Track Bit Rate Display

There are numerous posting on this forum about changes to Project Rate, Default Rate, whether it is displayed on screen or not displayed etc etc etc. I think the new version is OK once you get used to it.
But my query is the Rate that is dsplayed on each track…???. This is the rate that the file is opened or imported at, OR if a recording the recording is recorded at the Project Rate and displayed on the track.
All this is OK for one or two tracks …recording, or opening files etc and simple mixing and playing or exporting.
If I … Open Audacity, check Audio Setup button…says Project rate is 44100.
But, then for a new project I open a (11025 bitrate saved) file it will open at 11025, and will change the Project to 11025. I then open another different file (saved at 22050) it will open at 22050 as displayed on track2, and I play these together, they will play at the Project rate say 11025…OK… It is playing at 11025 (and displays playing at 11025 at bottom of screen) but the track displays shows 11025 for track1 and 22050 for track2…??
If now I go back to start of track and do a recording of someone singing…it will record at project rate 11025 … OK, but it is lower than I really wanted and didnt notice it until recorded??.. now three tracks 11025, 22050 and 11025.
Can I edit this track only… probably not mutch point because the low bitrate is already there…if I re-sample that track it will just give a higher bitrate of the same low quality record… and also what will it do relative to the other tracks that are there…??
So, what is the point of displaying the Track rate on each track and what does it mean if it will be playing at the Project Rate.
Is the Track Rate only a Display Rate to show the samples per sec in relation to the waveform cycles displayed…???

Is there any tutorial anywhere describing how this is meant to be used and how to edit a project with several tracks each showing different Track rates…??

This section in the Manual attenps to explain this.

basically the Project Sample Rate and Project Sample Format are what are use on Export and Playback.

But things are due the change for the next release - the intention is that:

  1. you will be able to specify rate and format in the Export dialog

  2. Importing your first audio file into a project will no longer change the Project Sample Rate.

And in even later releases it is likely that the sample rate and sample format will no longer be shown in the Track Control Panel for each track (but will still be accessible in the TCP dropdown menu).


Other related changes that are coming in 3.4

  1. You will no longer be able to create s stereo track from two mono tracks with mismatched sample rates.
    This is a long-standing bug in Audacity (present since version 1.0.0)

  2. You will no longer be able to open a project that has a stereo track with channels with mismatched sample rates


If you are going to mix different sample rates just make sure to check/change the project rate to what you want.

You can also go to Tracks → Resample to make all of the tracks the same, but you’ll still want to check the Project Rate.

The soundcard can only run at one sample rate at a time and of course the exported file can have only one sample rate. If you are running two different audio applications (or something like that) windows will resample the audio as necessary so the sounds can be mixed and played together. Most soundcards run at 44.1 or 48kHz by default and Windows is often re-sampling without you knowing.


More information never hurts!

Note: The sample Rate or Project Rate (kHz) is different from Bit Rate (kbps) or Bit Depth.

Sample Rate is the number of samples per second.
Bit Depth is the number of bits in one sample.

Bit Rate is the number of bits per second. (kbps - kilobits per second) It’s directly related to file size and normally talk about bit rate when we are working with compressed files as an indication of the amount of compression or the quality of lossy compression (like MP3).

There are 8-bits in a byte so if we know the bit rate we can divide by 8 to get file size in kilobytes per second (ignoring any embedded artwork or other metadata that adds to file size).

You can calculate the bit rate for uncompressed files. A “CD quality” WAV file is 16-bits, 441.kHz, 2-channel stereo so the bit rate is 16 x 44.1 x 2 = 1411kbps, and that works-out to 176 kilo bytes per second or about 10MB per minute. A good quality MP3 might be 256kbps or about 1/5th the size.

Thanks for the info…I dont have a problem with bits and bytes or Project Rate, actual or default my query was regarding the display of the sample rate on each track… What does it relate to…??, How is it dealt with when editing etc etc…

???.. I didn’t think you could have a stereo file MP3 or WAV etc with Left and Right on different samplerates…There is only one field in the file Header for Samplerate…??

You are right. That was an Audacity issue where you could create a “file” (or project) like that in Audacity and then I think it was messed-up when you export.

OK, DVDdoug, thanks, Any logical explanation regarding the Track samplerate display use or whatever.??

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