I have an LG HDTV43LF5400 with no Audio output. It is connected to a digital Antenna and a Sony Blu Ray. I tried connecting a Sennheiser RS 120 headphones to this set-up. I can only connect to the Blu Ray (it only has HDMI and Coax connection). This only puts the sound while watching from the blu ray. When we switch the TV input to the Antenna, the sound does not work on the headphones. Any suggestions to have wireless headphones that can both play sound with either the blu ray or the Antenna?
Since the tuner is in the TV and the TV doesn't have an audio output you would have to modify the TV to provide an analog audio output. You would have to connect a speaker to line level converter to the internal TV speakers. You may also have to wire a switch to disconnect the internal speakers so you would not have to hear them all the time. If would void the warranty. Not electrically complicated but you would have to open the set.
Another option is to use an external OVA HD tuner. That will have HDMI out and analog audio out. You could then get an external HDMI input selector with audio extraction or an audio input selector for the RS120 transmitter.