On Tue, May 08, 2012 at 01:01:32PM +0200, Takashi Iwai wrote:
JFTR, we've seen users that report distorted sound on their macbooks when using jackd.
The workaround is to force 16-bit output:
http://jackaudio.org/macbook_distortionChip in question was the Cirrus Logic CS4206. We don't know yet which of the formats (32/24) is broken, maybe only one, maybe both.
Distrotion means noisy outputs or complete noise?
Noisy output, like clipping. As if the MSB would be wrong.
Here's an example:
http://www.youtube.com/watch?v=QD23mC_Dbek
And does this happen only with JACK? That is, if you run "aplay -Dhw" with 32bit PCM, does it play normally?
I've installed Linux on my spare MacBookPro and can report that JACKD is not to blame. aplay and jackd behave the same:
FLOAT_LE is distorted S32LE is fine
So only FLOAT_LE is broken, S32LE and S24_3LE are fine.
HTH