Dynamic Signal Phase Distortion Using Coefficient-Modulated Allpass Filters

Timoney J, Pekonen J, Lazzarini V, Välimäki V. Dynamic Signal Phase Distortion Using Coefficient-Modulated Allpass Filters. J Audio Eng Soc. 2014;62(9):596-610. doi:10.17743/jaes.2014.0033

@article{Timoney2014_17389,
  author = {Timoney, Joseph and Pekonen, Jussi and Lazzarini, Victor and Välimäki, Vesa},
  title = {{Dynamic Signal Phase Distortion Using Coefficient-Modulated Allpass Filters}},
  journal = {Journal of the Audio Engineering Society},
  volume = {62},
  number = {9},
  pages = {596--610},
  year = {2014},
  month = sep,
  publisher = {Audio Engineering Society},
  doi = {10.17743/jaes.2014.0033},
  url = {https://doi.org/10.17743/jaes.2014.0033}
}

TY  - JOUR
TI  - Dynamic Signal Phase Distortion Using Coefficient-Modulated Allpass Filters
AU  - Timoney, Joseph
AU  - Pekonen, Jussi
AU  - Lazzarini, Victor
AU  - Välimäki, Vesa
T2  - Journal of the Audio Engineering Society
J2  - J. Audio Eng. Soc.
VL  - 62
IS  - 9
SP  - 596
EP  - 610
PY  - 2014
DA  - 2014/09/06
DO  - 10.17743/jaes.2014.0033
UR  - https://doi.org/10.17743/jaes.2014.0033
PB  - Audio Engineering Society
LA  - en
AB  - When the coefficients of a first-order allpass filter are time modulated by a periodic function, the filter behaves as a dynamic phase distortion device that produces timbral modification of its input. This filter belongs to the class of Periodic Linear Time-Varying (PLTV) systems, and thus it has different properties to the original LTI allpass filter. Such properties include a magnitude response that is not necessarily flat over all time, i.e. not allpass in the usual sense. Many interesting features of these time-varying filters can be discovered by analyzing them in the time and frequency domains. It is important to know too how the time-varying transfer function can be decomposed into recursive and nonrecursive elements, which leads to a criterion for system stability. Additionally, filter topology impacts the output wave shape; only certain configurations produce a low crest factor. These filters offer novel sonic elements for sound designers and the makers of audio effects processors.
ER  -