Audacity Forum

Okay, so the built-in mic probably does have a different latency setting than the line input -- which seems to have none. I did the test with the click track and the loop back cable going from the line out to the line in jack.. Maybe I should try the click track test and let the sound from the computer's speaker get picked up y the built-in mic.

Of course, I could aways resign myself to just time-shifting the vocal track after the fact ...

Aha, I seem to be the 2nd person in the world to have this problem. MacBook Pro 2012, OS X 10.8.5, using the built-in audio. Using a loopback cable the latency inconsistency is of the order of 50ms; using the built-in microphone it's all over the place. Might be a couple of 10s of ms time, then 200ms the next.

All very odd! Anyone else hit this?

Had a random thought when I heard the usual click which the audio card seems to make when it powers up and down. I wonder if the time it takes for the card to power up is affecting the results?

gpk wrote:All very odd! Anyone else hit this?

As you gathered there probably isn't much to be done about this apart from the obvious idea of shutting down as many other programs as possible and stopping Mac doing Time Machine backups, contacting network servers and whatever else it does from time to time.

gpk wrote:Had a random thought when I heard the usual click which the audio card seems to make when it powers up and down. I wonder if the time it takes for the card to power up is affecting the results?

To test your theory about initialisation, if you record for two seconds, stop, then immediately record again, do you hear the click when starting the second recording?

If so, might Macbooks turn off the audio subsystem after 20 seconds of inactivity be anything to do with this? If so, you could try Antipop linked to in that "makeuseof" Article.


Gale