See here for the last release: version 2.0.0, built on 2020/06/14
This page is about Curvessor 1.1.5, built on 2020/06/08
Curvessor is a free and open source VST/VST3 audio plug-in that implements a dynamic range processor in which
the response curve of each channel is an automatable spline.
Curvessor can be used as a classic compressor/expander, enjoying the freedom and precision that comes with
But more specifically, as it allows the authoring of response curves that are not increasing
can be used for creative dynamic processing range in sound design.
is a brief video with an example of Curvessor and Overdraw
You can jump to the download section
, or browse
the source code
- The response curves are smoothly automatable splines.
- Optional Mid/Side Stereo processing.
- Forward, Feedback and Sidechain topologies.
- All the parameters, including the knots of the spline, can have different values on the Left
channel and on the Right channel
- or on the Mid channel and on the Side channel, when in Mid/Side Stero Mode.
- Up to 32x Oversampling with either Minimum Phase or Linear Phase Antialiasing.
- VU meter showing the difference between the input level and the output level.
- Customizable smoothing time, used to avoid zips when automating the knots of the splines, the stereo
link percentage, the wet amount, or the input and output gains.
The splines can be edited either by dragging the knots with the mouse, or by entering numeric
values for the selected knot.
To enable or disable a knot, double click on it.
When the knots of two different channel are overlapping, the mouse will interact with the control
point of the Left/Mid channel.
To interact with the knot of the Right/Side channel, use the right button of your mouse, or press the
key while clicking.
To zoom in or out, use the mouse scroll wheel.
Curvessor is developed and tested on Windows (VST and VST3) and Linux (VST).
If you are willing to build Curvessor from the source code, you may be able to build an AudioUnit/VST/VST3
binary for macOS.
If you encounter any issue, please contact me either here
Curvessor includes code from these third party libraries:
- The JUCE cross platform C++
- gammaenv: DSP S-curve envelope
signal generator, by Aleksey Vaneev.
- r8brain: an high-quality pro
audio sample rate converter / resampler C++ library by Aleksey Vaneev.
- HIIR: an oversampling and Hilbert
transform library by Laurent de
- vectorclass: a library for
using SIMD instructions to improve performance on modern microprocessors by Agner Fog.
- PFFFT: a pretty fast FFT, by
VST is a trademark of Steinberg Media Technologies GmbH, registered in Europe and other countries.