I have a Sony HTXT1 soundbar. It is connected via HDMI. The soundbar does have bluetooth functionality, but I believe this functionality is input only, rather than output. Is there any way I can buy an additional speaker (ideally wireless of some sort) and the audio play through the soundbar AND the additional speaker at the same time (in sync)? I can't think of a way to do it since the TV sound does not play at the same time as the soundbar...so, it tracks that anything plugged into the TV would not play at the same time, and I think if I plug something into the headphone jack of the soundbar, the sound then won't go through the soundbar either. Is my only option really to get a whole different soundbar? Thank you.
I am not aware of any soundbars that have BT transmitters built in so changing the soundbar won't help.
Instead of using the HDMI-ARC to get audio out from the TV you can use optical audio out.
That can be split to connect to both the soundbar and a bluetooth transmitter. You will probably need to set the TV to output in PCM stereo if it isn't already set that way, Check the TV manual on how to turn on and configure the optical output.