subwoofer humming

[peterpolka]

hey guys i am new to any forums but i am so frustrated with my sub humming i am breaking down and putting up a post
the sub does work but even after the receiver is turned off it keeps humming and i find it annoying
the sub is a paradigm pdr-10 v.4
the sub is about three yrs old but can't find the receipt from when i purchased it and the place i bought it from has changed owners and they cant seem to find it
have tried some basic troubleshooting.
• Changed the power source. (switched outlets)
• Changed subwoofer cable
• Ensured ‘sub’ on A/V receiver wasn’t turned off
• shielded the sub cable with wire loom

when in the off position there is no humming
in standby it does hum

[ScaryBob]

in standby it does hum

That sounds like a bad capacitor in the power supply. I had a Paradigm amp do this after less than a year. It is probably fixable but would likely cost well over $100. If you want to DIY, new caps are probably available on eBay. I decided to trade it in on a better sub. I would never buy a Paradigm sub again.

[57]

Does it hum with the sub cable connected? Disconnect to see if it's the cable (Yes I see you changed it but...)

[ScaryBob]

A ground loop is possible but it's unlikely to cause hum in standby. Follow 57's advice to check for a ground loop. To prevent a ground loop, the sub and amp should be plugged into a common outlet.

[Danster]

Like 57 said, I had a sub that would humm and never turn itself off or go standby mode. I replaced the RCA cable for a better quality and the hum disappeared. Doesn't take much to make it humm I guess.

[merve04]

I too recently had this problem, when I turned my side lamps on, the sub would turn on and and start humming, turn the lights off, sound goes away. Being in the cable business, I took a 20' piece of RG6 and put some RCA compression ends. Problem solved.

[peterpolka]

with the cable out it still hummed
i was watching a movie today and paused it
the sub went into standby and hummed like crazy

[Danster]

Take the sub and plug it in a different circuit and see if it humms. There might be something wrong with your house cabling if it doesn't show up in a different area.

[jimha]

have had the same problem on and off for years with a Paradigm Servo 15 v.1 - never shuts off and sounds like a badly tuned radio if you stick your ear up to it sometimes. Problem is sub cable is in ceiling and wall. Sub is also in fixed position and can't be moved. I did ground outer layer of sub cable and that improves it but does not fix it.

[caper_26]

Try a "cheater" plug (3 to 2). Not saying you should use this for regular use, just as a tool to trouble shoot. If it fixes your problem, you have a ground loop in the power supply of your house. Otherwise, you have a bad component on your plate amp. I have 2 subs, with both of the aforementioned problems. The cheater plug works to "fix" one, and the other needs a new plate amp. It hums with only the power cable plugged in, and no source.

[jimha]

thanks - will definately try that.

[jimha]

finally solved my problem - feel like an idiot for not trying this ages ago. To isolate the problem (with no source playing even with the receiver turned off the sub was picking up what sounded like Charlie Brown's teacher ie sounded like a muffled badly tuned radio) I worked my way up from the sub on its own and then hooking it up etc. Turns out its the Paradigm X-30 sub control box that is the culprit. When I plugged the sub directly into the receiver - problem solved.