BIL had some serious home Hi Fi years ago, with all those fancy expensive cables on show. however where they went into the floor, we cut a hole in the wood, placed a brace under the floor, and fed the wire from one end to the other. Then, because the cables were 2m long, we cut them in half, and used regular 2.5mm copper house wire to extend them under the floor, and regular chocolate block terminal blocks to join them. Cable used was some recovered cable as well, just scraped off the black oxide both sides to get a clean joint, and then put the plank back with some screws, and a corner cut out to allow clearance. Worked well enough, and was a cheap method to get fancy cable in a really long length, and nobody could hear any difference.
Some of those fancy cables were really poor quality, did plenty of work on some to resolder poor connections to the plugs, which had snapped off, because the heavy gold plate turned the solder purple. Add solder, flick off onto newspaper, and replace with more solder, and push the wire actually into the hole. Still have some, I use them as a source of nice PTFE coated silver plated test leads, using cheap plugs I got from Frankie.