No!!! Mix and render now broken in 1.3.14!!

Hi lads, thanks for a fabulous app, I really love your work.

I have a request after trying 1.3.14 though, as it contains what amounts to a step backwards for me in one area.

After completing a project I always export all my tracks as high-quality MP3s, to serve as “master tapes”. This way regardless of format changes to Audacity files, or directory structure changes on my computer, or whatever, I will always be able to load back in (“import audio”) and remix or upgrade if desired in the future.

It relies on all the tracks being of the same length (or at least starting from time 0) so when they’re loaded back in they are synchronized properly.

I loved mix and render for this, because it front-pads “punch-in” tracks perfectly, and takes out that mysterious pre-zero sound that fouls up the master track timing as well.
Then “export multiple” gives a lovely set of master tracks.

Until 1.3.14 :^(

“Mix and Render now preserves clip length by not rendering white space between time zero and first audio, and preserves audio before time zero. To retain silence before the audio starts, generate silence after render.”

This is a big downgrade for me!!!

If this has to be so, can we fix “export multiple” please, to front-pad the white space, and line everything up so that pre-zero audio doesn’t de-synchronize the tracks? Please? Otherwise I am stuck on 1.3.12…
Alternatively why not leave “mix and render” as it was?

Thanks for listening!


I just tested on 1.3.14 and the Release Candidate for 2.0 and Mix & Render is still there - it’s under the Tracks menu.


Wow, thanks for the quick reply Wax.

Yes I agree Mix and Render is still there, but it now functions differently to the previous version 1.3.12 (see quote from “new features” page for 1.3.14 above).

If you’ve recorded a track that doesn’t start at time 0 - and most of mine don’t - there seems now to be no way to export that track as part of an “export multiple” dump, and retain its position relative to other tracks. In the exported mp3 the blank space at the front is missing and the recorded audio appears right at the start of the mp3 for that track, so now bringing that audio back in is a hopeless task because the start time is lost.

Under 1.3.12 “Mix and render” made the new mixed tracks fully padded from time 0, so creating “master tapes” was a snap.

The change to “mix and render” functionality seems to make it impossible to save your project track-by-track as MP3s, at least in a way that can be used as master tracks. This to me is a very important step as having used Audacity for about 6 years I know that going back to old projects is a can be a chancy business, and also as we know projects are pretty bulky so the master tapes approach is a great way to archive them in a way that preserves the multi-track format.

Am I the only one who does this? Surely not? How does everyone else do it then?

As mentioned in the previous post, the “master tapes” functionality could be restored to 1.3.14 either by changing “mix and render” back, or updating “export multiple” with an option to preserve the clip positions within exported MP3s by padding (pre-zero audio would need to be handled as well).

Thanks for reading!

I don’t think the complaint is that Mix & Render has gone. I think the complaint is that it behaves significantly differently. Having never used it I cannot comment on whether it has changed its behaviour. However, I would make the following observation: saving to MP3 and then at a future date re-importing and doing more work is going to produce significantly degraded audio. Far better to save as WAV for your master copies. Better still, save the Audacity project. That will preserve all the synchronised positions and everything else.


I understand about the degradation with MP3 but I am using very high bitrate and I honestly can’t tell the diffrence from a WAV, even with high-end headphones. Plus, if you heard me sing you would understand as well.

Nevertheless even if I did decide to archive with WAVs rather than MP3s, exactly the same comments I made above still apply. It’s the same command, export multiple. There are heaps of other format options available too including other lossless formats. I assume they all treat leading blank space in a track the same way.

So going to WAV wouldn’t solve it I don’t think, unless the command works differently for other formats.

So, what’s that “export multiple” command for then, if it’s not to simplify archiving or possibly facilitate transfer to a different multi-track app?

For me archiving the whole audacity project is OK but it’s not as bulletproof as archiving in a widely importable format. Let’s be honest, the whole Audacity software project could die (unlikely but not impossible), or change storage formats and lose backwards compatibility, or who knows what. In the future I might want to load my old stuff into someone else’s preferred app, or I might have changed mixers myself for some reason (can’t think what reason that might be, but not impossible).

The chances of MP3s or WAVs not being readable in the future aren’t zero but they are lower. I already have problems loading old Audacity projects because the filenames inside the .aup files used to be stored as absolute not relative paths, and my directory structure (in fact the whole computer) has changed. If I want to re-load them now I have to temporarily re-create the old directory structure or they won’t load. Plus, I have had at various times other glitches when re-loading old projects - orphans and whatnot cropping up. The format doesn’t seem completely bulletproof in the face of the odd dropped bit. Who knows what problems might crop up in the future.

In fact I actually do keep the old zipped projects, but I don’t think that’s sufficient on its own and believe the “master tapes” discussed above are a very prudent backup.

But listen, thanks for the replies everyone, I really do appreciate having someone to talk to about this.

Thanks for your comments hknowlman, I’m very much in agreement with your point about moving project between multi-track environments (which could be a hardware multi-track device, a software DAW or another Audacity Project).

Picking up on a few specific points:

Probably the most common use of Export Multiple is “based on labels” for splitting CD / Vinyl recordings into tracks.
Another common use is for backing up the audio data in multi-track projects. In this case, lossless formats such as WAV or FLAC are preferable, but take up a lot of space. If during the course of working on a project, one audio clip is accidentally damaged, simply having a WAV format backup of that clip is sufficient to rescue the job. Including all of the silence in the tracks may significantly increase the size of exported WAV files, so there is a strong case for retaining the option of Multiple Export without including leading white-space. In fact there may be a case for an option to not include any white space and export each audio clip as a separate file.

If you have tracks that have leading white-space (they don’t start at time = 0), add a bit of “silence” to the beginning of the track.
To do this:

  • Select a section of white-space starting at time=0 (you can select this in multiple tracks at the same time by using the up/down cursor keys to move track focus, then use the ENTER key to toggle whether it is selected or not.
  • Generate > Silence

Now when you Export multiple the leading silence will be rendered and synchronisation will be preserved.

Audacity 1.3.x (and the soon to arrive 2.x version) have an option to copy all audio into the project so that the project is self contained. If you want to archive projects, it is highly recommended that you do this first. (more details here: )

I’m very much in favour of “An option to include leading silence in Exported tracks (this will enable exported tracks to be transferred to other multi-track environments and remain synchronised).”

Hey Steve, thanks for the tip on leading silence - at least I have a workaround now and don’t need to keep an old version installed.

I also would be very happy if the inclusion of leading silence was added as an option.

By the way, do you know what’s the story with that “pre-zero” audio? I sometimes end up with it, but never purposely, and I certainly never move whole tracks left so there might be pre-zero track parts.
Before “Mix and render” this was messing up exported-track synchronization as well, and from the release notes the new M&R might preserve it (sadly for me). Any ideas for a workaround there?

Again, thanks for the help!

Feature Requests already had 6 votes for an export preference “'Preserve start-time relative to time zero when exporting” so I added your vote (Steve) and that of hknowlman. The request now states “this is needed for exporting offset tracks for multi-track mixing elsewhere”.

The change to Mix and Render was done by a developer without any consultation (that I am aware of), which happens sometimes in open source. Sometimes also you get long discussions and nothing is ever decided. The previous Mix and Render behaviour where whitespace was rendered also annoyed some people, so rather than inconvenience one camp or the other it seems a preference would be the best solution.

If you get audio behind zero, it is probably because you recorded from time zero while another track was present. Audacity then applies a left-shift on the recorded tracks to allow for recording latency (the latency correction applied is configurable in the Recording Preferences).


and “Overdub” is enabled.

Trim off any “pre-zero” audio before exporting:

  • Ctrl+A (select All)
  • shift+HOME (move start of selection to time=0)
  • Ctrl+T (trim)

Thanks very much Gale and Steve, really appreciate your time and expertise.

Think I’m good as gold now, got a good workaround and know where it all stands.

Gotta love open source… try getting a responses that quickly out of a commercial developer!