# JBL Sub 135 Issue



## CXF

Hello all,
I recently hooked up my 5.1 surround sound to my television so that I could both listen to music through the speakers and play games with good audio quality. After testing all of the speakers and the subwoofer and connecting them to my Sony STR-DE595 receiver all was well. The sounds were pretty good for a first time home theater set up and I was pleased. Until I noticed that every time my subwoofer turned on t would go through a sort of "warm up" period where it would make a constant and loud thumping noise. Usually to a regular rhythm almost like "thu-thump" for about one to four minutes, before hitting a final very quick constant thumping and than would play just fine. Instead of that minor problem it works fine and normally I would be perfectly happy with the subwoofer except I just want to make sure it is not being damaged or will not get worse. Has anyone else experienced this problem before? If so how did you fix it? 
Just to restate the subwoofer is a JBL Sub 135, a big one at that with a built in amp.
Thank you all for the help.
- CXF


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## yustr

Welcome to TSF :wave:

THESE GUYS are saying its a bad solder connection inside the sub - on one of the amp boards. But before I opened it up, I'd make sure that there are no loose cable connections, that there's no EF interference from power cords laying on top of or under the cables from the receiver, that the output of the receiver is set up correctly. Try plugging it into a different outlet - one on a different circuit breaker from the other components or any motors (refrigerator, etc...) 

Good luck.


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## CXF

Hey,
Thanks, I actually saw that board post but was unsure if it was directly my problem or not. I will open it up on a surface away from other cords and things eventually. What else could I connect the sub to to test it? I do not have another receiver nor no anyone around me who does. Also, I do not know if this matters but the way I am connecting it to my receiver is through the LFE port on the back with a double sided RC cable that is meant for car audio systems, it seems to work fine though.


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## yustr

I don't know of any way to test a sub without a receiver to send it a signal. The way you've got it hooked up sounds fine. A cable's a cable - all do the same thing. When I said away from other cords I meant while it's operating it should be free from interference that might come from the power cords of other equipment or appliances. But, it sounds like you're going to have to open it and see if there's a burnt connection. :upset:


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## CXF

So, I followed the instructions posted on that site and removed some of the loose brown glue. Unfortunately it did not fix the problem. Should I try to strip off every bit of the glue touching that particular circuit board? Thanks again.


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