Crackly Recording

I’ve been using Audacity 2.4.2. for several months now to record/submit voice auditions for various gigs. Recently - either im just noticing it now and it’s always been there, or something has changed - I’m noticing a ‘crackle’ in the recorded audio. I’ve attached a sample of me reading ‘Nemesis’ here to demonstrate what im talking about.

Initially, I thought it was a hardware gain issue(from the iD4) but after fussing with it for a few hours I can reproduce across different gain levels. Fussing with sample rates yielded results, but never eliminated what I was hearing.

Also, Ive attached a generated support RAR which may help, as Im certain the issue lies somewhere with a driver or software setting.

Equipment being used:
Windows 10
Audient iD4 pre-amp(XLR to Mic, USB-C to PC)
Rode NT-1A microphone
Kaotica Eyeball noise isolation

I’ve tried matching bit rates/sample rates(on both devices through Windows’ Device Manager, and via Device Preferences in Audacity), reducing the latency buffer length/latency compensation to 0ms and im still getting the effect.

Any thoughts? (14.1 KB)

This has eaten my whole day lol. Things ive tried:

  • uninstalling/reinstalling audacity (nope)
  • uninstalling/reinstalling the audient id4 driver (nada)
  • installing asio4all (didnt notice anything)
  • nonstop tweaking of sample hz and sample bit rate across both device manager and audacity (mixed results)
  • opening old projects and listening for the error(it does not exist)
  • identifying bitrate hz of old projects (384,000 mixed down to 48,000 on export)
  • re-exporting those old projects to see if the error is reproduceable that way(it is not)
  • nonstop tweaking of buffer size and latency compensation parameters (30/30 worked well, as did 0/0 but anything else made it worse. Default if 100/-130 is…fine)

Until i had a breakthrough and used the Microsoft Voice Recorder app on Win10 to record through the mic, and the issue was reproduceable there. I then tried out a headset mic that is a direct USB into the PC, and that had no issues either. Opening Audacity, using the headset mic gave me clear(if not the highest-quality) results.

So the issue is somewhere between the microphone itself, and the id4 amp/the USB connecting the amp to the PC. Ill do some hardware testing next.

I recognize this is an audacity forum and this has now moved outside of that realm, but if anyone has had any experience with fixing things like this, let me know!

It’s skipping : tiny pieces are missing, there is usually a discontinuity where that has happened …

this definitely points towards a more OS-based issue combined with the results from testing today.

However, even after implementing the changes within the linked article, and chasing down some additional windows 10 specific audio issues, im still having the stuttering crop up during recording.

im unsure why there’s an issue with writing the data; the computer in question is a moderate high-end gaming rig, plenty of RAM and CPU cores. Temporary file storage is assigned to a 1tb NVMe drive.

weirdly, a recording from a month ago sounds clear as crystal and I cant identify what has changed that would cause the issue.

Update: patched the affected mic and id4 pre-amp into a different windows 10 PC, and they work just fine. Error is within windows itself.

Now, how to fix that…

If you’re attempting to record at 384kHz, that can cause skipping: 48kHz is plenty.
(if you tried eating at 8x normal speed you’d occasionally choke on the food).

Standard Audacity doesn’t speak ASIO, but Audacity’s free competitor OCENaudio does.

IIRC Audacity only uses one core.

Update: Installed the Feature update to Windows 10, version 21H2 via WIndows Update, and switched the audio host over to MME from WindowsDirectsound. Issue is gone.

Interestingly, during my initial explorations, I tried using MME but it was kicking me back an error and not recording. Likely the issue was originating in the same place that was giving me errors when I tried to use that Audio host. Either way, its fixed for now.