Make sure the Tablets are on the Staff wi-fi and logged in.
Start-up using these instructions:

This is a dongle on the back of the TV It may require restarting by unplugging it. It is about 1 1/4" in diameter, black in color with a connecting cable and input cable.The TV input must be selected for Chrome cast before turning on the tablet.

Use stereo only on the Android sound output setting because the Bluesound can’t process anything that’s surround-sound. The TV needs to be set on PCM. These photos show to scroll positions for two selection items in TV setup.

this is on the App on Greg's iPhone and controls the volume of the sound bar remotely. It can limit how loud the bar will play.

Make sure the sound level on the tablet is up all the way and then use the TV remote to control the volume.