I have them since 1 month ago. I am working with a small church band (4 vocals and 4 instruments). I am currently using a system with 3 Tranceivers and 8 receivers. These are good products with good quality, very easy to configure. Especially, the FOCUS MODE is very usefull because with 1 tranceiver I can send 2 different signals and I can connect 2 instruments on it(e.g. drums and bass on same tranceiver with 2 bodypacks, on L input is the BASS+mix and on R are the DRUMS+mix, on their bodypacks they hear on both headsets their corresponding audio signal).
When the batteries are begining to drain out, a weird noise is heard in the headphones.