excaliburm
Member
- Joined
- Apr 29, 2022
- Messages
- 16
- Likes
- 3
My sub has 60hz hum, which seems to be caused by a ground loop (only manifests when connecting via RCA cable to the receiver). The sub is powered by a different outlet (no way to work around this), so a ground loop would make sense.
There is quite a bit of discussion on the forum to avoid ground loops, as well as balanced cable wiring, but I am in a somewhat unique situation where my source (AVR) has a balanced output for the subwoofer, but the powered subwoofer itself only has an RCA input. Based on my understanding of balanced signals, if we take the difference between the signals carried on XLR, and output unbalanced signal referenced to the subwoofer ground, the hum will be removed. Is this understanding correct, and is there a box/converter cable which essentially does this (and would this approach allow me to get away without a isolation transformer)? Or is there any other way to take advantage of the fact I have a balanced source (but not sink) to avoid the ground loop?
There is quite a bit of discussion on the forum to avoid ground loops, as well as balanced cable wiring, but I am in a somewhat unique situation where my source (AVR) has a balanced output for the subwoofer, but the powered subwoofer itself only has an RCA input. Based on my understanding of balanced signals, if we take the difference between the signals carried on XLR, and output unbalanced signal referenced to the subwoofer ground, the hum will be removed. Is this understanding correct, and is there a box/converter cable which essentially does this (and would this approach allow me to get away without a isolation transformer)? Or is there any other way to take advantage of the fact I have a balanced source (but not sink) to avoid the ground loop?