Digital Waveguide Modeling of Wind Instrument Bores Constructed of Truncated 

Cones



Vesa VŠlimŠki and Matti Karjalainen



Helsinki University of Technology

Acoustics Laboratory

Otakaari 5A, FIN-02150 Espoo, Finland	



and



CARTES

(Computer Arts Centre at Espoo)

Ahertajankuja 4, FIN-02100 Espoo, Finland



vpv@vipunen.hut.fi, matti_karjalainen@hut.fi





Abstract



This paper deals with waveguide simulation of acoustic tube systems that are constructed of conical 

tube sections. Digital reflection filters needed for modeling the scattering that occurs at a junction of 

conical tubes are presented. It is known that the reflection filter can be unstable in certain cases. 

However, the overall system is stable if it corresponds to a physically realizable system. 

Furthermore, a fractional delay waveguide model (FDWM), where the length of each conical tube 

section can be accurately adjusted, is introduced. The methods described in this paper are directly 

applicable to the waveguide synthesis of wind instruments.