“Conversion” can mean three very different things: changing the container, decoding and re-encoding losslessly, or creating a lossy delivery file. Only the third must discard information. A careful workflow can change WAV to FLAC—or FLAC to ALAC—while preserving every decoded sample.
Know whether the destination is lossless
| Conversion | Can audio remain identical? | Important condition |
|---|---|---|
| WAV to FLAC | Yes | Do not change sample format or process the signal |
| FLAC to ALAC | Yes | Preserve sample rate, bit depth and channels |
| FLAC to MP3 | No | Choose a suitable bitrate and encode once |
| MP3 to WAV | No restoration | WAV preserves the decoded MP3, not the missing original |
| MP3 to MP3 | No | A second lossy generation is created |
Preserve sample rate and bit depth
If a 24-bit/48 kHz master is converted to 16-bit/44.1 kHz, the file is no longer sample-identical even if the codec is FLAC. That may be a valid delivery requirement, but it is processing, not a transparent format swap. Keep the native settings for the archive and create a separate delivery version.
Changing sample rate requires a resampling filter. Good resampling can be transparent, but unnecessary conversions add risk. Choose one project rate early and avoid bouncing between 44.1 and 48 kHz.
Use dithering only when reducing bit depth
Dither is very low-level noise used to make quantization error less correlated with the signal when moving to a lower bit depth. Apply it once at the final reduction—typically 24-bit to 16-bit—not on every export. Do not add it when merely moving between lossless containers at the same depth.
Prevent clipping and accidental processing
Some conversion tools normalize, boost volume, change channels or apply effects by default. Disable those options for a transparent conversion. If the input contains inter-sample peaks, a lossy encoder can produce a decoded peak above full scale even when the source meter does not. Leave a little headroom for delivery encodes and audition the result.
A quality-preserving workflow
- Identify the real source. A file called WAV may have originated from MP3.
- Keep an untouched backup.
- Select a lossless destination for masters: FLAC, ALAC or WAV.
- Match the original sample rate, bit depth and channel count.
- Turn off normalization, effects and trimming unless intentionally required.
- Convert and compare duration, technical properties and, when possible, decoded checksums.
- Create MP3/AAC delivery copies from the master only after editing is complete.
Can quality lost to MP3 be recovered?
No conversion can infer the exact information a lossy encoder removed. AI restoration or enhancement may produce a more pleasing result, but it creates new content rather than recovering the original samples. Converting MP3 to FLAC is useful only when a lossless container is required for the next stage; it does not upgrade fidelity.
Archive and delivery should be separate
A resilient audio library keeps one authoritative lossless file, then derives device-specific copies. When a platform changes its requirements, you return to the master instead of transcoding yesterday’s delivery encode. That single habit prevents most avoidable generation loss.