Apply Chain

I set the Default Sample Rate to 11025 Hz, Default Sample Format to 16 bit via Edit/Preferences/Quality.

When I clicked OK, I can see that the Project Rate (Hz) at the left bottom of the screen is updated to 11025 Hz.

However, when I applied the batch processing (Apply Chain, Apply To Files) the rate at the left bottom of the screen goes back to the default setting of 44100 Hz when it was processing the files.

When the processing is done, I clicked Edit/Preferences/Quality to check if the default setting I did has been changed, lo and behold, it’s still showing 11205 Hz and 16 bit, while the left bottom of the screen shows 44100 Hz.

I’d like to reduce my speech audio files so that it won’t take too much space in my website provider, I will appreciate if someone out there can give me a hand in solving my dilemma, thanks a lot and happy new year to all…

Similarly, when you set the Preferences/Quality to 11025 Hz, 16 bit and open multiple files (20) to process, it’s re-setting the Project Rate to 44100 Hz when opening the files.


Please tell us what version of Audacity you are using (see the pink panel at the top of the page).

Chains does not have any way to set sample rate. It is a popular request that it should do so. When the Chain imports a file, the project rate changes to the rate of the current file being processed.

Are these WAV files? If they are MP3 files, reducing sample rate won’t reduce the file size unless you export using variable bit rate (VBR). If the files are to be streamed online, VBR won’t work.

Setting Default Sample Format to 16-bit doesn’t change the bit depth of the exported file, rather the bit depth a file is copied in as. Generally speaking, Default Sample Format is best left at 32-bit float, without getting into too much detail.

Tell us what format the files are then we can advise better.


Hi Gale,

  1. Version: Audacity 2.1.2

  2. I would assume that the Chain uses the current (active) Sample Rate setting?

  3. I am reducing Ogg Vorvis Files.

  4. I left the Sample Format at 32 bit.

You can recreate the problem by opening audacity (blank file), set the Quality Default Sample Rate to 11025 Hz, Default Sample Format to 32 bit then open a file (I believe any file) and watch how the Project Rate at the left bottom of Audacity changed. Now go back and check Edit/Preferences/Quality and you would notice that the settings you just did is still the same, it didn’t change a bit. It looks like the Project Rate is always set to 44100 Hz no matter how the Preferences is being set and that’s what Audacity is using and not Default Sample Rate in Preferences setting.

Thanks and best regards,

The sample rate set in “Preferences > Quality” sets the default sample rate for Audacity. This is used as the “Project Rate” for new projects (shown in the lower left corner of the main Audacity window).

  • The “Project Rate” is the sample rate that is actually used in the project. If tracks are at a different rate, then Audacity will resample the tracks on the fly during playback.
  • New recorded tracks have the same sample rate as the “Project Rate”.
  • Generated tracks have the same sample rate as the “Project Rate”
  • The sample rate of exported files is the same as the Project Rate.

When importing the first file in a project, Audacity will use the sample rate of the imported file and sets the Project Rate to match.
I believe that this was intended as a time saver for users that want to import a track, edit it, and then export with the same sample rate as the original track. In my opinion, this decision was a mistake because it overrides the user’s “Preference”, and it is inconsistent in that it only applies to the first imported track. This means that you need to be very careful when importing tracks of mixed sample rates because if the first track has a low sample rate, then the entire project will have a low sample rate which will cause loss of sound quality. However, it’s been like this for a very long time and some would consider it a “regression” to remove this “feature”.

A possible “feature request” to work round this problem could be to add another Preference setting:

| Default sample rate: [44100 Hz] [44100]
| Allow first import to override default sample rate [x]

Default sample format [32-bit float]

The "Allow first import to override default sample rate " option, when checked, would give Audacity the same behaviour as we have now.
When not selected, the behaviour would be to always use the “Default sample rate:” setting when importing tracks.

For your use case, you would then be able set the “Default sample rate” to 11025 Hz and to de-select the “Allow first import to override …”. The Project Rate would thus stay predictably at 11025, so the exported files would be at 11025.

We can add your vote if you would like to support this feature request, or feel free to describe an alternative.

Try OggDropXPd

But you might want to over-ride for Chains and not otherwise, and you might want Chains to use some different sample rate than default.

If I was using Chains I would find it more intuitive to set sample rate parameters there not in Preferences.

So I think the usual request to add sample rate to the Export command in Chains is better, irrespective if we make the current “first file changes the project rate” behaviour optional. There is only ever “first file” when applying Chains to imported files, so people may not see the connection between the Preference and Chains.

Of course Ed Juan can vote for what he wants.


My suggestion is not exclusive of other improvements, but in this case, if Audacity obeyed the user’s Preference setting, as one might reasonably expect it to do, then Ed Juan would not be writing to the forum with this problem (for which Audacity currently has no solution).

I agree that the ability for users to overwrite the sample rate preference setting in Chains (and in normal export and Export Multiple) would be useful.

I also think that it would be useful to have an option in Preferences to use the sample of imported files as the Project Rate “if higher” than the default (thus maintaining quality, regardless of the order in which files are imported).

Neither is mine. It would probably be useful to have one or more options for project rate behaviour when importing as well as to set sample rate with the Chain export format. However we get far fewer complaints with the current project rate behaviour on import than we had before we changed it.

I still argue that some users would not find the Import / Export Preferences setting if that was the only way to adjust sample rate behaviour in Chains, as well as it being less flexible to do it that way.

Perhaps you would like to start a new “Adding Features” topic about options for project rate behaviour when importing? We discussed it not so long ago on -quality I recall, without reaching any conclusion, so perhaps refer to that too.


Hi Gale,

I agree with Steve about an option of setting Project Rate in Chains since it will be more of a direct approach when you open/create and edit your batch file. Furthermore, this “first file changes the project rate” might be a redundant option if you can set the Project Rate in Chains, meaning, who would open multiple files and work on them? Unless of course, you’re not aware that there’s available batch file for you to use.

A work around I used to open 20 files at a time is to set Preferences/Quality to 11025 Hz, then press OK the first time. The Project Rate is updated and Audacity uses that rate for all 20 files. It’s interactive though, since I have to close/don’t save each file that I’m working on, more steps are required, but good enough for me since Chains is not working the way I want it to be.

Once done, I will open another 20 files, visit Preferences/Quality and just click OK, I don’t have to change anything since nothing is changed during processing. I don’t know the maximum multiple files that Audacity allows you to open, I just find out that it freezes when I tried to load 60 files.


The number is limited by the capability of the computer.
Note that both the number of tracks and the length of tracks is important. As the number and/or length of tracks approaches the limit of the computer’s capability, Audacity will gradually become increasingly sluggish and eventually unusably slow.
(Running out of disk space is likely to make Audacity crash).

I think that makes more sense for the case of Chains, as I said. I counted your vote for that on our Feature Requests Wiki page.

For example there would not be much point in a Chain if you were just importing two files to mix them together. But you may care if the first file you imported was at a low sample rate and then the second higher sample rate file you imported did not change the project rate to the rate of the second file.

Do you mean you are importing the files using File > Import > Audio… and then change Default Sample Rate? It would be easier just to change the Project Rate after import. I am not sure what your workaround is though, because if you remove all the tracks of the previous imports then import more files, the project rate will change again to the rate of the first imported file.

Or are you using File > Open… ? That will limit you because there there is a limit to how many project windows your machine can handle. And I still don’t see what stops the project rate changing in that case.

What I would do if I wanted to do this is to stop the project rate changing. There are at least two ways. One is to create a “dummy” file at 11025 Hz and name it so that it would always be imported first, such as 0000001.ogg. Then File > Import > Audio…, but include the created file in the imports. Then the project rate would stay at 11025 Hz. The dummy file would get overwritten each time when you export multiple, just like the other files, but that does not matter as it is only a dummy file.

Or, in a new project window, add an 11025 Hz track (for example, Generate > Noise…). Mute the track, which means it cannot export. Save the project, then open that saved project when you want to work on your files (launch Audacity by double-clicking that AUP file). The project rate will then stay at 11025 Hz irrespective of the rate of the files you import.

OggDropXPd would be quicker still though.