Topic: my Sub has a humming sound....

[Sterling]

My sub hums. It has for a while now but its pissing me off..I have it connected line level from my amp with a cheap RCA cable. ~ This is probably my problem, will a shielded cable help this? Maybe I'll pick one up on the way home today...

[Daryan]

It's either a grounding problem, or a rfi/emi problem if I were to guess.

[Sterling]

It's either a grounding problem, or a rfi/emi problem if I were to guess.

rfi/emi  Any solution ideas? 

[zowie]

My sub hums. It has for a while now but its pissing me off.

Could be it doesn't know the words.

[eric.B]

My sub hums. It has for a while now but its pissing me off.

Could be it doesn't know the words.

 

[pfife]

My sub hums. It has for a while now but its pissing me off.

Could be it doesn't know the words.

That's really bad.  Terrible.

+T

[Sterling]

My sub hums. It has for a while now but its pissing me off.

Could be it doesn't know the words.

 

[dnsacks]

does the humming subside if you unplug the rca?

does the sub have a 3 prong AC plug?

If the humming subsides when you unplug the rca and the sub has a 3 prong ac plug (and another piece of gear in your playback system also has a 3 prong ac plug), try using a "cheater plug" (3 prong>2 prong adaptor) on the sub's ac plug and see if the humming goes away.  If so, you had a ground loop problem.

[Zee]

My sub hums. It has for a while now but its pissing me off..I have it connected line level from my amp with a cheap RCA cable. ~ This is probably my problem, will a shielded cable help this? Maybe I'll pick one up on the way home today...

Just unplug it from the wall you dont need a sub

[Sterling]

does the humming subside if you unplug the rca?

does the sub have a 3 prong AC plug?

If the humming subsides when you unplug the rca and the sub has a 3 prong ac plug (and another piece of gear in your playback system also has a 3 prong ac plug), try using a "cheater plug" (3 prong>2 prong adaptor) on the sub's ac plug and see if the humming goes away.  If so, you had a ground loop problem.

It does not humm when I unplug the rca...which is a crappy cable...I will try the power cable thing too...and

My sub hums. It has for a while now but its pissing me off..I have it connected line level from my amp with a cheap RCA cable. ~ This is probably my problem, will a shielded cable help this? Maybe I'll pick one up on the way home today...

Just unplug it from the wall you dont need a sub

I like the bass. I have cerwin vega avr632's now (this is my surround system) and the sub really helps deliver the "feel" of the movie...

[scervin]

Could be grounding problem on the amp/receiver side.  Start unplugging devices from the receiver until it goes away. If it doesn't, then it is probably a grounding issue on the receiver.  Try a different cable ass well, but I doubt this is the problem.

sc

[Tim]

what kind of sub?

some of the paradigm's pdr series hum very badly. mine, thankfully, does not

[Sterling]

Ok its a cerwin vega sub (avs 632; 100w powered) and its not just humming...its screaming! I can't even turn up the volume only but a tick and this thing takes the pictures off the walls. I cannot use it at all...I tried unplugging the components from the receiver (HK avr100), directly plugging the sub into the wall, using one of those "cheater plugs", I've also tried using different rca cables too...no luck.

I'm trying to hook it direct line level from my receiver...

[jpschust]

what happens when you plug it directly into the wall with nothing being fed into it?  especially when you turn up the volume on the sub?  anything there?

[pickmando]

Can you use a speaker level to send signal to the subwoofer instead of line level?  Does that make any difference?

[Sterling]

what happens when you plug it directly into the wall with nothing being fed into it?  especially when you turn up the volume on the sub?  anything there?

Nothing there...only when I plug in the live level.

Can you use a speaker level to send signal to the subwoofer instead of line level?  Does that make any difference?

I could use that but what speaker level would I put into it? All of them? Thats a pain in the ass but maybe the only way...the speaker level connections are for both front channels...

[krebsy]

Do you have a Cable TV signal coming into your system? I recently switched to a new amp, and I had a nasty hum problem crop up. After lots of seaching/reading I learned that a catv wire can lead to ground loops. As soon as I disconnected the Cable TV feed from my VCR, no hum.

[dnsacks]

when you tried the cheater plug, did you plug it into the top plug in the outlet or the bottom plug in the outlet?

This sounds a LOT like ground loop problem -- which is where 2 different grounded devices (your sub amp and another piece of gear) are both grounded and the hum is between the 2 grounded devices.  If you plugged the cheater plug into the top outlet, the metal ring on the bottom of the cheater plug would be touching the screw in the middle of the outlet and would be grounding the sub through the screw.  Plugging the cheater plug into the bottom plug should keep this from happening. 

When the sub is grounded, attaching the rca cable (or any cable) to the rest of your gear would cause it to share the ground with other devices and the hum would be back.

do any other devices in your audo system use 3 pronged plugs?

[Sterling]

when you tried the cheater plug, did you plug it into the top plug in the outlet or the bottom plug in the outlet?

The bottom plug.

do any other devices in your audo system use 3 pronged plugs?

No

I should perhaps be more clear about this hum...its actually house shaking! I can't turn the volume up on the sub at all when its attached via rca plug through the direct line, regardless of how its plugged into the wall.

I'm going to try and run it through the speaker wire level to see if that helps, in addition to using the cheater plug as well. I just thought it would so much easier to run one rca cable than both front channels from receiver to sub to speaker...

[Sterling]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

[Genghis Cougar Mellen Khan]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

Oktava 012 >>>> V3 >>>>Hosa ODL 276 >>>> JB3@44.1 >>>>wavelab 4.0

With your signature, I was thinking it could be an extra long cable run... 

Glad you got it figured out. 

[Sterling]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

Oktava 012 >>>> V3 >>>>Hosa ODL 276 >>>> JB3@44.1 >>>>wavelab 4.0

With your signature, I was thinking it could be an extra long cable run...