I am filming an audition with a clarinetist who is standing fairly still while playing several pieces for an audition and I’m also recording it separately through Audacity to allow me to use a much better microphone.
The video camera is set to film at a 29.97 framerate. Is there a way to set up Audacity so that it will match that rate prior to recording?
Assuming you are double-recording the audio, clap your hands at the beginning so you can sync the Audacity sounds with your video editor. Your video editor should be capable of displaying both audio tracks and it should allow you to move the Audacity track. (Then of course you can delete or mute the audio from your video camera and edit-out the clap.)
Every device has its own clock (oscillator) and after a period of time the camera and soundcard (or interface) will drift out-of-sync.(1) Typically there won’t be a noticeable difference over a few minutes but with a “concert length” or “movie length” recording you might get “lip sync” errors by the end. And some consumer soundcards can be worse, and some have speed variations that are bad enough to cause musical-pitch problems. (2)
With video, the audio sample rate is usually 48kHz, but that’s not super-important either. But if you record at 48kHz you can avoid re-sampling with your video editor.
(1) Pros use a super-accurate master clock (AKA “word clock”) and audio/video equipment that can accept an external clock. The audio from multiple devices is matched to the exact sample (i.e. 48, 000 samples per second) and multiple cameras are matched to the exact frame.
(2) Normally you don’t notice it because when you play an audio file (MP3, etc.) everything in the recording stays in-pitch with itself. There also won’t be a pitch-shift if you record and play-back on the same soundcard. But musicians trying to play-along will notice it, and it often creates problems when collaborating with other remote musicians all with their own equipment.
Thanks for your reply. I am clapping at the beginning already but the audio begins to drift out of sync. I can fix it after the fact, but there is a bit of a pitch change. I was hoping there was a setting to use in Audacity that I could set ahead of time.
How are you fixing it after the fact, and by how much do you have to fix it (as a percentage difference)? If it’s a speed change of less than 0.6% (10 cents), you shouldn’t notice the pitch change. If it’s a small sample clock error (as DVDdoug mentioned), unless you’re using very low-end or faulty recording equipment, I’d expect it to be less than say 500 ppm (parts per million), or 0.0005%, far too small to notice a pitch change, but enough to notice syncing problems after some minutes.
On the other hand, if you are recording at 44.1kHz and playing back at 48kHz, or vice versa, that’s a pitch change of 8.8%, clearly noticeable. It’ll drift out of sync very quickly too.
Effect → Pitch and Tempo → Change Tempo can change-correct the speed while retaining pitch. But it’s a “complicated” process and audio quality MIGHT be affected so you’ll just have to try it.
Or if you are using your regular soundcard and this not a one-time thing, you might want to get an Audio Interface and a “studio” microphone. (Audio interfaces work with stage/studio mics with balanced XLR connections and they are not compatible with (unbalanced) “computer mics”.)