Sample Rate question

I’m using Mac OS Big Sur 11.4.
I’m using Audacity 3.0.2.

I’m using a recently purchased USB cassette capture device (MIUONO brand) from Amazon and am trying to digitize some of my old cassette tapes onto my Mac. So I am very new to using Audacity and have tried to learn what I could, especially from the Audacity guides “Recording with USB turntables or USB cassette decks” and “Mac and USB input devices.”
[Note: In this Audacity Q&A forum, I recently posted a problem I was having with the Monitoring not working, and thanks to someone who responded, I did get that problem solved. But now I have another question about the Sample Rate when digitizing audio cassettes.]

From what I’ve read numerous times in the guides and Q&As, the Sample Rate in Audacity has to match that of the device as seen in Audio MIDI Setup. Under Audio MIDI Setup, I see a USB PnP Audio Device with a 48,000 Hz format, 2 ch 16-bit Integer setting. There is no pull-down menu or option to change this setting. So to match the Audio MIDI Setup rate, in Audacity I set the Sample Rate to 48000 Hz and the Format to 16-bit.

BUT sometimes I want to burn CDs from these audio files after I’ve digitized them, and from everything I’ve read, CDs always have a sample rate of 44100 Hz. So what should I do?
Will I be able to burn CDs even if the Sample Rate of the imported audio is 48000 Hz instead of the usual 44100 Hz?
Or, even if the Audio MIDI Setup shows a 48000 Hz sample rate (which can’t be changed), should I change the Audacity Sample Rate to be 44100 Hz, and have them not match each other?

Thanks to anyone who can help me out. (I did try to do a search in this Forum to get this question answered, but without luck.)

CDs always have a sample rate of 44100 Hz. So what should I do?

You could leave it up to the Audio CD authoring and burning software. 44100 (audio CD) and 48000 (video) sampling rates are very common and (for one example) most video editing programs automatically convert in the background without making a fuss. I wouldn’t be shocked if your authoring and burning software did, too.

You do need to be careful not to make a Data CD by accident. Those are little, shiny hard drives and don’t care what you put on them as long as it fits.

Do you have a CD music player? Make an Audio CD. See if the burning software is OK with it and see if it plays.


There is a caution here. Do not use the CD in your computer as the playback test. It’s not unusual for the CD Device software to “help you out” by playing a video sound track on a Data CD. The CD player in my truck is old enough to only play Audio CDs and I have a portable CD player. I use the portable player as a test when I used to make audio CDs for my sister. It won’t play anything but a perfect Audio CD.

You can make a special sound track and convert it to 44100 by changing the Project sample rate with the little window in the Audacity lower left. Export as normal. But that will give you two versions of the same track for, in my opinion, no good reason.


Thanks for your reply, Koz. But, maybe because I’m sort of a novice here, I’m not totally sure I’m understanding what you are saying.

First of all, after I’m digitizing my cassette tapes, I’m importing them into Apple Music on my Mac, and then I make Playlists and burn CDs from there. So that’s my burning software.

So in your first reply to me, are you saying that even if I digitized the audio in Audacity at 48000 Hz (to match the Audio MIDI Setup), that when I burn a CD from Apple Music, it might automatically convert it to 44100?
Is it really true that audio CDs are ALWAYS in 44100 Hz? So if the Audacity sample rate is 48000 and I am able to successfully create an audio CD after I export it from Audacity and then import it to Apple Music, does that mean that the Apple burning software automatically converted it to 44100?

I do know the difference between data and audio CDs and I always burn audio CDs, so that is not an issue. I have burned lots of CDs from my Mac before; I’ve just never digitized cassette tapes using Audacity before.

Then in your second reply, you wrote, “You can make a special sound track and convert it to 44100 by changing the Project sample rate with the little window in the Audacity lower left.” I don’t really understand what you mean by “you can make a special sound track” – what is that? And I also don’t really understand when you write, “that will give you two versions of the same track for, in my opinion, no good reason.” Two versions?

So, apologies if I sound dense, but I still have my original question: Given that the Audio MIDI Setup rate is set (inflexibly) at 48000 Hz, is it better if I also select 48000 Hz in Audacity? – or should I select 44100 in Audacity, thus making the two not match each other?

The short answer is to work with whatever project rate you want, but when you are doing the final WAV export for the CD, change Audacity’s project rate to 44100.

OK, so to see what is going on here:

  1. In an empty project, set the project rate to 48000.
  2. Generate a tone: Sine, 1000Hz, amplitude: 0.45, duration: 60sec.
  3. Now duplicate the track: Ctrl/Cmd+A, Ctrl+D
  4. Select the second track only and Tracks > Resample to 44100.
  5. Select the second track and zoom in about a dozen times (Ctrl+1) until you see the individual samples. Notice that these two signals appear identical.
  6. Now zoom in a few more times. The signals still appear identical, but try dragging slowly to select some audio in both tracks. As you drag you will notice that although the audio is identical, the sample points are at different places.

When you “Export” a project, the entire project is resampled to the Project Rate as necessary. Go ahead, export this project this project to wave. Call the file wav48000. (You can ignore the “mix” warning if you get one). Close Audacity.

Now, open a new project and set the project rate to 44100. Import > Audio > wav48000. Note how the rate in the Track Control Panel is set to 48000 and also that Audacity’s Project Rate is now set to 48000.

OK, so now change Audacity’s project rate to 44100 and export to wav44100. Explore both save files in File Manager/MacOS. Note that the 44100 file is just a tad smaller than the first. OK, bring (Import) both files back into Audacity and note they are identical (except for the sample rate).

I hope this helps. :smiley: