Need help with Woofer problem

[marvontherim]

I have a JBL PB10 sub woofer and when I plug it in I get a loud piston type thumping sound. I can only stop it by unpluging it. Can anyone tell me what that is and how to stop it.
thanks

 

[Johnd]

It could be a number of things. Blown speaker, blown amp, improper connections, interference, etc.

I would first:
1) turn down all power levels (both the receiver's master level and it's sub level, as well as the volume control and boundary gain on the sub to low levels),
2) unplug all sub connections and ascertain that they are correct and in good condition.

Then see if you still have the same problem. if you do, it would be either the speaker itself or it's amp. Do this and let us know what happens.

It would also be helpful if you list the receiver model and the connections that you are using, as well as the settings on the sub and receiver if you still have a problem after doing the "tune up" above. Cheers.

 

[JennAir]

Pretty freaky when an audio component develops it's own heartbeat.

 

[marvontherim]

Thank you Johnd,

The sub is totally disconnected from the reciever. I just plug it in and it goes crazy.
My amplifer is a Sony STR-G1ES reciever.
Thanks again

 

[Johnd]

If the only connection to the sub is the power cord (assuming the cord and connections are in good order), and "it is going crazy", your sub's amp is blown.