Epson 800p - Manual (Page 97)

Appendix A: Connecting to Additional Equipment 91
Connecting the Audio Cable
If your presentation includes sound and you want to use the
projector’s built-in speakers, you’ll need to connect a stereo, mini-jack
audio cable (not included). If you connected the USB cable, you may
not need a separate audio cable.
1. Connect one end of the audio cable to the Audio 1 jack on the
projector.
2. Connect the other end of the audio cable to the speaker or audio
out port on the Macintosh.
Audio1 jack
audio cable