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Audio and Sound Engines

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Orfeo has three sound engines: GM, a lightweight General MIDI synth that needs nothing extra; Studio, a realistic engine that plays soundfonts; and Native (beta), which plays the same soundfonts straight to your sound card for the shortest delay when you play a MIDI keyboard. All three work offline: GeneralUser GS, the default soundfont, comes with Orfeo, and only the extra soundfonts need the internet, once, to download. This page explains the difference, how to add more soundfonts and how to control the overall volume.

Master volume

The volume knob in the top bar sets the overall level for whichever engine is active. Drag it up or down; Orfeo remembers the position next time you start it. For per-instrument levels, use the  Console Mixer.

Choose a sound engine

GM

Studio

Native (beta)

Sound

Light, synthetic

Recorded instruments

Same as Studio

Start-up

Instant

A few seconds

A few seconds

Computer load

Very low

Higher on dense songs

Like Studio

Tone and Compressor

No

Yes

Yes

Key-to-sound delay

40 ms or more

40 ms or more

Under 10 ms

Best for

Editing, older PCs

Practice and listening

Playing a MIDI keyboard

  • Open Settings → Audio.
  • Under Sound engine, click GM, Studio or Native (beta).
  • The first time you choose Studio, a progress bar shows the soundfont loading. Orfeo remembers your choice.

GM is the default because it starts instantly. Studio is recommended as soon as you practise, because the expressive sound helps you hear phrasing. When you play along on a MIDI keyboard, Native (beta) answers fastest: choose it in Settings → Audio, and a connected keyboard switches it to Exclusive mode by itself.

Native engine (beta)

Normally every note Orfeo plays passes through Windows’ own sound mixer, which holds it back 40 ms or more. That’s enough to make a fast passage on a USB keyboard feel sticky, as if the piano answered late. The Native engine, new in Orfeo 1.5, plays the same soundfonts with Orfeo’s own engine, straight to your sound card. With a USB audio interface or headphones, what you play is heard in under 10 ms.

  • Low latency mode has two buttons under the engine. Shared goes through Windows, so a browser lesson or a video call keeps playing alongside Orfeo. Exclusive takes the whole sound card for Orfeo alone, for the shortest delay: other apps stay silent while Orfeo is open, and Orfeo warns you before it does this. If the sound card can’t be taken over, Orfeo shares it by itself and Settings → Audio says why. Under the engine buttons you also see your sound card, its mode with sample rate and buffer, and the latency.
  • A MIDI keyboard switches it to Exclusive. That’s when the delay matters. Plug a keyboard in and Native goes Exclusive; unplug the last one and it returns to Shared, so websites and videos keep playing. Choosing a mode by hand holds until the next plug or unplug, and every start of Orfeo begins from this rule. If you’d rather choose yourself, switch off the keyboard switch under Settings → MIDI Keyboard › Sound & Latency.
  • Wider sound: every instrument sits where the song puts it, two guitars left and right, strings to one side, reverb where the arrangement asks for it. Native mixes songs like Studio: every part is within about 1 dB of Studio in level and left–right placement, stereo instruments keep their width, and the reverb and chorus are the same.
  • Steady timing: songs, the metronome and the count-in run on the engine’s own clock, so the first note after a count-in lands exactly on the beat.

    • Native follows the Windows volume and mute on sound cards that have no volume control of their own, such as studio interfaces like the UAD Apollo and HDMI or DisplayPort monitors, and two limiters keep it from overloading any sound card. If an interface runs at a different sample rate than Windows reports, Orfeo times the card’s real speed during the first two seconds in Exclusive mode and matches it by itself, so the sound isn’t slowed down or distorted. If a card can’t be matched, Orfeo shares it through Windows and Settings → Audio says why.

    Studio and Native both play a song the way its arranger mixed it. Volume swells and fades in the file are played as written, tracks that share a MIDI channel share its volume, pan, reverb and chorus, and a part that changes instrument mid-song switches at the right moment, also when you change the instrument in the Tracks panel. The Console faders still turn a whole part up or down, swells included.

  • Survives unplugging: pull out your headphones or USB interface mid-song and the music carries on through the next sound card, and comes back when you plug it in again.
  • The Console Mixer, compressor, Auto-Level, Tone, chord previews and your MIDI Keyboard settings work just as with Studio, and you can switch engines in the middle of a song.

 Beta

The Native engine is new and has been tested on a handful of computers. If anything sounds wrong, switch back to Studio in Settings → Audio, then save the log from the Delay check and report a bug.

Soundfonts

A soundfont is a library of recorded instruments. The Studio engine plays one at a time, chosen in the Sound Fonts list in Settings → Audio.

Soundfont

Size

How you get it

GeneralUser GS

31 MB

Included with Orfeo, the default

FluidR3 GM

142 MB

Free download from the list

MuseScore General

38 MB

Free download from the list

Your own

Any

Import a .sf2 or .sf3 file

Download or remove a soundfont

  • Open the Sound Fonts list and click download next to FluidR3 GM or MuseScore General.
  • When the download finishes, Orfeo switches to it automatically. It’s kept on your PC, so you only download it once.
  • To switch between soundfonts you already have, pick one from the list.
  • To free up space, click remove next to a downloaded soundfont.

Import your own soundfont

  • Click Import your own .sf2/.sf3 under the Sound Fonts list.
  • Choose the file. Orfeo copies it, adds it to the list and switches to it.

Only import soundfonts you have the right to use. Remove an imported one with its remove button; your original file isn’t affected.

Already have a big file on your computer? You don’t have to use Import. Orfeo lists every .sf2 or .sf3 file it finds in its sound set folder, %APPDATA%\Orfeo\soundfonts; paste that into the Explorer address bar. Import does the same thing by copying the file there, so for a very large file, moving it in yourself saves the time and the second copy on disk.

Orfeo reads that folder when it starts, so restart Orfeo after moving the file in. It then appears in the Sound Fonts list, named after the file, with its size.

Microsoft Store version: Windows keeps Store apps’ folders elsewhere, at %LOCALAPPDATA%\Packages\<Orfeo’s package>\LocalCache\Roaming\Orfeo\soundfonts. If you installed from the Store, Import is simpler.

Very large sound sets: Studio and Native both load the whole file into memory when you select it. A sound set of a gigabyte or more takes a while to load and uses that much memory.

Output delay

Every sound card takes a moment to turn a note into sound. Orfeo measures that delay on your system, shows it next to Sound engine (for example output delay 40 ms) and holds back the lit keys and chord names by the same amount, so what you see matches what you hear. With the Native engine in Exclusive mode, it’s usually under 10 ms. Bluetooth headphones always add a much longer delay than wired ones.

Auto-Level on Load

Some MIDI files jump between very quiet and very loud passages. Turn on Auto-Level on Load in Settings → Audio and Orfeo checks each file as it opens; if the levels vary a lot, it switches on the mixer’s compressor to even them out. It’s off by default and works with the Studio and Native engines.

 Tip

Use General MIDI while you clean up a file in the editors, where instant response matters more than sound quality, then switch to Studio to practise, or to Native (beta) to play along on a MIDI keyboard.