Loudspeakers JBL VRX Rig: DOA(ish)

MNicolai

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Monday: Picked up x2 JBL VRX918SP's and x4 JBL VRX932LAP's

Tuesday: Tore open boxes for VRX loudspeakers and rang out the system. Things sounded good, all speakers worked, and all power pass-through cables and power input cables working fine.

Wednesday Thru 7pm Friday: Loudspeakers sat in storage.

7pm Friday: Set up system to experiment with position speakers. Both 932LAP stacks worked fine. The 918SP subs were paired together and one wouldn't turn on. The one that wasn't working was still passing audio and power through to the next sub, but wouldn't power on itself (which indicates the power and audio sources were good).

9pm Friday: Gave up troubleshooting sub awhile ago and went on to try to use lone working sub on its own when lone working sub turned out to not be working. Both subs went belly up. The Power indicator LED's wouldn't turn out, but I know I still had power on that extension cable because I happened to have the our LS9 also on that wall outlet.

10pm Friday: Triple-checked voltage switches set to 115v. Triple-checked all power input cables (provided by JBL) were correctly wired. Triple-checked all power pass-through cables were correctly wired (materials provided by JBL but some wiring labor required of end-user). Check that the push-to-reset buttons had not been tripped.

Scanned JBL's website for information and couldn't find so much as a tech support phone number.

Now I have two effectively DOA VRX subs. Monday morning the vendor will be getting a flustered call from us that I imagine will be passed onto JBL and then for all I know onto Crown. In the meanwhile, I want to learn as much about this problem as is possible before we have to worry about driving these things across creation or freight shipping them. Anyone have any ideas?
 
Have you tried switching outlets? Have you tried powering up each component individually? I haven't used a VRX system in a while, but I remember last time I used one I had the same gear you have. We had the same issue going on because we had bad power running to our system. The house was trying to run the entire thing off of one 20A circuit, it didn't blow the circuit breaker but some of the cabinets wouldn't turn on.
 
I tried three different 20A outlets. One included the circuit our LS9 was on, so I know the system was getting power. I also tried another on the front of the stage and a third on the downstage wall.

The third wall outlet was part of our clean power system. Where a pair of 932LAP's were plugged into, I inserted the sub as the first time in the chain, then pass-thru to the bottom 932LAP, and pass-thru to the top 932LAP. 12AWG extension cables, no longer than 50' power runs. The 932LAP's continued to power up and work fine while the subs sat there and didn't show any signs of life.
 
Most of the time it's internal connectors that have been agitated.

That's where I'm putting my money but if I crack it open up visually inspect it then I think I void the warranty.
 
Don't touch it just start calling anyone who do something about it.
If you get the right people Harman isn't that bad to deal with.
 
I imagine these are new. Based on past experience with JBL, you'll have replacement boxes very soon. If you bought them from a brick and mortar store, they'll probably just swap them out.
 
I imagine these are new. Based on past experience with JBL, you'll have replacement boxes very soon. If you bought them from a brick and mortar store, they'll probably just swap them out.

I don't anticipate any problems; I'm
more curious as to the cause than anything else and how something like that could make it past Quality Control.

Whatever replaces these will get some burn-in type abuse right away so I can be confident they aren't as likely to fail again right away.

The inconvenience of getting them replaced by the vendor isn't what has me concerned. The damage done is to my long-term trust that these cabinets will not all go belly-up at the top of a show, and there's little my vendor, JBL, or Crown can say that will undo that damage.
 
Talked to JBL & our vendor.

Cause of failures unknown -- must be problem with amplifier module -- possibly a faulty internal fuse within the amp module not accessible by end-users.

Checked all our power cables, pass-thru cables, circuit voltages, line select switches, push-to-reset buttons, and internal molex connection between amp module and speaker -- no dice. JBL rep said we've tried the things that you can try and that it was time to make a warranty claim.

Swapping the speakers with the vendor on Monday. They say they've not seen this type of failure before and that they sell a lot of these units and haven't had any problems. That said, they did look into their Returns log and found a similar case with a pair of subs several months ago. No idea what the common factor is between our subs and that customer's subs other than it's highly improbable that they came out of the same batch.

Once the new subs are in, I'll run them hard the first few nights we've got them and hopefully if they're going to fail, they'll fail then instead of during a show.
 
At least you can swap these out locally instead of shipping them back to CA. We have a lots of VRX and Itech/XTI products and have never had any problems, although we choose to keep the components separated. I've also never heard of this happening, I wouldn't worry about the replacement units failing. Let us know how it goes.
 
At least you can swap these out locally instead of shipping them back to CA. We have a lots of VRX and Itech/XTI products and have never had any problems, although we choose to keep the components separated. I've also never heard of this happening, I wouldn't worry about the replacement units failing. Let us know how it goes.

Very true, though I was hoping I could just drive the amp modules back but the shop understandably wants the whole units.
 
Got our subs swapped yesterday. Fired them up today and one died after 30min of music playback. Didn't even have them close to peaking out.

Second one I unplugged before it had a chance to die.

I know 0dB on the output of the LS9 is the peak level for the subs, and I had these things cooking at between -18dB and -10dB, so unless I'm crazy they should have been fine.

Checked power cables (again) and found nothing awry. Still had power and audio pass-thru to the tops and they were kickin' fine.

JBL and the vendor have both had phone calls with me where we eliminated any question that these failures were our fault so I can only surmise there are some serious quality control problems going on somewhere along the line.
 
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I've had the same thing happen, it was internal connections each time.
A little silicone in a few places and all is well.
But having this happen to new speakers is unacceptable.
 
I live In australia and we just imported a VRX system not long ago.. we have used the gear a few times no problem.. had the rig cranking last week, did a small job in a mall today so it was only low level, after about 2 hours 1 of the subs just died, no power lights.. nothing. Sounds similar Not happy about it tho :(
 
Had our two subs in for repair (so far three of four subs that had been in our possession had failed).

Got them back from repair yesterday -- the shop broadly replaced all 3 PCB's in the power amp modules.

Ran fine tonight for several hours. Started around 6p, but by midnight one of the two had failed again. Got a show tomorrow with the system do we'll see if the other sub makes it through the show or not.

In the meanwhile, all of our PCB's have been shipped back to JBL for diagnostics, who last I heard was still considering this an isolated incident. Clearly it is not.

Getting' tired of this...
 
LaserShowProductions, was your system bought through Australian channels? If so, Jands will be the ones to handle the warranty claims etc. 02 9582 0909.
If it was imported through other channels, you may be on your own or at least on billable time...
 
I know 0dB on the output of the LS9 is the peak level for the subs, and I had these things cooking at between -18dB and -10dB, so unless I'm crazy they should have been fine.
I just noted this. Are you saying you have -18 to -10dBu at the output of the console or that you run the console with -18 to -10dBFS level on the output meters? The LS9 meters show the digital signal level in dBFS rather than the analog output level in dBu such that a nominal 0 level on the meters equates to a +24dBu output and a +4dBu typical nominal console output level would be -20dBFS on the LS9 meters. So -18 to -10dBu out on an LS9 would be -42 to -34 on the output meters while -18 to -10 on the console meters would relate to +6 to +14dBu analog output level. You may also want to verify that the LS9 output bus meters are set for "POST ON" as they can also be programmed as "PRE EQ" or "PRE FADER" and thus the actual output levels could differ from what the meters indicate.

Also related to signal level, the level control on the rear of the VRX918SP is set such that at full attenuation (full counterclockwise) the sub has a nominal sensitivity of +4dBu and a clip level of +20dBu and thus this is the normal setting for use in pro systems. Turned full open (full clockwise) the levels are a nominal -12dBu and a maximum +4dBu.

Assuming there are no intermediate devices like a system processor, you'd probably want to have the attenuation on the VRX918SP set all the way down or full counterclockwise and run the LS9 at a nominal -20 on the output meters with the meters set for "POST ON". If you were running the LS9 at -18 to -10 on the output meters, a nominal output level of +6dBu to +14dBu, into the VRX918SP with its level control anywhere other than at full attenuation it seems that you could be overdriving the sub.


You've probably already done this but another thing to check is that when you loop VRX918SP subs you want the "AUDIO OUT" switch on the first sub set for "BYPASS" otherwise the next sub will be getting only the 80Hz high pass output.
 
Excuse my brevity, I'm walking between meetings while I respond.

I run the LS9 so that when my Stereo meters clip is synonymous with when the sub's clip. It's set to meter Post On.

That said, program level is never high enough to accidentally clip.

918's and 932's are attenuated fully counter-clockwise.

I have them flown such that each stack is a 918 and two 932's. Rach stack is powered from a single 20A feed. The Hi-Pass is engaged for the loop-thru to the 932's.

I've had someone stand on stage watching the peak light on a very bass-heavy song. It takes pushing LS9 to a sustained clip level to get the peak lights on the subs to so much as flicker. The only time I've pushed them that high is while deliberately seeing how much headroom I had while I had someone on stage ready to alert me the moment they started peaking.
 
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I just got 4 vrx918sp's about a month ago, first three gigs went well, speakers functioned properly and sounded great. Set up for gig #4 last weekend and ran into the same issue, one of the subs wouldn't power on but still passed input signal and ac.

Wondering if there have been any developments in your story or if you've come to any conclusions as to what is causing this problem?
 

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