I’m with @rego on this one - the type of connector i.e. whether you use IEC, BNC or XLR, is mostly immaterial when it comes to cable performance.
The cable’s geometry, the quality of the wire and the capacitance of the insulations used AND the quality/design of the actual connector can make more of a noticeable difference.
Granted, BNC is designed specifically for Digital connections, but even a quality BNC connector on a poorly designed cable will not sound as good as as well designed cable with either RCA or XLR connectors.
Trouble is - most cable manufacturers DO NOT publish their geometries, so it is very often difficult to assess how well a cable is made and hence how well it may perform.
You can spend a lifetime trying different cables and each time you’ll probably hear changes - but you are still basically "guessing" each time you make a choice.
There are two options...
- buy cables from companies like InAkustik, or Nordost.
- build your own, then you control all of the cable’s parameters
Companies like InAkustik and Nordost (and a few others), that reveal their geometry’s, allows the educated customer to make an informed decision.
I chose the DIY approach and have never looked back.
But then - my DIY cables are built from scratch
- I DO NOT just solder a fancy connector onto a piece of bulk cable
- I build the the actual cable from individually sourced wires & connectors
It really boils down to how picky YOU are :-)
Regards - Steve
