Hello AVS Members,
This is my first post here but I can say that I have visited here on a number of occasions and always found this forum quite informative, which is why I would like to raise a question here.
How do uni directional subwoofer cables actually work?
I have done some research and the only viable explanation is the ground loop theory. This means that the ground shield of the coaxial cable is not connected at the subwoofer end to reduce the chances of hum as a result of "hearing" the amp at the other end.
So I dug out a spare coaxial RCA cable that I had with a screw off plug so I could take a look inside. I could see that the inner core was connected to the inner part of the connector and the woven copper shield was connected to the outer part of the plug (as expected)... So I decided to test out this theory and I cut the part connected to the outer woven copper shield to the outer part of the plug and tested it out on my subwoofer (again a cheaper spare sub as I don't want to risk blowing up some good stuff!)... However, the result was an extremely loud hum! Which is exactly the opposite to what this theory prescribes.
Have I misunderstood something? Which part exactly is meant to be left disconnected to create a uni directional subwoofer cable?
This is my first post here but I can say that I have visited here on a number of occasions and always found this forum quite informative, which is why I would like to raise a question here.
How do uni directional subwoofer cables actually work?
I have done some research and the only viable explanation is the ground loop theory. This means that the ground shield of the coaxial cable is not connected at the subwoofer end to reduce the chances of hum as a result of "hearing" the amp at the other end.
So I dug out a spare coaxial RCA cable that I had with a screw off plug so I could take a look inside. I could see that the inner core was connected to the inner part of the connector and the woven copper shield was connected to the outer part of the plug (as expected)... So I decided to test out this theory and I cut the part connected to the outer woven copper shield to the outer part of the plug and tested it out on my subwoofer (again a cheaper spare sub as I don't want to risk blowing up some good stuff!)... However, the result was an extremely loud hum! Which is exactly the opposite to what this theory prescribes.
Have I misunderstood something? Which part exactly is meant to be left disconnected to create a uni directional subwoofer cable?



















Whether it's disconnected on the one side or the other, noise that would be on transmitted onto that shield can't propagate, just like any wire that's only plugged in on one side cannot transmit anything.

