Mike, first maybe I'd better re-emphasize that if we use the ordinary reasonably well-shielded coax, we shouldn't "expect" any noise. Be that as it may, coming through the air(i.e. the power supply isn't involved)might be electro-magnetic interference(EMI)or radio frequency interference(RFI)to impinge on the cable. The EMI is lower frequency stuff such as the 60 cycle hum induced from running a power cord in contact with the cable for a considerable distance, fluorescent lights, electric motors nearby, etc. RFI is higher frequency hash from very powerful and/or nearby transmitters.
Yeah, if you have a 1070 without balanced XLR outputs the discussion is pretty much just academic. Gave some thought about the widely separated inputs on the 1080 and didn't come up with anything sensible. Putting them both together near the center would need a few more inches of internal wiring, but that's insignificant.
