I have a nice home stereo with Infinity speakers. The other day I heard this low hum in the house. After walking around I located the sound, my Infinity subwoofer was humming. It’s worked fine for years, no changes to anything.
The main power to the reciever was off. I tried plugging it into another outlet on a different circut breaker thinking there was a interference in the house lines. No luck.
It’s wired from the right and left channels in the reciever to the sub then to each speaker. The reciever doesn’t have a direct subwoofer output. I wired it like the book said to. I checked all the wires and nothing is touching to make a short. Like I said it’s been fine for several years and now out of warranty.
Any ideas?
Turn it off, then disconnect the wiring from it. Turn it back on. Still humming?
If yes, there’s probably a fault inside the unit. If not, the fault lies outside. Try re-connecting the wiring between it and the stereo receiver, but disconnect them at the receiver. Humming this way would indicate the wiring is picking up interference. If the humming stops, the receiver may be at fault.
Tracking down hums can be a beast of a job. Ask me someday about the sub that was picking up the 30 Hz sync from a local TV station.
Is this a powered sub, or an unpowered sub?
Powered, it’s plugged into the wall with it’s own 110 line. That’s what I plugged into a different wall outlet to make sure that wasn’t where interference is coming from.
My quick guess would be in the power system. 60hz humming can and will drive someone with good ears nuts, heck it’d probably drive me nuts.
If it’s an external power supply (unlikely due to the power involved) try another one… otherwise, unless you’re really good with electronics, I’d take it back to the shop for repairs.
Okay, powered sub. Detach the input lines coming from the receiver, and see if it still hums. If it does, then there’s something up with the sub or electrical circuit. Since you’ve already tried plugging it into a different circuit, this would suggest the sub, most likely in the power supply. If it doesn’t hum with the input lines detached, then there’s something up with the input. Could be multiple things. Possibly interference being picked up by the lines. Is there excess line coiled up? Do they run parallel to 110v lines for any distance? Could be a ground loop. Are your sub and receiver plugged into the same circuit? Could be something going on with the receiver, though not real likely if the sub hums when it’s off.
Hard to pinpoint from here, as there are lots and lots of possible sources for hum.