How long can an RCA cable be before it loses quality?
Composite RCA – 100 feet (regular); 250 feet (with extender)
Being analog, the image quality can degrade at longer lengths but the loss is not noticeable at 100′ or shorter. It is possible to go up to 300′ with a regular cable, but the quality level will vary.
Does RCA cable quality affect sound?
So, do RCA cables make a difference? Premium RCA cables can make a difference, whether you hear it or not depends on your setup and expertise. Good RCA cables make a lot of difference for trained ears and a good sound system. On the other hand, using $10 RCA cables on a $1000 system would be unadvisable.