sample rate question

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soundmix2k
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Joined: Tue Jul 16, 2019 7:23 pm

sample rate question

Post by soundmix2k »

What is the relationship between the Mac audio interface hardware sample rate and the sample rate recorded by Amadeus Pro?

TLDR: I've got a DAT player connected via SPDIF Optical to a 2012 Mac Pro running mac OS 10.12 Sierra. Looking in Audio MIDI setup my source is set to Digital In and the format sets itself to either 48k or 44.1k depending on the sample rate of the tape I play. But I can set the sample rate in AP separately, which would require sample rate conversion if there is a mismatch. Perhaps sample rate conversion is always being applied, even though this is a digital connection? I hope that if the sample rates match, no conversion would be applied, but I'd love to know for sure.

One other observation - when I record a tape that switches sample rate in the middle, the Mac's digital input switches sample rate correctly, yet AP produces a file that sounds fine, but is entirely recorded at the sample rate I set initially. So there must be sample rate conversion applied to the part of the file after the switch.

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Martin Hairer
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sample rate question

Post by Martin Hairer »

I hope that if the sample rates match, no conversion would be applied, but I'd love to know for sure.
Correct.
One other observation - when I record a tape that switches sample rate in the middle, the Mac's digital input switches sample rate correctly, yet AP produces a file that sounds fine, but is entirely recorded at the sample rate I set initially. So there must be sample rate conversion applied to the part of the file after the switch.
That actually happens at the level of the system's Hardware Abstraction Layer, before it even gets to userspace applications like AP. Regards,

Martin

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soundmix2k
Posts: 2
Joined: Tue Jul 16, 2019 7:23 pm

Re: sample rate question

Post by soundmix2k »

Martin Hairer wrote: That actually happens at the level of the system's Hardware Abstraction Layer, before it even gets to userspace applications like AP.
Understood. Thanks much for the info.

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