A high-oversampled, low-bit modulator typical of modern audio ADCs needs a downsampler to provide PCM audio at sampling rates ranging from 44.1kHz to 768kHz. Traditionally, a multistage downsampler requantizes at each stage, raising questions about audio transparency. We present a decimator design in which there is no requantization other than a single dithered quantization when necessary to produce a final audio output of finite precision such as 24 bits. All processing is minimum-phase and concordant with the principles introduced in [1] which optimize for a specific compact impulse response and minimal (zero) modulation noise. [2]
