Fluxed up

[supermotrad]

I am having a wierd problem with my center channel speakers, using totem mights, huming when my recessed lights are on. They do not run on low voltage, they are quartz 50w. They only hum when the lights are on, and there are 2 seperate circuits for the lights also, and it hums when either set is on?? The speaker wires are good 12 or 14 gauge and do not cross over any power lines. There are power lines in the walls behind them, but one set of lights in the ceiling are on a whole other circuit for sure and it does it. The speakers are on a shelf, next to the wall. What can I do to fix this. I hope it's not hurting my reciever in any way, power being induced into the circuit.

 

[MDS]

Flourescent lights and dimmer switches are notorious for causing the kind of hum problem you describe.

Probably the best you could do to fix the problem is ensure that the receiver is plugged into an outlet that is on a different branch circuit than the lights. This is also the type of problem that could actually be solved using a power conditioner.

 

[supermotrad]

Wait, here is the weird part I'm talking about, the AVR is not plugged in either, I have a conditioner on it also, I can turn the whole power outlet down, and it CENTERS ONLY still hums when the lights are on. The wires to the speakers must be getting induced. But from romex inside the wall behind them?

 

[MDS]

Maybe the buzz/hum from the lights is being picked up directly from the air by the speaker, so the speaker sounds like it is buzzing because it is moving in response to the frequency of the light buzzing.

Strange problem and the first I've heard of a such a thing.

 

[jcPanny]

Light buzz

It is doubtful that a couple ceiling lights are generating enough EMI to induce a current in your speaker cables. If this was the case, then Cell phones, wireless networking, and pacemakers would not function in your room with the lights on.

The cheap florescent lights in my garage make a buzz sound. I would check it all of the lights or a bad bulb is making the buzz sound as opposed to the speakers.

 

[supermotrad]

found it GAUSS

Here is the deal. I disconnected the speaker wire from the terminals, these are Totum Mights BTW, and with the wires off it still does it! I carried the speaker around and you can here the hum by the wall with the wires feeding the can lights, REALLY loud. There is 8 50w halogen cans on each circuit, if I carry the speaker over to the wall with the dimmer and hold it by the wall, it hums pretty friggin loud. I have a gauss meter, and it reads 2.75 miligauss at the switc, or .5 mW/cm2. I don't mind the hum as far as a distraction is concerned, it can't be heard unless there is no ambient sound and you are next to the drivers. However, I hope that is not going to give my Yamaha 2700 some wierd signals into it, and hurt it over time? I wonder if they were not on a dimmer, if the EMFs would be less.
CRAZY

 

[jcPanny]

Dimmer switch

Stand next to the dimmer without the speaker. I bet the buzz will be just as loud.

Cheap dimmers operate by chopping off part of the AC waveform creating electrical noise (on the AC power line). Consider replacing the dimmer with a higher quality one and running your A/V gear off of a different circuit then the lighting.