As often happens when a new technology comes along, a new variable is introduced into the mix of obtaining best system performance. It is certainly true that locating the transmitter farther from the audio system will reduce the the RFI generated to levels which are not audible. Choossing different cables and equipment will also help here, but that isn't so easy after one has already purchased a system that provides satisfying results. I believe I have an RFI problem in my system because I have a cable carrying video information running for about three feet along side my speaker cables. i cannot easily change this and keep the wife happy. I don't know how audible this is, but I always seem to have a very low volume buzz through my system. it isn't audible unless i put my ear right up against the speaker grille cloth, but the fact I can hear it at all suggests it will obscure low-level detail in audio playback.
I know that Charles hansen's Ayre gear is designed to reject as much RFI as possible and a friend's Ayre system is DEAD QUIET. There are certainly other manufacturers whose gear does the same.
So, just one more variable to consider when designing or tuning one's system.
