Chosen Hertz
Retunes a recording to A=432, C=528, or any reference pitch you set — the way a tape machine does it, with no time-stretching in the signal path.
1. Load a file
Everything runs on your device. Nothing is uploaded, and the audio is never re-encoded to a lossy format.
2. Pick a reference pitch
3. Convert
Pitch and speed move together, like slowing a tape. Nothing is rebuilt, so this is the cleanest option.
4. Listen and save
How it works: each output sample is rebuilt from the source with a 32-tap Kaiser-windowed sinc interpolator, which is the same resampling maths a mastering-grade sample-rate converter uses. Pitch and speed move together, exactly as they would if you slowed the tape down. No phase vocoder touches the audio, so there is nothing to smear transients or add the warble you hear from typical online converters.
Peaks are measured after conversion. If interpolation overshoots 0 dBFS the file is attenuated just enough to stop it clipping, and the amount is reported.