We just picked up our Conquest Lite 238RK and we are having problems trying to figure out what the undocumented stuff in the trailer is. The BT 100 and associated "sound system" is crap. We can barely read the display. We can't use the radio because when we set it to volume level 1 it's too loud. I was able to connect my phone via Bluetooth and play music through it, controlling the volume from the phone, but the sound was pretty bad. If, as DontTreadOnMe indicates, there are RCA cables connected to the back of the unit, then I'd guess the other end of those cables might be what's coming out of the wall next to the "Wi-Fi & Internet" plate (whatever that is). Does sound go out those RCA cables or go in those cables??? Who knows.
Regardless of the presence of an HDMI port, I'm pretty sure it's for audio only.
I did find a product manual at:
Pulitzer Prize-level it's not.