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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Morten Nilsen on December 08, 2013, 07:29:06 pm

Title: Problems with the new JBL PRX718XLF subs??
Post by: Morten Nilsen on December 08, 2013, 07:29:06 pm
Hi everyone, I`m new to this interesting forum, and I have a problem witch I hope somebody can help me with.
I just got 2 new PRX 718XLF subs from JBL delivered, and took them out for their first show this weekend. I`d tested them at my house before taking them out, and they worked just fine. Got to the gig after a short 3 mile drive, got the gear up, and went to switch the subs on. Poof sparks in the fan hole, and the fuse blew out. Replaced the fuse and tried again, same thing happens. and get this, on BOTH sub`s!! Now, my top speakers, JBL PRX635`s, were fine. They were all on the same power source, and only the subs shorted. Some more info, I live in Norway and we use 220V. In my house and everywhere, for "normal" use, same at the gig. The speakers spent the night in my van, and the temp. outside was about 18-19 degrees F, (-7 C.) Inside temp.  around 75 F.  Could there be a problem with condensation?? But why only with the subs?? All normal things were checked, switched power cables, different sockets, etc.  :-\
Thanks alot!!
I wish everybody a happy holiday season, greetings from freeezing Norway!!


A quick update on this issue today: as it turns out, the PRX718`s have a production flaw in one of the components in the amp. module wich causes the amp. to blow up!! I was explained this today by the distributor/dealer of JBL/Harman here in Norway today. It seems that the problem is only occuring in the UK, Norway, and Australia. For now. JBL has no fix for this yet, so I really don`t know what to do  :'(
Does anybody out there have a contact inside Harman/JBL, that I could get in touch with??
Title: Re: Problems with the new JBL PRX718XLF subs??
Post by: sam saponaro on December 08, 2013, 08:54:58 pm
here in freezing ny state usa my gear sits in my truck in temps below zero often at times.I allways give it time to come up to temp at the venue befor powering up and no probs.So I don't think thats your problem.
Possible there is a miss wired outlet at the venue you played? I've had that befor once played a place were ground and hot were reversed.
Title: Re: Problems with the new JBL PRX718XLF subs??
Post by: Steve Garris on December 09, 2013, 04:24:11 pm
Very sorry to hear this Morten! I can't elaborate on what went wrong, but have you contacted the seller or JBL regarding this? As as owner of PRX600 series I'll be very interested in hearing about the outcome. Good luck!
Title: Re: Problems with the new JBL PRX718XLF subs??
Post by: Morten Nilsen on December 11, 2013, 06:27:05 pm
Very sorry to hear this Morten! I can't elaborate on what went wrong, but have you contacted the seller or JBL regarding this? As as owner of PRX600 series I'll be very interested in hearing about the outcome. Good luck!


I was in touch with the JBL`s agent here in Norway today, and they said that they`d stopped selling the prx718`s for now, due to some "start up" problems as they put it. They did not seem to happy to help me, since I bought the sub`s from the US, but we`ll see what they`ll come up with. :)