Why I gave 3 star situated on the audio output through the 3.5mm plug. It hums sometimes very strongly for no reason, and disappears after a certain time (several 10 minutes) and come again sometime. If the Audio dispensing buzzing about Beamer, then the audio output from the laptop is humming well just until the HDMI cable is disconnected, the hum disappears from the laptop. The audio output from the projector hums on, even if the projector is turned off (power cord). Instead beamer with a television appearance never happens. I start from a defect and send the projector to share back.