Audio Problem OS X - high pitched screeching noise

[easymusiclab]

Hi folks,

I have a problem regarding VLC on my 2011 27" iMac (Intel i5 Quad with 16 GB RAM). I use a FireWire MOTU 896 MK3 audio interface and I'm running OS X Lion.

The problem occurs during playback of both types of files: .mkv and .avi (so it doesn't just occur with high definition codecs).

Playback is completely unbearable since the audio signal drops out every couple of seconds and produces an irritating high pitched screeching noise before it continues again.

The video playback is smooth and couldn't be better.

I am 100% sure that the audio problems are not due to weak hardware.

If I change the sound output in OS X to the internal speakers of the iMac, everything works just fine.

Please help me to fix this so that I can watch movies again with decent audio...it sucks playing audio through the internal speakers.

Thanks for all your help!


Please do not suggest that there is a problem with my audio interface, my audio interface is used for music production and works just fine in all cases expect for vlc. I have kept all settings in vlc at default...maybe I need to change something there?

[rphogue]

I've had a similar problem with Apogee Ensemble. It seems VLC does not like multi-channel firewire audio interfaces. VLC totally seized control of any volume control, called tech service at Apogee Digital, and they were very much aware of a problem that exists since version 1.0 of VLC - apparently a bug causes a multiply operation instead of an add operation - causing the volume to be abnormally loud.