In one embodiment, a sound image is generated by applying first and second
copies of a first input audio signal to first and second audio channels,
respectively, to generate first and second output audio signals for the
sound image. Each output audio signal is generated by (1) applying the
corresponding copy of the first input audio signal to a corresponding
source placement unit (SPU) to generate M delayed, attenuated, and
weighted audio signals, A>1; (2) applying each delayed, attenuated,
and weighted audio signal to a corresponding eigen filter to generate one
of M eigen-filtered audio signals; and (3) summing the M eigen-filtered
audio signals to generate the corresponding output signal. In an
alternative embodiment, M copies of a first input audio signal are
eigen-filtered prior to applying first and second copies of the resulting
eigen-filtered signals to first and second audio channels, respectively.