How-to: sfz



1) What is sfz?

Sfz is a plain text file format that stores instrument data for software synthesizers. See full Wikipedia’s page

2) Can I play sfz soundfonts on Mac/Windows?

Many programs support sfz, for example Sforzando

3) Are sfz soundfonts better that other soundfonts?

No, the final quality of a soundfont is determined by the quality of the job done by the sound designer who recorded the samples. Although we may say that sfz is a very flexible and open format, and has advanced features that make it compete with some well known commercial formats

4) Why another soundfont format? I have Komplete and I’m done with it…

Komplete is a proprietary commercial solution. To play such samples you need their proprietary player, Kontakt Player. If you think about it, you bought their samples but you don’t own them: you cannot import your samples files in Audacity and edit them. Sfz is an open format, that means that you can use the program you want to play them, the only requirement is that this program needs to support sfz format. In sfz format the individual samples are just wav files that you can edit with the program of your choice. You have total control over the samples you bought and you have no limits for your creativity.

More on sfz?

When you refer to a soundfont, you refer to a file that can be loaded by your favourite sample player. A soundfont/instrument in sfz format is a directory with this structure:

├── B3.wav
├── B4.wav
├── B5.wav
├── Bb1.wav
├── Bb2.wav
├── D2.wav
├── D3.wav
├── Eb4.wav
├── Eb5.wav
├── Eb6.wav
├── G3.wav
├── G4.wav
├── G5.wav
├── Gb2.wav
├── harpsichord.sfz
└── license.txt

you have a list of wav files that are actually the samples (i.e. a single notes of a piano recorded from attack to end of decay) and a file with .sfz extension that is where the magic happens. This file is a map between notes and samples and is a structured document, like html for example, with regions identified by specific tags and syntax. Let’s see the content of harpsichord.sfz:

<group> ampeg_release=.2 ampeg_sustain=.01 ampeg_decay=60
<region> sample=Bb1.wav pitch_keycenter=a#1 hikey=c2
<region> sample=D2.wav lokey=c#2 pitch_keycenter=d2 hikey=d#2
<region> sample=Gb2.wav lokey=e2 pitch_keycenter=f#2 hikey=g2
<region> sample=Bb2.wav lokey=g#2 pitch_keycenter=a#2 hikey=b2
<region> sample=D3.wav lokey=c3 pitch_keycenter=d3 hikey=e3
<region> sample=G3.wav lokey=f3 pitch_keycenter=g3 hikey=g#3
<region> sample=B3.wav lokey=a3 pitch_keycenter=b3 hikey=c4
<region> sample=Eb4.wav lokey=c#4 pitch_keycenter=d#4 hikey=e4
<region> sample=G4.wav lokey=f4 pitch_keycenter=g4 hikey=g#4
<region> sample=B4.wav lokey=a4 pitch_keycenter=b4 hikey=c5
<region> sample=Eb5.wav lokey=c#5 pitch_keycenter=d#5 hikey=e5
<region> sample=G5.wav lokey=f5 pitch_keycenter=g5 hikey=g#5
<region> sample=B5.wav lokey=a5 pitch_keycenter=b5 hikey=c6


  • <group> parameters that affect multiple regions: in this soundfont we have global release, sustain and decay
  • <region> since a single sample can be mapped to multiple notes, they are called regions more than notes or sounds.

This is the pattern that maps the sample to a note:

  • sample= wav or flac file
  • key= or lokey= hikey= pitch_keycenter= note

Okay thanks for the theory, how can I create my soundfonts?

I prefer to edit .sfz files by hand, since I’ve discovered the sfz sintax is very simple and you can have a working soundfont by using two-three tags. But full featured edit softwares do exist for sfz, see for example Polyphone. Actually to realize my soundfonts I’m using some custom made scripts. I may publish them in future, if interested write me a message.

Where I can listen to your samples?

I use to include my samples into Aida DSP OS releases. To own my samples you can buy the board.

Where I can download some sfz samples?

  1. Free (may require registration)
    • google is your friend
  2. Non-free
    • your favourite samples store could already have samples in sfz format, check it out!

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