We presently consider an enhancement to the DUET sound
source separation system [
1]. Specifically, we
expand the system and the related delay and scale subtraction
scoring (DASSS) [
2] to allow sounds from exactly two
sources to be active at the same point in time-frequency (STFT)
space. We begin with a review of the DUET system and its sparsity
and independence assumptions. We then consider how the DUET system
and DASSS respond when faced with two active sources at the same
point in time-frequency space. For this case, we show the
important result that the DUET and DASSS data may reveal which two
sources are active. To exploit this result, we present a
Bayesian framework for determining the most likely sources given
DUET and DASS data. We then show how to use this framework on DASSS
data. We conclude with an example showing the
efficacy of using DASS data for determining and demixing two
active sources.