It is almost ten years since I last heard a pair of DCM loudspeakers, the Time Windows made famous by writer Peter Aczel in the first incarnation of his magazine The Audio Critic. The "Time" nomenclature traditionally used by DCM in their models refers to the fact that for any hi-fi component, its performance in the frequency domain is related to, and implicit in, that in the time domain, the two being connected by the mathematics of the Fourier Transform. To put it in simplistic language, a speaker's impulse response can be translated directly into its frequency response: all the information needed to show how its response varies with frequency is contained in the shape of the impulse it produces.