Long time Audacity User but first-time poster to this forum. I’ve been using Audacity to produce an Audio-Drama/Podcast for the past 5 years with no problems at all (quite an accomplishment IMO - thanks Audacity Team!). Unfortunately, my luck has run out and I’m in need of a little help.
THE PROBLEM: Audio playback in Audacity of my current project produces distorted audio. It’s a jagged, staticky, and choppy audio making playback unusable. It’s brought my production to a halt since I can’t get rid of it. Yosemite appears to be the culprit as that is the only change to my system recently. I’m stuck with Yosemite for work-related reasons.
PROBLEM DETAILS: With a lot of trial and error, I’ve actually found ways to manipulate the problem (just not eliminate it).
The distortion never occurs upon my first launch and play of an Audacity project. Everything plays just fine. However, the moment I press stop and play the project a second time, the audio playback is corrupted. When distortion appears, I can quit and relaunch Audacity for a distortion free listen… but as described, that only works once and it returns.
I noticed that the distortion will disappear only when playing certain tracks (sadly, the bulk of my tracks). I discovered that my 44100Hz tracks are the ones that experience this audio distortion. But as soon as a 48000Hz track plays (solo or overlapping), all distortion goes away. Once that 48000Hz track ends, the distortion returns. In fact, I could eliminate the distortion entirely by always having a 48000Hz track playing. I had hoped doing so and then muting the track might be a workable fix but the moment the track is muted, the distortion will return to all other audio as well.
MY SETUP: Macbook Pro 13 (2012). Intel Core i7 2.9 GHz, 8GB RAM, Yosemite 10.10.1. 150GB of free SSD disc space. I’ve experienced this problem both with Audacity 2.06 and 2.05.
I’m not the most tech-savvy person but certainly get by. I’m hoping that perhaps someone might recognize this issue and have a relatively simply fix or work around. I do have the ability to switch to Audacity on a PC if this is a Yosemite issue with no fix available. But that isn’t the most convenient or ideal solution… just a last resort so my production can resume.
You didn’t say what sound device you are playing to or recording from. If it’s an external USB or Firewire device and 48000 Hz makes it behave, open /Applications/Utilities/Audio MIDI Setup and set the input and output to a 48000 Hz choice.
Open Audacity > Preferences…, Quality section and make 48000 Hz the Default Sample Rate. Then new projects will be that rate.
If you import a first file into the project and that file has a 44100 Hz sample rate, that will change the project rate to 44100 Hz. If that happens, or if your tracks are at different sample rates, change the project rate bottom left to 48000 Hz if necessary, then Tracks > Resample… and click OK. This will resample all tracks to the project rate.
If that does not help, experiment with different “Audio to buffer” settings in the “Recording” section of Audacity’s Recording Preferences. That affects playback too.
But as Koz said, Audacity does not yet officially support Yosemite.
Thank you for the added suggestions. I will give those a try. I think they’re right on track…
I’ve made a bit of progress on my own as well. First of all, this doesn’t seem to be a Yosemite problem after all. I switched to a different machine using Mavericks and experienced the exact same problem. I also switched back to Audacity 2.05 and still the same problem. So, I’m not sure what has triggered this issue since I never experienced it before but it doesn’t appear limited to Yosemite.
On a hunch, I decided to take OUT the 48000 track in my project that appeared to be “fixing” the problem. Sure enough, the moment I did that the problem disappeared and I could not reproduce the audio distortion at all. For some reason, having a mix of 48000 and 41000 seems to be what’s causing the audio distortion. Again, why I haven’t experienced this sooner (I’m re-using tracks from earlier projects) is still a mystery.
So, with that said, I’m actually hopeful that your suggestions above and eliminating the mixed tracks will resolve the problem. I’ll update this post once I’ve worked with this a bit with any info helpful to others for future reference.