Quote: That does actually ring a bell. It was sometimes used for the older UE universal models like TF10 and the original SuperFi 5 Pro (and SF3 Studio I guess) because of their odd shapes. People could sometimes get a better fit by switching sides, and then compensate by reversing channels in Rockbox. Nothing fancy about it - a better fit will usually improve the sound. This wouldn't work for any other IEMs that fit the same way if you switch left/right sides.