Slow Export

I have been an Audacity user for a number of years and process the podcasts of all of my lectures using the software. That would be, to date, over a thousand lectures, most between 45 minutes and two hours in length. My workflow is consistent in Audacity. Unfortunately, I just installed the new release, Audacity 2.1.2, and a problem I have never encountered is preventing me from completing the export. Before this release, export in MP3 format took between two and four minutes to complete. Yesterday, with the new Audacity release, the export was going so slowly that I had to stop it after a couple of hours. Everything about my workflow was identical to what it had been for years; yet, the export progress bar was barely moving.

My operating platform is Windows 8, deployed on a high-end computer with 24 Gb of memory and ample room on two hard drives, one an SSD, the other a one Tb 5400 rpm. The files I bring into Audacity for processing are MP3 format and average around 50 Mb in size, and the associated exported files are MP3 format at about the same size.

Prior to initiating export, the software was behaving exactly as it had in prior releases. I do notice that there are selections in the export window I had never seen before, and I attempted several different bit rates (other than my usual 128 kbps), but nothing improved the export speed.

I am now behind in uploading podcasts, and the situation will worsen every class day. Does anyone have a suggestion concerning what’s going wrong? I am grateful for any help provided with this matter.

Let’s try some simple tests to see if we can work out what is going wrong.

  • Start Audacity from fresh.
  • If you’re working with stereo files, create a new stereo track using the “Tracks” menu and ensure that the track is selected (if you click on the track and press “Enter” it will toggle between selected and not selected. It is selected when the box on the left of the track is the dark colour).
  • Click the “rewind to start” button (" << ")
  • Generate a 30 second tone (Generate menu)
  • Export as an MP3 file and give it the name “test.mp3”.

Does that work?

If it does, try the same but with a 45 minute tone.
Does that work?

If it does, try again but use the same file name as you were using when it didn’t work.
Does that work?

If it does, restart Audacity and make a 1 minute recording, then try to export that.
Does that work?

Thank you for the swift and detailed reply.

In response to your suggestions, I did all of the tests you described, and every one of them exported quickly. In fact, the second test, a 45-minute tone export, took about the same amount of time to export as one of my 45-minute lectures used to take in earlier releases of Audacity. The short tests, the 30-second tone and the one-minute audio, exported in a matter of seconds.

I should explain the structure of my podcasts: Step one is to import the raw, MP3 stereo recording from my Zoom H1 (I put the file into a hard drive directory and then pull it into Audacity from there); step two is to import an intro stereo track (50 seconds in length) that begins the podcast and a closing, four-second music finale; step 3 is to overlay a recording (done in Audacity) of introductory information about the podcast onto the intro music.

Okay, here’s the upshot. I just went through my usual workflow for one of my pending podcasts (the one I had tried three times yesterday to process and export). The export began with the “Time Remaining” going up toward one hour, and then, all of a sudden, the progress bar started racing forward, and the MP3 export was completed in less than a minute! I checked the exported MP3 to make sure it was actually the entire lecture, and it was just fine.

Now, we’re on a roll. I pulled up the next pending lecture to process. I did everything exactly the same. Again, Audacity started grinding along, with the time remaining going up and up; but then, suddenly, at about the one minute mark, the progress bar raced to the end, and the export was finished.

My color today is meatloaf dense. Yesterday, the progress bar didn’t do that sudden burst. Today it is. Yesterday, the progress bar was accurately estimating time to completion of over an hour. Today, that progress bar is way overestimating the time to completion.

As long as I’m not actually waiting over an hour to export a file, I don’t really care whether or not the progress bar is right, so the main problem might have been resolved.

I thank you for your help.

Are you using an external hard drive?

There is an item in the 2.1.2 Release Notes:

When exporting a longer mix and one or more tracks are much shorter than the others, the export progress bar will appear to show no progress and “remaining time” will increase continually. However the file will export normally in reasonable time if you wait for the progress dialogue to close.

I believe you are experiencing that bug, which is now fixed in our source code and so will be fixed in the next 2.1.3 release of Audacity.


I am surprised by this as I part of the QA testing I do for new releases is a set of timing tests on a one hour project.

One of the things I test is a set of exports, including export to MP3, and I recorded no signifaction improvement or deterioration 2.1.2 versus 2.1.3.

I also export sever times a week one hour and two hour shows to Mp3 and these exports have not increased in time for me.

I am running Windows 10 (migrated from W7).