Check out the posts that mention AES48. My gear supports this so I use 15 foot Benchmark XLR’s that are low cost and sound excellent with this supporting gear. If If I was able to put a hole through a Livingroom wall I would use 50 foot XLR’s to get my rig completely out of the room.
Luxman gear, for example, does not support this standard and I would not use my Benchmark XLR’s with that, nor would I keep my amp(s) so far away from the preamp. First of all it would be very expensive to buy commercial grade XLR’s and I do not have confidence it would be good. Pro gear such as Weiss, Benchmark, CODA, and I think, Bryston support this.
One thing I noticed with LONG wall speaker placement in my Livingroom was that the speaker just 1 foot from the front wall was OK. I think this is because I have 7 feet to my left side wall and 5 feet to my right side wall. That right side wall is a partial wall that opens up to the family room. I also have 25+ feet of ceiling height in the Livingroom. All of the LONG wall space is what likely makes the sound work with a floor stander so close to the front wall.