What you should know
An audio file is a series of samples, described at a given rate — 44,100 times per second for a CD — and across one or more channels. Its size depends on that definition and on the chosen compression mode.
Two families oppose each other: lossless formats (WAV, FLAC) return the signal exactly, while lossy formats (MP3, AAC, OGG) remove barely audible detail to lighten the file sharply. The choice commits the quality of the whole chain.
Strengths
- Lossless formats preserve the signal for archiving and editing
- Lossy formats cut size by a factor of five to ten
- Bitrate is chosen for the use: speech, music, archiving
- Metadata organises music libraries
Limitations to know
- Lossy compression is irreversible
- Converting one lossy format to another compounds degradation
- Old hardware does not always read recent formats
- The size gain depends mostly on the source, not the target format
When to use it
Archive in WAV or FLAC, deliver in MP3 or AAC, reserve OGG for free projects. The rule that outranks all others: never re-encode a lossy format if you can start from the original source.
Quality, size and compatibility
Final quality is capped by the source. A poorly recorded WAV stays poor; an MP3 converted to FLAC recovers nothing. Conversely, a good recording converted once at 192 kbps satisfies most listening.
Frequently asked questions
- Can converting an MP3 improve quality?
- No. The loss is final. Changing format only moves the same information around, sometimes adding new degradation.
- Which bitrate is enough for music?
- 192 kbps suits everyday listening in MP3 or AAC; 320 kbps for demanding headphones. Below 128 kbps the difference becomes audible.