Running Audacity 2.4.2 on a fairly new Mac, Mojave 10.14.6.
I have debilitating latency issues. I am attempting to record music, so, any significant latency makes it impossible.
I ran the latency test recommended by Audacity, which entails generating a rhythm track then recording with that track playing then adjusting latency compensation until they sync. This went fine, but when I tried recording a new track with a USB external mic, what happened is truly strange to my mind. The initial beat was almost a full second late, but by neat 8 or so it was in sync!
Also, for unknown reasons, after running the latency operation described above, Audacity no longer monitors input. It does record and plays back input sound, just won’t monitor any more. No idea why or how to fix that.
Try lowering the [u]Latency/Buffer Length[/u] setting. That may not work, and you’ll get glitching/dropouts if the buffer is too small but it’s worth a try.
Of course, that won’t work with a different tempo.
…IMO - The best solution is to use an audio interface with zero-latency direct-hardware monitoring. (Your USB mic won’t work with an audio interface and they don’t work with “computer mics” either.) Some “USB podcast mics” have a headphone jack and that same zero-latency feature. Or a mixer, etc., where the monitoring path doesn’t go through the computer. You can still monitor the backing-track from the computer and any latency can be compensated-for later during mixing.
When I overdub I use a slightly different system that seems to work for me on Windows:
Create backing track.
Select overdub ON.
Select software playthrough (monitoring) OFF.
Plug in headphones.
Shift-Record
Now I do not get real-time feedback of my recording, but I have done this enough times that I know what I sound like.
I watch the wave forms to confirm that my recording is OK.
Listening to your live input without any delay requires hardware that has “zero latency monitoring”.
Recording a new track so that it lines up correctly with other tracks should work with pretty much any sound card, so long as you only need to listen to the previously recorded tracks and not the “live” input.
