I want to record and export in 48kHZ 24bit. I set this rate in the setting, but it is not available in the dropdown menu at exporting time. I have MAC ElCapitan
Select Custom FFmpeg Export in the “File Type” dropdown of the Export Audio dialog. Then click “Open custom FFmpeg export options”. In the intimidating dialog that appears, in the “Formats” list select “wav” and in the “Codecs” list select "pcm24_sle.
– Bill