ABSTRACT

A better term might be “resampling.” In a digital playback system, it is one of several ways to enhance the performance. It involves sampling at a rate higher than the sampling Nyquist theorem (which states that a band-limited, continuous waveform may be represented by a series of discrete samples if the sampling frequency is at least twice the highest frequency contained in the waveform), meaning that each sample from the data converter at the playback end is sampled more than once, i.e., oversampled. This multiplication of samples permits digital filtering of the signal, thereby reducing the need for sharp analog filters to control aliasing (unwanted frequencies created when sampling a signal of a frequency higher than half the sampling rate). The result is a more effective way to eliminate problems at frequencies above the audible range.