Discrete Time Emulation of the Leslie Speaker

TitleDiscrete Time Emulation of the Leslie Speaker
Publication TypeConference Paper
Year of Publication2009
AuthorsHerrera, J., C. Hanson, and J. S. Abel
Conference Name127th Audio Engineering Society Convention
Date Published10/2009
Conference LocationNew York, NY, USA
KeywordsLeslie FIR

A discrete-time emulation of the Leslie speaker acoustics is described. The midrange horn and subwoofer baffle are individually modeled, with their rotational dynamics separately tracked, and used to drive time- varying FIR filters applied to the input. The rotational speeds of the horn and baffle are modeled using FIR filters having different shapes for acceleration and deceleration. Several time-varying FIR filter methods were explored, all based on impulse responses tabulated over a dense set of horn and baffle angles. In one method, the input sample scales an interpolated impulse response at the current horn or baffle angle, which is added to the output. An example model of a Leslie 44W is presented.