Wave field synthesis by synthesizing spatial transfer function over listening region

摘要

Broadly speaking, the technology relates to using wave field synthesis theory to simulate one or more idealized virtual point sources in a multi-speaker system. The speaker transfer function of each speaker is modeled, and the values and directional gradient of the combined speaker transfer function at test points in a convexly-bounded listening region are compared to the desired values and directional gradient for the idealized transfer function of the idealized virtual point source(s) at the test points to determine filter coefficient sets for each filter. The determined filter coefficients are those which minimize the total difference between the values and directional gradient of the combined speaker transfer function and the values and directional gradient of the idealized transfer function of the idealized virtual point source across all the test points for a plurality of frequency bins.

主权项

1. A multi-speaker sound system to simulate at least one idealized virtual point source, the system comprising:
at least one source signal input adapted to receive a respective source signal, there being one source signal input associated with each idealized virtual point source; a plurality of speakers;
each of the speakers being coupled to each source signal input by a respective parallel circuit to direct each respective source signal toward each speaker; a plurality of filters;
each filter being associated with a single speaker and a single source signal input;each filter being interposed between its respective speaker and its respective source signal input to filter the respective source signal;each filter having a respective filter coefficient set;each speaker having a speaker transfer function for each source signal input, each speaker transfer function for a particular speaker and a particular source signal input representing that speaker's beam pattern as a function of the respective filter coefficient set of the filter associated with that particular speaker and that particular source signal input; the multi-speaker sound system having a combined speaker transfer function for each source signal input, each combined speaker transfer function for a particular source signal input being a summation in space of the speaker transfer functions of the speakers for that source signal input and representing superpositioned speaker transfer functions of the speakers at notional test points within a notional convexly-bounded listening region; wherein for each combined speaker transfer function, the filter coefficients have respective values that globally minimize in frequency domain, across at least a subset of all frequency bins below a sampling frequency limit, across a frequency-sufficient set of the notional test points having known test point positions relative to notional source positions of the speakers, a total difference between that particular combined speaker transfer function and an idealized transfer function of that particular idealized virtual point source at a specified notional position of that idealized virtual point source relative to the notional source positions of the speakers.