audio latency is, essentially, the time it takes for audio data to move from your projector to your bluetooth speaker. wired connection produces an imperceptible amount of lag—about 5-10ms worth. within this 5-10ms window, your device processes digital audio data, converts said data to an audio signal, and streams the signal through your speak...

please see: how to manage locally stored files on the projector

please see: how to connect your mobile device with the projector via bluetooth

please refer to this video.

please see: how to cast and mirror your mobile device to the projector