Humming From Sub.

[CRIMSON PEARL]

Similar question asked by someone else, hope it is not redundant.

Just finished the last connection on my system. Connected sub the same way it used to be with my new Yam 2700 sub pre out. The reciever MASTER power ON or OFF HUMMing from sub ONLY when plugged into reciever or anything else. Level on sub doesn't matter. I reversed the cable (and tried another) and the same thing. It happens when the audio cable is plugged into the input OR OUTPUT of sub as long as the other end is also connected to something. Tried UNPLUGGING all power cords exept sub. Still happens when audio cable is connected.

I'm afraid sub was damaged in move.

 

[Jack Hammer]

Similar question asked by someone else, hope it is not redundant.

Just finished the last connection on my system. Connected sub the same way it used to be with my new Yam 2700 sub pre out. The reciever MASTER power ON or OFF HUMMing from sub ONLY when plugged into reciever or anything else. Level on sub doesn't matter. I reversed the cable (and tried another) and the same thing. It happens when the audio cable is plugged into the input OR OUTPUT of sub as long as the other end is also connected to something. Tried UNPLUGGING all power cords exept sub. Still happens when audio cable is connected.

I'm afraid sub was damaged in move.

Sounds like a short. Do you have a different reciever you can try plugging the sub into?

 

[CRIMSON PEARL]

Sounds like a short. Do you have a different reciever you can try plugging the sub into?

My old one. BUT I connected the sub to a different component earlier, still hum. Also using pre out on the 2700 to my power amp NO HUM fron other speakers.

I did a test. Connected sub to cd changer. Changer has video connection into tv for on screen display. Disconnected video connection to tv NO HUM, connected has hum. Plugged back into reciever STILL hum. Possibly bad video connection (shielding) someware in setup. I don't know.

I have to go to work now, I'll troublshoot more tomorow.

 

[CRIMSON PEARL]

Update; The coaxal line running INTO the cable box is the cause. I have to call the cable company now.

 

[Mr. Lamb Fries]

Had the same problem a few weeks ago...tried ALL the suggestions from this site. he hum finally stopped when I ran the coax from the wall, through my surge protector, then to my cable box. If you haven't, try this and see if it helps.

 

[MDS]

Update; The coaxal line running INTO the cable box is the cause. I have to call the cable company now.

It's a ground loop and the cable is nearly always the cause. Make sure the cable company checks the ground where your service enters your house.

If you still have the problem even after making sure the cable is grounded properly, you could buy an isolation transformer (about $50 for a 'good' one).

 

[zumbo]

The reciever MASTER power ON or OFF HUMMing from sub ONLY when plugged into reciever

DO NOT plug the sub power cord into the receiver. EVER!

 

[CRIMSON PEARL]

The cable guy grounded the line where it comes into the house and replaced the box with one with HDMI outputs. It did nothing. I'm going to buy a grounding adapter at radio shack later and try to ground it near the box.

If that doesn't work I'll remove about an inch of the ground from the coaxel wire which should solve the problem without ordering anything. What are possible negetives of doing this.

 

[TLS Guy]

The cable guy grounded the line where it comes into the house and replaced the box with one with HDMI outputs. It did nothing. I'm going to buy a grounding adapter at radio shack later and try to ground it near the box.

If that doesn't work I'll remove about an inch of the ground from the coaxel wire which should solve the problem without ordering anything. What are possible negetives of doing this.

Then you won't have a proper connection. Your system needs ONE ground only. You need a ground isolator on you cable line. That is what you need to do.

 

[CRIMSON PEARL]

Then you won't have a proper connection. Your system needs ONE ground only. You need a ground isolator on you cable line. That is what you need to do.

I bought a $4 coaxal grounding block from radio shack. Grounded line to sub body. WORKS perfect. Thanks.