Distorted playback...sometimes

Hi there: I’m using version 2.3.2 in OS 10.15.6 and am finding that if I play back a song using Audacity it sounds fine but if I play back the exact same file using Apple Music the loudest bits get some crackly distortion–sometimes, not always. I tried reducing the playback volume in Music but that made no difference, the crackle only got softer. Not all loud parts get distorted, only certain ones. Any theories on why this would happen? Thanks in advance!

Do you have [u]clipping[/u]?

Are you mixing? Mixing is done by summation so the exported mix can clip even if the separate files don’t.

if I play back a song using Audacity it sounds fine but if I play back the exact same file using Apple Music the loudest bits get some crackly distortion

Audacity uses floating-point temporarily/internally so Audacity itself can go over 0dB without clipping. You’ll clip your digital-to-analog converter if you play-back at “full digital volume” but you might not hear it if you play at lower volume.

If your audio goes over 0dB and you export as “regular WAV”, the file will be permanently clipped (distorted). Some formats can go over 0dB but it’s “bad practice” to make such a file because the listener’s DAC can clip when the file is played.

Audacity does not find clipping in the file I’m working on, and the file is not mixed, it’s a straight recording via a Zoom H2N recorder. I normalize the WAV file to boost levels to the preferred max (-3db is the top limit I set). If I then export the result as a 256k MP3 or as a regular WAV I get the same result.

Are you recording audiobook chapters?

Are you using Audacity Audiobook Mastering?


This is the abbreviated version.

Screen Shot 2020-09-17 at 8.58.23 AM.png
If you’re recording at home, it’s good to use all three of the steps. The first one is a rumble filter and its job is to get rid of very low pitch sounds that can cause troubles even if you can’t hear them. Many home microphones have this problem.


Select, export WAV, and post ten seconds of a passage that causes troubles.

Scroll down from a forum text window > Attachments > Add Files.


The issue happens around 7-8 seconds in.

It’s rich in overtones and slightly higher volume right there, but I don’t hear anything wrong.

Can you play it in QuickTime?


There is one. There is high pitched, crisp sound really close to the digitizing limit of 44100.

Apply Effect > Low Pass filter.

Screen Shot 2020-09-17 at 9.59.33 AM.png
See what happens.


Haven’t tried QuickTime, as I noted the problem seems to be within Apple Music specifically…I’ll check QT.

Sounds fine in QT also. Could you please explain the tool you posted? Low-pass filter, I think it was. I am not at all an expert in any of this, just an occasional hobbyist user.

A digitizing system has to assign numbers to every note you perform if we have any hope of playing the notes back later. The WAV you posted has some high pitched, crisp sound energy dangerously close to the digitizing limit and the recorder might have trouble making a proper sound file, or worse, the digitizer guesses at it and different playback systems may have trouble playing it back. At worse case, the playback can create audible trash that didn’t used to be there in the original show at all.

I reduced the treble in the performance very slightly. I expect some 9-year old girls in the audience might notice the change. The change will go right by men and any girls older than that.

See what happens. I’m on the edge of my seat.


Sorry to have to ask, but where’s your version? I don’t see it attached inside your response.

where’s your version?

[Puzzled Puppy Look]

I don’t have a version. I applied that single filter to the sound file you post on the forum and it appeared to solve what I perceive to be the slight conflict. I didn’t keep the second file and I couldn’t get the original to break.

I posted how I did it.

Select a sound file you know breaks with the Select button on the left. Effect > Low Pass Filter: 18000, 24dB > OK. Export it with a slightly different name so you can find it later.

See if the new one breaks.


Oh, I see, sorry for my density. Same thing happened in Apple Music and nowhere else so I suspect the issue has to do with the Music app, not the file itself. The end use of the file will not be with Music anyway so I am hoping for the best, but I really appreciate your input! Thank you.

Same thing happened in Apple Music

You applied the filter and the music is still distorted?