PianoRes

PianoRes is an audio plugin that adds damper resonance to sampled pianos. It is designed to enhance the realism of sampled pianos by simulating the sympathetic vibrations that occur when the sustain (damper) pedal is pressed. This plugin can be used to increase realism in digital audio workstations (DAWs) or live hosts.

Built using the JUCE framework, PianoRes is compatible with various plugin formats, including LV2, VST, VST3, and AU, on various platforms.

It is currently available for Windows 64 bit (VST3) and Zynthian (Debian Bookworm on ARM, as an LV2 plugin.)

INSTALLATION

Get the plugin, example IR files, and README by clicking the Release link at the right of the github Code page. These are in a zip file. Follow the instructions in the README file.

USAGE

Note: due to Issue #4, use 48KHz sample rate, unless using your own IR file.

Plug PianoRes to process the audio output your piano sample player (sfizz, Sforzando, etc.) Unfortunately, neither sfizz nor Sforzando passes MIDI through, so you will need to do some MIDI or audio routing on your host. There's a trick to get Sforzando to pass MIDI, see below.

One option is to use two chains or tracks. On one track, plugin the player. On the other track, plugin PianoRes. Set both to receive MIDI from the same source, and patch the audio output of the player to the input of PianoRes.

Another option is to use one chain or track. Plugin the player, then plugin PianoRes after it. Using host routing, patch the MIDI input into PianoRes.

(I will be submitting a feature request to sfizz to add MIDI passthrough, which would make this much easier.)

PianoRes will work best with sampled pianos that do not already have damper resonance samples. Most of these have controls to adjust the amount of damper resonance, which you can set to zero. If your piano does have damper resonance samples and you can't easily disable them, you can still use PianoRes. [Note: editing the sfz file you can remove the resonance sample groups.]

Windows: Getting Plogue Sforzando to pass MIDI

This works only with the VST (not VST3) version of Sforzando. It might also work for LV2, but I haven't tried it.

Copy Resources/gui-settings.xml from this repo into the Sforzando GUI directory (usually, "C:\Program Files\Plogue\Sforzando\GUI".) In Sforzando GUI, choose the SETTINGS tab, and set MIDI to "Process."

Then you can simply plug PianoRes following Sforzando, and ignore the alternatives below.

Windows: Usage in Reaper, without Sforzando trick above

1. Add a track and plug in your sample player configured with your sampleset (e.g., Sforzando with Accurate Salamander Grand 6.2beta2.)
2. Add another track and plug in PianoRes. Load the impulse file. (Any piano resonance impulse file will do, but ideally one created with your piano sampleset.)
3. Set PianoRes dry control to 0%
4. Click the piano track's "ROUTE" button and click "Add new send", and choose the PianoRes Track
5. Control the amount of resonance using the PianoRes track's volume slider
6. To hear the effect only, click the piano track's ROUTE button and uncheck "Master Send"

Zynthian

PianoRes has been tested on RPi5 only. Good luck on RPi4.

Zynthian Audio buffering

Set audio buffer size to 256 samples, with 3 buffers. Both 44100 Hz and 48000 Hz have been tested and work. YMMV depending on your audio interface. If you get constant overruns/crackling, increase buffering.

Zynthian Chain setup

Load the PianoRes plugin as an Audio+MIDI chain. Load the piano (Ideally, Salamander Grand, but any piano should be OK) on another chain, and set that chain's audio output to the PianoRes chain. Disable the chain's output going to the mixer.

Zynthian Limitations

On other platforms, it's possible to load the IR file, to use one based on your sampled piano. Zynthian doesn't provide access to the file chooser, so it's not possible the normal way. Copy the desired IR file to /zynthian/zynthian-my-data/files/IRs/PianoResIR.flac All instances of PianoRes will use this IR file.

CONTROLS

The plugin has a file chooser to select the impulse response (IR) file, which is made from summing all the notes of a piano, ideally at low velocity. An impulse file for AccurateSalamanderGrand 6.2beta2 is included by default. The plugin also has gain controls for the dry signal (the original piano sound) and the wet signal (the damper resonance effect). The IR file should be a stereo audio file (e.g., WAV, AIF, OGG, or FLAC.)

The longer the IR file, the more realistic the damper resonance will sound, but it will also use more CPU resources. A good starting point is to use an IR file that is around 5-10 seconds long.

Several IR files are included with the plugin, and you can create your own by recording all notes on a piano and summing them together in a DAW, and normalizint it.

The plugin has a release time control, which adjusts how quickly the damper resonance fades out as the sustain pedal is released.

[NYI] Half-pedaling

CREATING YOUR OWN IR FILE

While the supplied IR file should sound reasonable for most grand pianos, you can create a custom IR file for your favorite sampled piano in a DAW.

Simply sample all the notes from A0 (lowest piano note) through the highest undamped note on your sampled piano and sum them all. To make it a bit easier, you can make a number of MIDI tracks that plays a set of notes, and render the audio. Adjust the volume so that the result is nearly normalized (that is, above say -3dBFS but not clipping.)

Any file format supported by JUCE is allowed (WAV, AIFF, FLAC, Ogg Vorbis, MP3, and WMA.) Any sample rate and bit depth is fine, but I suggest 16 bits at 48 KHz. Higher bit depths won't make audible differences, and 48 KHz is a commonly used sample rate.

NOTE: See Issue #4 -- IR is not resampled to current audio rate. Hopefull fixed soon.

BUILDING

I haven't tested this, but this should work on Windows. Small changes would be needed for Linux/Mac.

1. Requirements:
   1. JUCE (install at C:\JUCE on Windows, for easiest)
   2. Visual Studio 2026 (Community edition fine. I haven't tried VSCode.)
   3. this repo
2. Run JUCE "ProJucer" and load the "PianoRes.jucer" project
3. Click the VS button to the right of "Selected exporter: Visual Studio 2026". That opens VS with the project
4. Build->Build Solution
5. Hunt down the plugin you want (currently LV2 or VST3) and install it in your system. On a Mac you might be able to build AU, though you might need to change Jucer options.

License

The source code for PianoRes is licensed under the GIT "Unlicense", which means it is free to use, modify, and distribute without any restrictions. You can find the full text of the license in the LICENSE file included with the source code.

Attibution is not required, but would be appreciated.

Credits

Big thanks to https://github.com/etosphere, whose Coneko plugin helped me quickly understand how to use a convolution engine in JUCE.

Thanks also to the developers of JUCE (https://juce.com/), which is an amazing framework for building audio plugins.