Has anyone tried buying a metal braiding and shielded the raw cable themselves? Did it improve the sound?
I have made ICs from the Duelund 20awg (DCA20GA600V) Tin Plate Copper Hookup Wire and shielded those cables using tinned copper braid shield connected at the source end only. The cables are balanced/XLR interconnects and they sound good with no noise issues.
I have also made speaker cables from the Duelund 12awg (DCA12GA600V) Tin Plate Copper Hookup Wire and did not shield them. They are constructed using a star quad geometry and bi-wired, so there are 8 individual runs of the 12awg wire to each speaker. Few companies shield speaker cables so I am not sure what you would achieve by shielding the speaker cables. If I were starting a speaker cable project with this wire, I would simply use their Dual DCA12GA 2x12 awg, Tin-plated, Stranded Copper, Oiled Cotton Speaker/Interconnect Cable. The cable already comes as a twisted pair in an outer sleeve, so they are essentially good to go as-is after adding the connectors of your choice. The already twisted and encased wire was not available when I made my speaker cables, so I used their hook-up wire.