HK subwoofer hum

[vranic83]

Hi, i have a question regarding a HK subwoofer.

After having connected the subwoofer to the amp using the a none shielded audio cable i have no problems, but when connecting a shielded cable I get a loud hum. I am 99% sure that there isnt anything wrong with the cable, so I am wondering if there is anything else that could cause the hum with a shielded cable, but not with a normal one?

Thanx

 

[TLS Guy]

Hi, i have a question regarding a HK subwoofer.

After having connected the subwoofer to the amp using the a none shielded audio cable i have no problems, but when connecting a shielded cable I get a loud hum. I am 99% sure that there isnt anything wrong with the cable, so I am wondering if there is anything else that could cause the hum with a shielded cable, but not with a normal one?

Thanx

Sounds like a ground loop. Disconnect your satellite, or cable box from your receiver and see if you still have hum. If you have hum still as a test, put a ground break on your sub AC connector and see if you still have hum.

 

[T2T]

I had a similar issue with my setup. H/K receiver, sub by another manufacturer and a shielded cable. I traced my issue down to the video cable that ran between the monitor "out" on the back of the receiver and my LCD tv. Of course, when I disconnected the cable, I lost my ability for the OSD functions of the receiver - but, the hum was gone.

Fortunately, with the OSD, I don't need it very often - just when doing an initial calibration and any additional updates. When those happen, I just reconnect the cable for a few minutes. I've tested several other video cables - none of which would resolve the issue.

 

[TLS Guy]

I had a similar issue with my setup. H/K receiver, sub by another manufacturer and a shielded cable. I traced my issue down to the video cable that ran between the monitor "out" on the back of the receiver and my LCD tv. Of course, when I disconnected the cable, I lost my ability for the OSD functions of the receiver - but, the hum was gone.

Fortunately, with the OSD, I don't need it very often - just when doing an initial calibration and any additional updates. When those happen, I just reconnect the cable for a few minutes. I've tested several other video cables - none of which would resolve the issue.

The issue is not the cable. Your receiver and TV have a potential between ground, creating the earth loop. Try putting a ground break on your TV for a test and see if that solves it, I bet it will. Then make sure the TV and receiver have the same ground. If that does not solve it then you need to tell us if there is anything else plugged into the TV.

 

[mtrycrafts]

I had a similar issue with my setup. H/K receiver, sub by another manufacturer and a shielded cable. I traced my issue down to the video cable that ran between the monitor "out" on the back of the receiver and my LCD tv. Of course, when I disconnected the cable, I lost my ability for the OSD functions of the receiver - but, the hum was gone.

Fortunately, with the OSD, I don't need it very often - just when doing an initial calibration and any additional updates. When those happen, I just reconnect the cable for a few minutes. I've tested several other video cables - none of which would resolve the issue.

Do another test on that TV. Leave your receiver attached to the TV and just disconnect the cable TV feed at the wall, leave the 120V power to the Tv and see if it still hums. If not, there are ground isolators for the RF cable line, about $10.
http://www.cencom94.com/gpage.html8.html

 

[more power]

I have had the same problem,the preamp outputs on their receivers are the ground loop problem. I had 3 receivers with the same problem,h/k said there was no problem with any of them, replaced with an outlaw and had no ground hum problems.