What the... my subwoofer keeps humming!?! (1 Viewer)

[Inspector Hammer!]

O.k., hopfully you guys can help me out here, I have a 'Jensen SW-1000' sub connected by an 'Acoustic Research' audio cable into my 'Technics SA-DX930' DD and DTS reciever, snd every so often, for no reason, my sub will just kick on and a distinct low-level hum will sound from it!?! The only way to stop this sound is to switch off the sub, then turn it back on again. But the sound returns at a later date and time unexpectedly. I've had this sub for almost two years now with no trouble.
I though of two things that may be the problem...
1. The 'Acoustic Research' cable I bought is defective in some way or...
2. I'm recieving some sort of transiant signal from my reciever causing my sub to kick on and hum (i keep the sub in 'standby' mode).
What do you think, is it time for a new sub, or will a cable replacment do the trick?
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"How can I heal, when I can't feel time?"
Leonard from Memento

 

[Phil A]

Sounds like 60 Cycle (HZ) hum kicking in perhaps when some combination of equipment may be on. You should look to see if there is any pattern of the hum when certain things are turned on, see if any of the plugs to your equipment are non-polarized and reversible, it could be the electrical receptacle a $2.97 Leviton commercial grade one at Home Depot would not hurt anything. When certain stuff is on it may be creating a ground loop - if your sub or any of your equipment has 3 prong plugs you can try $ 0.45 3 to 2 prong adapters at Home Depot.

 

[Inspector Hammer!]

Hmmm, I really don't think that's the problem, i've had my system hooked up the same way for about a year with no trouble until recently. I first heard the hum about 4 weeks ago i'd say.
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"How can I heal, when I can't feel time?"
Leonard from Memento

 

[Nick G]

Per a suggestion from HSU, a three into cheater plug from RS placed on the sub power cord cured an intermitent hum from my HSU VFT2. Something about ground loop they said. Anyway the sub works fine now.
Regards, Nick

 

[Keith Mickunas]

John, give the cheater plug a try. If that solves the problem then that will at least point it out. I don't know enough about electronics to say whether or not a ground loop hum can suddenly appear, or if the symptoms can be intermittent. In mine if I have the cable TV connected and the sub plugged in I immediately get the hum, and it stays, but the cheater plug solves the problem. Perhaps something in your system or outlet has come disconnnected and the ground is messed up. Also check to see if the hum occurs when some appliance or maybe a light with a dimmer is on, something like that. This could potentially be a symptom of a larger problem and at least the cheater plug will give you some idea.