built drivers. (Sorry in may say Built in USA but the price is a give away the components are from China) I have had drivers I sell from a good Taiwan company and it happens. Ive replace it with a new driver (Woofer) for the customer.
Some have mentioned operational use as the fault. I would expect issues with the other driver as I will assume they are used together? Others have mentioned the limiter. Bottom line is that these systems are designer to not allow over loading. After all they have control of the amp and have assumed a monkey might be using the system with everything cranked. Most of these systems have an internal limiter after everything we may do. They save a lot of warranty money that way.
Also if you were able to over load it, the scraping of the coil would be far more pronounced.
Return it. And have a loud day :)

fueledbymusic
04-01-2015, 12:27 AM
^^^ A good bump there! 3 year old thread!

Bill Fitzmaurice
04-01-2015, 09:10 AM
^^^ A good bump there! 3 year old thread!+1. One would suspect that the OP had things sorted out at least two years ago. :)

Oceanglenn
12-23-2015, 12:15 PM
I realize this is an old thread but I just saw it searching for something else on line. In case anyone stumbles across this as I did I present the following:
I had a similar rattling / clicking sound in a JBL PRX 615M that worsened with increasing output power levels, and it turned out that the plastic high frequency horn had worked its way partially loose and was vibrating inside the speaker. I removed the power amp module from the back of the speaker and was able to re-tighten the horn which immediately fixed the problem. Might not be your problem but worth a check before assuming more expensive problems might be occurring.

Glenn

phunior
01-27-2016, 10:12 AM
Thanks for the response. If I can recall correctly, I was able to have it sent in to JBL for repairs then sold the pair after getting them back.