I basically shut off my reciever and TV and the woofer still making a bit of a humming noise out of the woofer, YOu have to put your ears next to it to really hear it....

that happens to me aswell, i think ive read it has something to do with the ground wire.

Well does that really matter then? Do i need to fix it?

HUM FAQ

http://www.avsforum.com/avs-vb/showthread.php?t=322698

My woofer is making a hum noise when I close my system....but the noise doesn't stay on after 15 mins or so. The thing is, Im still hearing noise from my subwoofer even though my system is shut off. My subwoofer is on auto on/off, so after 15 mins or so, you won't hear it
I think think ground looping has anything to do with it


does this affect quality or perfomance while playing movies though?

I't not a big deal making small noises after for 15 mins anyway since I have to be close to listen to it.

Jesse40902,

Your subwoofer is probably doing exactly what it is supposed to be doing. Many components have a "noise floor" that in typical use cause nothing objectionable. You would only be having a problem if the sub turns on all by itself throughout the day and night, and made thumping noises doing it. I've had a client who was convinced his house was haunted!

The reason some auto-on subs turn on seemingly at random is that they are set sensitive, which is nice if you are playing low level material. They can also get small signals from an amp that is turned off, because some receivers and processors go into UNDEFINED OPERATION when turned off. As the power supply circuits settle to zero, the low output impedance of the pre-amp level subwoofer output can go very high instead. This converts your (possibly very long) subwoofer signal cable and some of the parts inside the powered down component into an ANTENNA. Every once in a while enough signal can come along and turn on the sub. Its annoying, but in most cases not dangerous for you or the equipment.

I teach installers how to build a relay "hush" circuit. It essentially uses the switched power outlets on a receiver to turn a relay on and off with the piece of gear. You run the sub line through the relay, so that when the receiver is OFF, the relay switches away from the sub output, and shorts the pin and ground of the RCA together. Your sub will NEVER turn on randomly again. It would however, still run its proscribed shutdown delay, which it sounds like is 15 minutes.

I'll repeat that in your case, Jesse, your auto-on system is working 100% correctly. One way to see if the line is picking up the hum is to have nothing connected. just unplug all wires from the sub, and if it hums the same, its just the sub...

Martin

I've had a client who was convinced his house was haunted!

:D

Sorry, couldn't resist.

Jesse,

I suspect that you are, in fact, experiencing a ground loop problem, and the HUM FAQ linked to above could hold the answer.

Craig