Re: How does Sonar decode m4a files?
2016/08/02 19:06:44
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Original wav file ripped from CD nulls with m4a/ALAC rip using itunes when both are imported into Sonar.
The same wav file played through a Sonos Connect and recorded all digitally (i.e. no A/D or D/A) also nulls with the original wav file.
However, the m4a/ALAC played through a Sonos Connect and recorded digitally does not null. I originally wondered if the m4a->wav codec might be the issue (Sonos runs a version of Linux internally, so doesn't use the windows codec), but I now doubt it.
I think the issue is that Sonos (not Sonar) honors the volume normalization ITUNNORM metadata tag that itunes adds when ripping any file. Sonos docs don't mention using this tag for ALAC files, but I think this is what is happening. I've just figured out how to change the ITUNNORM tag to set the volume normalization to zero (not trivial, as it turns out), so I'll run some tests today.
Ultimately I'd like to play my music just as it is on the CD, not normalized (which includes limiting, so the sound is compressed somewhat). It is not really feasible to change the tags on all my ripped ALAC files. When I'm sure this is what is happening I'll need to talk to the Sonos developers.
Cheers, Peter.
i5 6500, H170M, Intel HD 530, 16GB, Focusrite Scarlett 8i6, Win 10 Pro (1803) (64 bit), Cakewalk by Bandlab