Hum coming from surround sound speaker

[mystang52]

I have a 12 year old surround sound system. It's a Kenwood, not top of the line but if I recall not bottom end either. Anyway, one of the front speakers is now emitting a hum, almost constantly.
Is this likely just a defective speaker or is it time to replace the whole unit?

[BBQ-Nut]

Can you swap the front speakers to isolate the problem with either the speaker or the receiver?

[Big_Hitter]

agreed, try swapping the speaker, one reason you can get a hum is that the polarity is messed up, or it could be the receiver - you can get a nice, new 5.1 receiver for under $300 - I wouldn't bother trying to get it repaired

[RunningBum]

^^ good idea to try to isolate the problem. Also do you have anything new (powered) near the area that could be causing electrical interference? Is is possible to move the whole system to use an outlet on a different breaker?

[M Paquette]

A common source of hum on one channel is a poor input connection shield. The old RCA "phono plug" connectors are very prone to this problem.

Try wiggling the connectors for the channel with hum at both the back of the amplifier and at the audio source. If the hum cuts in and out, replace that cable.

[BBQ-Nut]

Quote:

Originally Posted by M Paquette A common source of hum on one channel is a poor input connection shield. The old RCA "phono plug" connectors are very prone to this problem. Try wiggling the connectors for the channel with hum at both the back of the amplifier and at the audio source. If the hum cuts in and out, replace that cable.

Good point.

Next thing to ask/check is if the hum is present on all input sources (bluray, dvd, cd, tt, etc) or just one source.

If all, and not the speaker then the receiver is the most probable culprit.

If just one input source is causing the hum, could be the cable from that device or the device itself.

[mystang52]

It's worse than I thought! I was mistaken. That hum is coming from all 5 speakers. New receiver needed? I disconnected and reconnected all of the plugs and wires, and no change.

[BBQ-Nut]

Quote:

Originally Posted by mystang52 It's worse than I thought! I was mistaken. That hum is coming from all 5 speakers. New receiver needed? I disconnected and reconnected all of the plugs and wires, and no change.

Do you get the hum when all the input sources (cable box, cd, tt, etc) are turned off and just the receiver is on?

[sengsational]

Sometimes as a power supply gets older, it develops a "ripple" and that gets through as a 60 cycle hum. If that's the case, not much you can do.

Some of the suggestions above might work, might not. My suggestion would be to make sure you've got a solid ground on every bit of equipment electrically connected together. Pulling inputs one at a time sounds like a good idea. Keep removing connections until only the power and speakers are connected.

[MichaelB]

Quote:

Originally Posted by sengsational Some of the suggestions above might work, might not. My suggestion would be to make sure you've got a solid ground on every bit of equipment electrically connected together. Pulling inputs one at a time sounds like a good idea. Keep removing connections until only the power and speakers are connected.

No or bad ground is probably biggest cause of speaker hum. That, and the cable TV connection. I would disconnect and unplug all the inputs and listen. If you still hear it, the source is either the receiver or the ground. Otherwise, reconnect the inputs, one at a time, testing each time. Leave the cable for last.

[HFWR]

It hums because it doesn't know the words...

If cables and such check out, might be a bad capacitor in the power supply.

Then again, I bought a new Sony surround receiver recently for $300. Features include bluetooth and Airdrop/Airplay.

[Big_Hitter]

Quote:

Originally Posted by mystang52 It's worse than I thought! I was mistaken. That hum is coming from all 5 speakers. New receiver needed? I disconnected and reconnected all of the plugs and wires, and no change.

time for an upgrade - I vote Yamaha - I've got this one and love it


http://www.amazon.com/Yamaha-5-1-Cha...eceiver+stereo

[mystang52]

Thanks all. Had to leave for a while. I will tackle these suggestions, again, tomorrow and report back.

[target2019]

I would eliminate the power strip, if one is present. Also look at lighting that might be on that power leg. Other suggestions sound good. Might buy that yamaha...

[JoeWras]

I found one of my inputs was causing hum. I put a ground loop isolator on it.

You can search "audio ground loop isolator".

Don't "wish the fix", though. Find the culprit before buying anything.

My problem was I had my computer hooked to the audio receiver in order to play between the two. Both were on different plugs, same circuit. But that was enough to cause some ground loop hum.

[Walt34]

Not likely, but I had one hum because it resonated (harmonic?) with the bookcase that it was sitting on. Set the speaker on the carpeted floor and all was well.

[HFWR]

Quote:

Originally Posted by HFWR It hums because it doesn't know the words... If cables and such check out, might be a bad capacitor in the power supply. Then again, I bought a new Sony surround receiver recently for $300. Features include bluetooth and Airdrop/Airplay.

One second thought, if the power supply was passing a/c, i.e. a bad filter cap, it would likely affect all speakers.

[gauss]

Quote:

Originally Posted by HFWR One second thought, if the power supply was passing a/c, i.e. a bad filter cap, it would likely affect all speakers.

This is what came to mind for me. Could be a $0.99 capacitor or a solder joint that has opened up.

If you don't end up repairing it you may wish to sell it on ebay. For the right price someone will take the project on.

-gauss

[mystang52]

I sincerely appreciate all of this helpful advice. But I had a choice of trying the various suggestions or doing a whole bunch of fun things (including going for a nice long run).
I disconnected the subwoofer and that reduced the sound of the hum. Have a busy weekend coming up, so I won't tackle this until Monday.
I gotta confess, though, I'm sorely tempted to just buy a new system. Then again, DW is the greater skinflint of the two of us, so before she'd approve she'd ask me if I tried to fix it first. I could lie to her and say I did, but I think I'll try the suggestions here, first.

[mpeirce]

[QUOTE=mystang52;1671491
I disconnected the subwoofer and that reduced the sound of the hum. Have a busy weekend coming up, so I won't tackle this until Monday. [/QUOTE]

When my subwoofer started noticeably humming, I unhooked it too - about 3 years ago.

Can't say I really miss the bass that much, which why it's still just sitting there...