A:
This projector DOES NOT have any audio inputs or outputs, & it DOES NOT have any built-in speakers
What it DOES have:
2 HDMI (for video only)
1 composite
1 component
1 PC
1 RS232C
1 Trigger Out (to send a signal to motorized screens to come down when the unit is turned on)
If you want to use a Chrome Cast, you have to put that on your audio receiver (assuming it has a "monitor out:", that output will then need to go to the projector.