Intermittent Subwoofer Hum

[t3steve]

I have an intermittent subwoofer hum that I can't find. It only seems to happen when the system is turned off, I'll come home or be woken up in the middle of the night by it. It doesn't happen very often though

System consist of:
Plasma tv plug into wall, three prong plug

plugged into power strip/conditioner:
Yamaha HTR 6080 receiver
DVD player
Direct TV Satellite DVR
Wii

powered sub, plugged into wall two prong plug

originally the power strip had a three prong plug, I cut off the ground pin and no difference in the hum problem.

I just recently replaced the subwoofer with no difference in the hum problem

Could the reciever have an internal problem that could cause this?

Any other thoughts or suggestions?

 

[walter duque]

Is there anything else that runs of that same circuit. Florecent Light or any kind of appliance? Did you try a different circuit?

 

[agarwalro]

I have an intermittent subwoofer hum that I can't find. It only seems to happen when the system is turned off, I'll come home or be woken up in the middle of the night by it.

Maybe it is Crash Test Dummies - Mmm Mmm Mmm Mmm

What is really odd is that your sub has a 2 pin power cord (aka, no ground) yet the hum is coming only from the sub. This makes me believe that it may not be a ground loop hum. Maybe, the sub amp is developing a failure that is slowly building up. Maybe a fried cap. (shooting in the dark with the fried cap thing) If possible move the sub to a completely different circuit and see if the hum persists. If yes, then it is most likely internal to the sub.

Invest in this if you have reason to believe that it is a ground loop hum, http://www.zzounds.com/item--EBTHUMX

Though unlikely, maybe there is something on the same circuit that turns on and off, thereby intermittently completing the ground loop. Look for a space heater or fridge... Something that has auto power on-off type supply connection.

Since you are getting the hum only from the sub, the offending device should be on this circuit. Try the house panel, switching off breakers one at a time to determine which circuit it is. Once the circuit is identified, unplug devices one at a time to determine which device is offending.

I just recently replaced the subwoofer with no difference in the hum problem

I know it is CTD now!

If your sub has a auto signal sense setting, does it say in the "active" state or does it go into standby and still hum?

 

[sawzalot]

I have an intermittent subwoofer hum that I can't find. It only seems to happen when the system is turned off, I'll come home or be woken up in the middle of the night by it. It doesn't happen very often though

System consist of:
Plasma tv plug into wall, three prong plug

plugged into power strip/conditioner:
Yamaha HTR 6080 receiver
DVD player
Direct TV Satellite DVR
Wii

powered sub, plugged into wall two prong plug

originally the power strip had a three prong plug, I cut off the ground pin and no difference in the hum problem.

I just recently replaced the subwoofer with no difference in the hum problem

Could the reciever have an internal problem that could cause this?

Any other thoughts or suggestions?

The only hum I ever had in my subs came from the digital converter box try taking out the DTV box and see what happens.I assume you have the audio going to your rec. via RCA or Toslink.disconnect it and see if it helps.

 

[lsiberian]

I have an intermittent subwoofer hum that I can't find. It only seems to happen when the system is turned off, I'll come home or be woken up in the middle of the night by it. It doesn't happen very often though

System consist of:
Plasma tv plug into wall, three prong plug

plugged into power strip/conditioner:
Yamaha HTR 6080 receiver
DVD player
Direct TV Satellite DVR
Wii

powered sub, plugged into wall two prong plug

originally the power strip had a three prong plug, I cut off the ground pin and no difference in the hum problem.

I just recently replaced the subwoofer with no difference in the hum problem

Could the reciever have an internal problem that could cause this?

Any other thoughts or suggestions?

Um you cut the ground pin? Do you want to have fires or get electrocuted?

You need a ground on your equipment immediately.

Then plug the sub into the same network as the receiver. you want to create a star topology with a single point entry for all your audio equipment.

 

[t3steve]

If your sub has a auto signal sense setting, does it say in the "active" state or does it go into standby and still hum?

It goes into active

 

[t3steve]

The only hum I ever had in my subs came from the digital converter box try taking out the DTV box and see what happens.I assume you have the audio going to your rec. via RCA or Toslink.disconnect it and see if it helps.

The next time it happens I will try disconnecting the DTV Satellite box

 

[t3steve]

Um you cut the ground pin? Do you want to have fires or get electrocuted?

You need a ground on your equipment immediately.

Then plug the sub into the same network as the receiver. you want to create a star topology with a single point entry for all your audio equipment.

I tried that for a while and I still got the hum

 

[t3steve]

Is there anything else that runs of that same circuit. Florecent Light or any kind of appliance? Did you try a different circuit?

sometimes it happens in the middle of the night when everything is off and the electrical circuit is outlets only, no appliances

 

[just-some-guy]

i don't leave any of my gear on.

 

[t3steve]

i don't leave any of my gear on.

It's not left on, something trips the auto on the subwoofer and then induces a hum

 

[just-some-guy]

It's not left on, something trips the auto on the subwoofer and then induces a hum

partially on, is still on.

but, if i had your problem. i would disconnect the rca's at the reciever = see if it does it. then at the sub = see if it does it. etc.

 

[agarwalro]

It goes into active

i would disconnect the rca's at the reciever = see if it does it. then at the sub = see if it does it. etc.

Good suggestion. Since it may be easier to get to the back of the sub, than the receiver (definitely easier to reconnect it) try the sub end first.

If the sub still hums when there is no audio cable connected to it, the sub amp is the culpret.

 

[t3steve]

partially on, is still on.

but, if i had your problem. i would disconnect the rca's at the reciever = see if it does it. then at the sub = see if it does it. etc.

I did that a while ago and it stops the hum