The audio receiver is a Yamaha HTR-5550, with plenty of RCA inputs and outputs, plus video, S-video, Coaxial and optical. Most of these I haven't ever used, but I have used the optical inputs and outputs, so I hooked up a Pyle receiver-transmitter PDWM18BT via the optical system, and attempted to connect to 2 Bose bluetooth speakers, Soundlink Flex SEs. Result: The Pyle BT adapter sees and recognizes the two speakers, but is unable to deliver any signal.