sebuschi wrote:Assume I want to record through an AD converter which is capable of e.g. 24 bit and 96 kHz.
I would like to work inside of audacity with this specifications, but at the end convert it to CD quality (16 bit, 44.1 kHz).
In this situation, it would be best to work in Audacity in 32-bit float / 96 kHz, then export as 16-bit 44.1 kHz.
To do this, go to "Edit menu > Preferences > Quality", and set the default sample rate to 96000 and the default sample format to 32-bit float.
When you are ready to export in CD quality, change the "Project Rate" (lower left corner of the main window) to 44100, then export as 16-bit WAV.
Note that there is no real benefit to working with 96 kHz over 44100 Hz (the only marginal benefit is increased frequency bandwidth, but you lose even that marginal benefit as soon as you export), but working in 32-bit float has very definite benefits over working in 16 or 24-bit. My recommendation would be to work in 32-bit float / 44100 Hz.