Use Audiojack instead of HDMI audio

[baryluk]

Try playing something directly to alsa. I often have bad experience with pulse audio and multiple audio cards


for example:

mplayer -ao alsa:device=hw=1.0 some_audio_or_vide_file.mp4

also for volume manipulation check alsamixer from the console. With F6 key you can select cards, and with key M you can mute unmute channels.