Re-Sampling from 96 to 48 kHz

(Not MacOs-specific, but I don’t know where else to ask the following question, since I’m on a Mac, anyway.)

Suppose I’ve got a lossless audio file (WAV or FLAC) with a sample rate of 96000 Hz. Now I want to convert it to 48000 Hz. In the audio date there is spectral contents above 20 kHz, which – of course – must be removed before; otherwise it will result in artifacts at lower frequencies (aka “aliasing”).

My question is: Do I need to apply a low-pass filter manually? (If so, which kind filter?) Or will Audacity automatically care for anti-aliasing, when I use the menu “Tracks"→"Resample”?

thank you in advance for enlightening me
Walter

PS: I’m still on Audacity 2.3.0 (in case this matters)

As you are on Mac, this board is a good place to post.


No you don’t. Audacity’s resampler will handle that.

If you only want to convert a file’s sample rate, you don’t need to use the Resample command.
The sample rate of exported files is determined by the “Project Rate” (lower left corner of the main Audacity window.
All you need to do is:

  1. Import the file
  2. Set the “Project Rate” to 48000
  3. Export the file.

In this case that does not matter, but good to say that in each post as sometimes it is important.
Audacity 2.4.0 is due to be released next month, (and it is supported by Catalina). I recommend upgrading to Audacity 2.4.0 when it is available.

THX! Good to know!

Will these steps, too, include anti-aliasing?

Yes.