Summary: In the present contribution we compare the new multitaper filtering technique with the very popular filter diagonalization method. The substitution of a time-independent problem, like the standard Schrödinger equation, by a time-dependent one from the filter diagonalization method allows the employment of and comparison with standard signal processing filtration machinery. The use of zero-order prolate spheroidal tapers as filtering functions is here extended and exactly formulated using techniques originating from general investigations of prolate spheroidal wave functions. We investigate the modifications presented with respect to accuracy and general effectiveness. The approach may be useful in various branches of physics and engineering sciences including signal processing applications as well as possibly also in general time-dependent processes.