Converting M4A to WAV for editing

[Sass]

So, I asked someone to record an audio of a live music performance for me, but they recorded in M4A. I want to chop up the audio and create tracks of each song, then export as both m4a and WAV. I figure that to preserve quality, I should probably convert to WAV or some other lossless file type first before editing.

MediaInfo output

Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (mp42/isom)
File size : 28.4 MiB
Duration : 1 h 2 min
Overall bit rate mode : Constant
Overall bit rate : 63.9 kb/s
Encoded date : UTC 2022-10-12 01:28:32
Tagged date : UTC 2022-10-12 01:28:32

Audio
ID : 1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 1 h 2 min
Bit rate mode : Constant
Bit rate : 64.0 kb/s
Channel(s) : 1 channel
Channel layout : C
Sampling rate : 22.05 kHz
Frame rate : 21.533 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 28.0 MiB (99%)
Language : English

My question is, what settings should I use when exporting? I think I should use a 22050 Hz sample rate, because that’s already what the M4A is (see MediaInfo). But what about the Encoding? I am an amateur and I don’t know what I’m doing.

Please help.

Thanks!

[romontschun]

If you only want to separate the songs, I’d open the m4a in Audacity (yes, that works), then set the song labels and export again using export multiple according to labels. Depending on what you are using it for, I’d use quality settings which were present before.

There is no need to convert m4a to something “better” - because what is not there cannot be reconstructed - and when exporting as m4a or mp3 again, another bits may be lost.

[Sass]

Sorry I should have mentioned, I’m deleting speech at the beginning and end of the audio to preserve privacy, then sending it off to someone else to track into multiple files using Audacity. Wouldn’t this mean that after deleting speech, I’d export to m4a (quality loss), then the person I’m sending it to would also export that into m4a tracks, resulting in double quality loss?

That’s why I wanted to convert to WAV first.

[DVDdoug]

It’s OK to use the same format. Or you can export as WAV or FLAC. It also depends on what final format you want or need.

There’s no need to convert to WAV first. Audacity (or any regular audio editor) decompresses the audio when you open it. If you export in a lossy format you are going through another generation of lossy compression.

M4A (AAC/MP4) is lossy compression BUT Unlike MP3 “damage” does not accumulate. 100-pass recompression test