How I solved my grounding hum

[sascuderi]

Thought I'd pass this solution along.

Have a new sub and had the grounding hum. Sub was connected to receiver from the receiver's subwoofer output (LFE) by a sheilded RCA cable. Receiver cross-over set to 80 and the sub's cross over disabled. (as per instrutions that came with the sub and from what I have read online)

Had the hum, which I temporarily resolved by using a cheater plug on the 3 prong sub's plug. (From what I understand, this confirms the hum is from a grounding loop. Removed the cheater plug since not a safe solution)

Here is how I solved the hum. I turned the cross-over circuits in the sub back on. Set it to the highest setting (160) and hum is gone!!

I figure since the receiver is set to a cross-over of 80, having the sub set to 160 should make no difference. Right?

Anyone know why this would resolve a grounding hum?


ps never knew what I was missing without a sub. All I can say is..... Wow

 

[mtrycrafts]

Here is how I solved the hum. I turned the cross-over circuits in the sub back on. Set it to the highest setting (160) and hum is gone!!

I figure since the receiver is set to a cross-over of 80, having the sub set to 160 should make no difference. Right?
Anyone know why this would resolve a grounding hum?

No problem at all having that crossover on and that frequency, or, even lower as it would cut off any higher frequency to the sub at a steeper rate.
Not sure what that being on helps.

 

[jcPanny]

Ground Hum

Interesting results.
I sounds like your noise source is over 160 Hz and the sub crossover is filtering it out. Most of the time, the noise is the 60 Hz AC power so I high crossover setting would not help much.

 

[sCiEnT]

I also notice a hmm on my friends sub when we first hooked it up. I isolated it to the the incoming cable tv line. I got around this by passing it thru the monster power line filter that we had. Plugged in the cable to the monster surge suppressor unit and plugged in the output of that to the cable box. The humm was gone.