TWo things I notice for best results:
1) use a FM frequency away from any stations you might want to listen to also with teh device on in that it can cause interference on frequencies adjacent to one used.
2) Be sure to match levels for best sound. In my setup Iphone 6s bluetooth to Otium to Alpine CS, setting otium level below 15 (half) results in clean sound. At higher levels distortion sets in first noticable by subtle sibilence in some tracks and getting worse from there. This means I must up the volume on teh Alpine a bit past where I normally would for other sources and turn it down generally when listening to commercial broadcast FM.
1) use a FM frequency away from any stations you might want to listen to also with teh device on in that it can cause interference on frequencies adjacent to one used.
2) Be sure to match levels for best sound. In my setup Iphone 6s bluetooth to Otium to Alpine CS, setting otium level below 15 (half) results in clean sound. At higher levels distortion sets in first noticable by subtle sibilence in some tracks and getting worse from there. This means I must up the volume on teh Alpine a bit past where I normally would for other sources and turn it down generally when listening to commercial broadcast FM.