Vector Phaseshaping Synthesis (VPS)
Proc. of the 14th Int. Conference on Digital Audio Effects (DAFx-11), September 19-23, IRCAM, Paris, France, 2011.
1 Aalto University, School of Electrical Engineering, Espoo, Finland
2 National University of Ireland, Maynooth, Ireland
Abstract
This paper introduces the Vector Phaseshaping (VPS) synthesis
technique, which extends the classic Phase Distortion method by
providing flexible means to distort the phase of a sinusoidal oscillator.
This is achieved by describing the phase distortion function
using one or more breakpoint vectors, which are then manipulated
in two dimensions to produce waveshape modulation at control
and audio rates. The synthesis parameters and their effects are explained,
and the spectral description of the method is derived. Certain synthesis
parameter combinations result in audible aliasing,
which can be reduced with a novel aliasing suppression algorithm
described in the paper. The extension is capable of producing a
variety of interesting harmonic and inharmonic spectra, including
for instance, formant peaks, while the two-dimensional form of the
control parameters is expressive and is well suited for interactive
applications.
Software
The figures presented in the paper can be reproduced using these
python scripts
(tested with SciPy v0.7.1).
Sound Examples
The sounds are 32-bit float wavs, sampling rate is 44.1 kHz.
A) control rate modulation
Sound |
Description |
Size (MB) |
vps-chord.wav |
5 modulation clips: d, v, v and d, lissajous (sinusoidal LFO on v), lissajous (pulse LFO on v) |
2.15 |
vps-d.wav |
d modulated, constant v = 0.5 |
1.76 |
vps-v.wav |
v modulated 0..5, constant d = 0.5 |
3.23 |
vps-v-aa.wav |
v modulated 0..5 (alias suppression using two-oscillator crossfading), constant d = 0.5 |
3.07 |
vps-resonant.wav |
varying d and v manually with a 2D controller |
1.63 |
vps-resonant-aa.wav |
varying d and v manually with a 2D controller (alias suppression using two-oscillator crossfading) |
2.55 |
vps-lissajous1.wav |
Lissajous modulation #1 |
1.84 |
vps-lissajous2.wav |
Lissajous modulation #2 |
2.15 |
B) audio rate modulation
All sound examples (18.4 MB):
vps-examples.zip
Contact
Please send your comments and remarks to the first author: firstname.lastname[-at-]aalto.fi
Page last modified Sep-21-2011.