First, convert less than you think
The instinct when discovering an alternative tuning is to convert everything. This is almost always a mistake, and not only because of the time involved.
A converted library is a second copy of everything, doubling storage and creating a permanent question about which version any given file is. Meanwhile most of a typical library is music you rarely play.
A better approach: convert the twenty or thirty pieces you actually listen to when you want to relax, focus or sleep. That is where the change is worth having. You can always convert more later; undoing a sprawling half-organised duplicate library is much harder.
Which material benefits most
Sustained, sparse, acoustic material â piano, guitar, strings, ambient, choral â takes pitch shifting cleanly and is where a warmer character is most noticeable. Dense percussive mixes show more artefacts and less benefit. Start with the former.
Protect the originals first
Before converting anything, make sure your source files are backed up somewhere the conversion process cannot touch. This is the one step that turns a bad afternoon into a minor inconvenience.
Work on copies in a separate working folder. Never point a conversion process at your only copy of anything.
A workflow that scales
1. Set up folders before you start
Decide the structure first, because renaming several hundred files afterwards is miserable:
Music/ originals/ (untouched, backed up) to-convert/ (working copies) converted-432/ (results)
2. Work in small batches
Ten to twenty tracks at a time. Small batches mean a mistake costs you ten files rather than four hundred, and you can check the first few results before committing further effort.
3. Establish a naming convention immediately
Append a marker to every converted file â Artist - Title [432].mp3. Without this, converted and original files become indistinguishable once they leave their folders, and you will eventually convert something twice.
4. Check the first few by ear
Listen to the beginning, middle and end of the first two or three results. Verify the duration matches the original, the file plays to the end, and nothing sounds obviously wrong. Catching a problem at track three is much better than at track three hundred.
5. Fix the metadata
Conversion usually strips or mangles tags â artist, album, artwork, track numbers. Without tags your music player will file everything under "Unknown Artist", which makes a converted library nearly unusable.
Tools such as MusicBrainz Picard, Mp3tag (Windows) or Kid3 (cross-platform) can restore tags in bulk. Adding a marker such as 432Hz to the comment or album field makes converted files easy to filter in any player.
The mistake to avoid above all others
Never convert a file that has already been converted. It does not take you further and it compounds both the pitch shift and the encoding loss. A clear naming convention is what prevents this.
When to use a desktop tool instead
Our converter is built for convenience: one file at a time, no account, quick results, stereo MP3 out. For a handful of listening copies that is exactly right.
For a large library, or where you need a lossless result, a desktop tool is the better instrument. Audacity is free and cross-platform; its Change Pitch effect accepts a value in cents, so â31.8 cents gives you the 440-to-432 shift, and it can apply the same effect across many files via chains. Users comfortable with a command line can script SoX or FFmpeg to process a whole folder and write lossless output.
There is no disloyalty in this recommendation. Using the right tool for the scale of the job is what gets you a library you are happy with.
Storage and expectations
Budget roughly 1.3 MB per minute of audio. Two hundred four-minute tracks come to something under a gigabyte â trivial on a computer, less so on a phone with limited space.
Finally, be prepared for the possibility that you prefer some tracks unconverted. That is a legitimate outcome. Keeping both versions of your favourites and choosing by mood is a perfectly reasonable end state, and a good reason to have kept those originals safe.
When you want to start, our 432 Hz converter is free and needs no account.