  A dual frames multiplier is an operator consisting of analysis,
multiplication and synthesis processes, where the analysis and the synthesis
are made by two dual frames in a Hilbert space, respectively. In this paper we
investigate the spectra of some dual frames multipliers giving, in particular,
conditions to be at most countable. The contribution extends the results
available in literature about the spectra of Bessel multipliers with symbol
decaying to zero and of multipliers of dual Riesz bases.
