Dealing with very large audio files

Over the weekend I recorded about 5 hours of audio on two different field recorders.

Both recorders broke the audio data up into I think 4 GiB chunks. What is the easiest way to get those files back together in a single Audacity clip? I would like to do that with the files from both recorders so I will only have 2 clips to synchronize.

I used a “clicker” at the beginning and at the end to synchronize the two recordings. If it turns out that the two clips drift apart over time, what formula do I use to slow down the faster one and make them match?

WAV files are limited to 4GB (because of a 32-bit “data size” field in the header).

I don’t know of any other format that has an “artificial” limit so after joining, export to another format.

I don’t know if this is the best way to join the tracks but you can “import” (rather than “open”) the 2nd track and drag it to the right. (Zoom-in to align.) The tracks will be “mixed” when you export, but of course if they don’t overlap they won’t actually mix.

You can use the Change Speed and Pitch effect to adjust the speed and you can enter a new length. (If the speed is off the pitch will also be off and this will make them match, but you won’t notice the pitch difference/error unless it’s way-off.)

What he said. That’s how my perfect-quality recorders work.

Reading that three times… Both recorders ran at the same time? What’s the work? Is the final show going to be a synchronized mix, or edited down to Left and Right Stereo?

This generally works out better if we can visualize the completed show in our heads.

Koz

It was a conference with the first half training and the second half a hands-on experience. Most of the time the two recorders were in the same room, though I expect different voices picked up from whomever was closest at the time, which should prove interesting.

Ultimately I will edit it down to just the best parts.

What I ended up doing was concatenating the three files from the first recorder by opening the first one, adding the second and third files, then aligning them end to end and “mixing” then down to one clip, even though there really wasn’t any mixing involved. Then I opened a second copy of Audacity and did the same thing with the files from the second field recorder.

I didn’t want to drag any files into place because I feared I wouldn’t get them exact. Aligning end to end did that for me.

Then I opened a third copy of Audacity and pasted the clips from the first two copies into it and synchronized them. Amazingly, I didn’t have to stretch or shrink either clip. They stayed in sync from beginning to end.

One more thing…

In every Windows program I can remember using, if you have an instance of it running and you hold the shift key down while opening, it will allow you to keep one running and open a new instance.

Not Audacity.

If you have an instance of Audacity and you hold the shift key down to open another, it moves the focus to the already running instance.

The only way I could figure out to start a second instance of Audacity was to open an existing file using Open With > Audacity, then delete the clip.