I've used the Intelix extenders, but there was a SLIGHT hum on the line. Probably 10x quieter than anything you could ever hear, but I could see it on the BSS meters and it bugged me. You could only hear it if you had the system turned up over halfway with no source audio playing. Also this was in a commercial install with 100-150' wire runs and tons of 120v and 240v lines all over the building.