Subwoofer quandaries... (1 Viewer)

[Edison Tinker]

Please bear with me as I try to explain my quandary…

I have a JBL PB10 10” subwoofer that is barely over the 30 day return period…for some reason, yesterday while watching Blade II, about halfway through the movie the sub would act like it had lost it’s signal for a few seconds, shut off and then come back on…this mainly happened during quieter passages during the movie…I tried playing some of the scenes again today and the sub worked just fine throughout, no loss of signal or anything…could the amp have been implementing it’s protection?

Later today, while watching some TV, I noticed that the sub’s output was diminished…I tried different channels and different sources including DVD and CD…the sub’s output did not increase with a change of source…I powered everything down and did some really quick and rudimentary troubleshooting…I swapped out cables, no good…I tried various sources, no good…I made sure that phase switches, gain settings and receiver setting were all what they were supposed to be, same results…wondering if perhaps something was wrong with the driver in the sub, I opened it up…everything seemed kosher…I tried pushing on the cone of the sub to see if perhaps the voicecoil was damaged, it seemed fine, no indication of damage…I reassembled the woofer and plugged everything back in…that is where I’ve left things…I have no idea what exactly is wrong…is it the sub, the receiver, I’m at a loss…if anyone has any ideas feel free to chime in…

Thanks in advance…

Tinker

 

[Ned]

Does that sub have an auto-power on/off? It may be going to sleep when there is no bass signal for a few minutes. Usually you can remedy if by reducing the level on the sub and increasing the LFE output so that the signal it gets is "hotter". If it doesn't have the auto-power thing then the amp is probably faulty.