I have a hum in my Onix Rocket RS1000 speakers. They are driven by a 7100 except for the powered woofer which has its own amp. The hum disappears when I turn off the internal amp. It also disappears when I disconnect the speakers from the 7100. The hum appears when I connect the 7100 to the high level inputs on my SVS PB12-Plus/2.

Any thoughts? Is this a known issue with the 7100?

This does not sound like an issue with the 7100. It is most likely a ground loop hum caused by interaction with other components in the system (such as having the PB12 on a separate circuit from the 7100 if that is the case, or an improperly grounded cable service). Does the hum appear when the 7100 is connected to all of your speakers except for the SVS?

The hum occurs even when everything is turned off except the woofer in the RS1000. It's still there when everything is plugged into the same circuit. A cheater plug does not make a difference. The hum only comes from speakers that have an internal amp.

It does sound like a ground loop. BTW, there is no such thing as DC offset hum.

If it is a ground loop what can I do about it?

http://ubb.outlawaudio.com/ubb/ultimatebb.php?ubb=get_topic;f=6;t=000552

check this thread,see if this works,first time trying a link

did this fix your fault problem???
Bill

I didn't fix it but I did reduce it significantly by jumpering 2 of the connections on the powered amps on my speakers. I still have some hum.

you never have said if you have sat tv or catv.

if you do,just for giggles disconnect it.

I have CATV. Disconnecting the CATV made no difference.