This site contains some of my applications, which I developed over the last few years.

Currently there are three standalone applications available:

  • The first application is called AudioAnalyser and is a realtime audio analyser.
  • The second one is called Multisine. It is an audio signal generator. This application is totally dated and is listed more of historical reasons.
  • My latest application is called HarmonicTune. It is a cromatic instrument tuner for nearly all kind of instruments.

Additionally to my standalone applications I developed some VST Plugins. Currently there are three simple but effective Plugins available

  • sedutecLimiter
  • sedutecStereoEnhancer
  • sedutecCompressor


The programs "Multisine", "AudioAnalyser" and "HarmonicTune" are provided as FREEWARE.

RESTRICTIONS: You may not reverse engineer, decompile, disassemble, or modify the software.

This software is provided "AS IS". The author is not liable for any damage caused directly or indirectly by the use of this software.

Copyright (C) 2005 - 2017 by Sebastian Dunst.



The program "AudioAnalyser" is a realtime frequency analyser for audio signals.

You can combine the "AudioAnalyser" with my other application "Multisine". With this combination you have a full equipped audio suite for your measurements.

I have written the application in C++ using the following libraries and tools:

Feature list of AudioAnalyser V2017.03

  • Samplingrate 1000 Hz ... 96 kHz
  • FFT length 1024 ... 32768 points
  • Stereo and Mono mode
  • Averaging mode (1-20)
  • Max hold mode
  • 5 different windows (Hanning, Hamming, Blackman, Blackman Harris, Rectangular)
  • Linear and logarithmic frequency axis
  • Vector Scope for stereo width and phase analysis
  • Real PPM Meter
  • 2 markers (Deltamarker) available
  • Variable axis settings
  • Level Correction value
  • Screenshots
  • Analyser Mode selectable between Amplitude Spectrum and Power Spectrum Density

System requirements

  • Win10, Win8, Win7, Vista
  • Soundcard



The program Multisine is an audio signal generator. All signals are calculated offline. After the calculation it is possible to store the data in a .wav file or playback data with your soundcard. The application is written in C++ and uses the VCL library and Win Api calls.

Feature list of actual revision Multisine V1.74

  • Samplingrate 1 Hz ... 48 kHz
  • Mono and Stereo Signals supported
  • File length up to 180s
  • 8 / 16 bit audioformat
  • Play and Loop Play via soundcard
  • (Multi) Sinusgenerator
  • Square generator
  • Triangle generator
  • Sawtooth generator
  • AM generator
  • FM generator
  • Sweep generator
  • Pseudo noise generator
  • Noise generator (pink, white)
  • Band noise generator
  • Offline frequency analysator (FFT, 4 different window types)
  • Signal statistics
  • Comfortable graphical display for time and frequency domain

System requirements

  • Windows Vista, Windows XP or Windows 2000
  • Soundcard

Harmonic Tune


The program HarmonicTune is an general purpose chromatic Instrument Tuner. You should be able to tune nearly every kind of instrument with it (including brass, strings, piano, guitars...). Nevertheless the algorithm for the base frequency detection is not perfect, but I hope to improve it step by step over time. The application is written in C++, uses the libraries "wxWidgets", "boost" and "portaudio" and is compiled and organized with the great free IDE "Code::Blocks" using MinGW.

Feature list of actual revision HarmonicTune 0.93

  • Universal automatic tone detection for nearly all kind of instruments
  • Theoretical tuning range from C0 ... B7
  • Samplingrate, FFT size and threshold level adjustable
  • Following fundamental frequency detections algorithms are available:
    • Power Density Spectrum
    • Cepstrum
    • Autocorrelation
  • The algorithm parameters are adjustable
  • The tuning basis is adjustable
  • Following temperaments possible:
    • Equal Temperament
    • Just Intonation
    • Meantone Temperament

System requirements

  • Windows Vista, Windows XP or Windows 2000
  • Soundcard

VST Plugins


Mainly for educational reasons regarding dsp techniques I started the development of VST plugins. My aim is to create simple but powerful plugins, doing exactly what the user would expect. Nothing more.

Currently the following plugins are available:


  • Simple Limiter Plugin
  • Its only parameter is "Threshold [dB]", where the limiter starts processing the signal.
  • Uses default gui of host application
  • Implements VST SDK Version V2.4
  • Release Date: Dec 2008


  • Stereo Enhancer Plugin
  • Its only parameter is "Width"
    • width = 1: no stereo width change
    • width < 1: decrease stereo width
    • width = 0: mono
    • width > 1: increase stereo width
  • Based on the m/s transformation matrix
  • Uses default gui of host application
  • Implements VST SDK Version V2.4
  • Release Date: Jan 2009


  • General Purpose Stereo Compressor Plugin
  • The plugin is controlled with the following 7 parameters:
    • Threshold [dB]
    • Ratio
    • Attack [ms]
    • Release [ms]
    • Stereo Link (Off/On)
    • Knee Characteristic (Hard/Soft)
    • Makeup Gain [dB]
  • Uses default gui of host application
  • Implements VST SDK Version V2.4
  • Release Date: Jan 2009