What it does
Demonstrates how the sample-rate can be arbitrarily down-sampled with downstream components automatically adjusting themselves to the new sample rate.
In this example, the base rate of the audio file is down-sampled from 44100 Hz by a factor of 2 to 22050 Hz using an FIR 2-band polyphase re-sampler (the Nyquist Decimating Down: 2 block). The 1-tap Delay block automatically configures itself such that the desired delay is achieved irrespective of the sample-rate.
The up-sampler (Nyquist Interpolating Up: 2 block) is required to bring the sample-rate up to that supported by the audio output device.