Okay, it does control sound, though my 252RL only appears to have one zone. You can connect the TV audio to the bluetooth speaker, but there is only one - so no stereo. I need to try my bluetooth earbuds and see how that sounds. This is the first RV (of several) that does not come with an AM/FM radio (which I never use anyway.) I suppose I will have to dismount the device in question to see who the manufacturer is. There's always a learning process in a new RV. Thanks to all for your assistance.
Regards,
John