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Question about JBL PB12 Subwoofer

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JBL PB12 standby WAY too sensative

I listen to classical music that tends to have a very wide dynamic range. At lower volume levels this amp turns off, or even worse, flickers on/off very rapidly. Just turning the music up is not possable unless I want my house to rumble to the DJ's voice after the piece is over. Is there a way to disable this standby? Or better yet, is there a way to lower the threshold or extend the time before it goes to standby? Like 5-10 minutes after threshold is met, unless it is again exceeded. Like a how a screensaver works on a PC. Great sounding system, have had it for about 6 years. Thanks for any solutions. And a shaking of the fist for any bad news. :P

Posted by hermesvs on

  • hermesvs Aug 12, 2007


    The woofer still has the sensative standby problem but now is very distorted. I was hoping my problem was different then the countless others I've been seeing, but this appears to look more and more like a bad amp. Needless to say it is unplugged until I find, or can afford, a solution.

    Please prove me wrong with an easy (or at least cheap) fix.



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Capacitor C42 is bad. You should have a 15 minute pause before going back into mute mode. If the cap. is really bad it will distort the sound and cause cutoff.

David S.

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Posted on Feb 12, 2009


Jerry Greenberg

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It sounds like there are failing parts in the amp and possibly in the power supply sections. You should contact JBL to find out their service rep in your area.


This unit will not be cheap to service. But, you can start by investigating to know where you are going with it.

Jerry G.

Posted on Apr 28, 2008


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