Time-variant gray-box modeling of a phaser pedal

Roope Kiiski, Fabian Esqueda Flores, Vesa Välimäki

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

5 Citations (Scopus)


A method to measure the response of a linear time-variant (LTV) audio system is presented. The proposed method uses a series of short chirps generated as the impulse response of several cascaded allpass filters. This test signal can measure the characteristics of an LTV system as a function of time. Results obtained from testing of this method on a guitar phaser pedal are presented. A proof of concept gray-box model of the measured system is produced based on partial knowledge about the internal structure of the pedal and on the spectral analysis of the measured responses. The temporal behavior of the digital model is shown to be very similar to that of the measured device. This demonstrates that it is possible to measure LTV analog audio systems and produce approximate virtual analog models based on these results.
Original languageEnglish
Title of host publicationProceedings of the 19th International Conference on Digital Audio Effects
PublisherBrno University of Technology
Number of pages8
Publication statusPublished - 2016
MoE publication typeA4 Article in a conference publication
EventInternational Conference on Digital Audio Effects - Brno, Czech Republic
Duration: 5 Sep 20169 Sep 2016
Conference number: 19

Publication series

NameProceedings of the International Conference on Digital Audio Effects
ISSN (Print)2413-6700
ISSN (Electronic)2413-6689


ConferenceInternational Conference on Digital Audio Effects
Abbreviated titleDAFx
CountryCzech Republic


  • Acoustic measurements
  • Audio signal processing
  • Music technology


Dive into the research topics of 'Time-variant gray-box modeling of a phaser pedal'. Together they form a unique fingerprint.

Cite this