Choppy sound via HDMI on Mac Mini 4,1

I get choppy sound output over hdmi with the command.

aplay /usr/share/sounds/alsa/Front_Center.wav

My current configuration can can be found here:alsa-info.sh output

Sound worked after some tweaking with 10.04. After upgrade to 11.10 sound stopped working properly. A fresh installation of 11.10 did not change the situation.

Video over hdmi works without problems. As soon as I run speaker-test I get fluent sound again. Workaround to trigger speaker-test after login is obvious but I would like a real fix to that problem.

How can I fix this?

1 Answer

This problem was solved by the OP:

The following configuration fixed the problem:

1) Added the following line to /etc/pulse/default.pa

load-module module-alsa-siice=hw:0,8

2) Added the following line to /etc/modprobe.d/alsa-base.conf

options snd-hda-intel model=mbp55 enable=1 index=0 position_fix=1

The last three parameters actually solved the problem. Before that I had to run speaker-test to get fluent sound. dmesg returned the following error but afterwards sound was okay.

hda-intel: Invalid position buffer, using LPIB read method instead.

3) I am not sure if this is related but I had temporarily success with the following grub boot parameter in /etc/default/grub

GRUB_CMDLINE_LINUX="nomodeset noacpi"

I am still not sure what the problem was. If anyone could tell me I would like to learn it. Thanks.

Some useful resources:

ftp://