DSPBuilder signaltap tuning

You need to put in a Decimating Filter to Decimate the data to a lower sample rate:

IE if you codec is running at 192 Kbps, and you only need 48 Kbps, you can simply through 3 out of 4 samples away, but the 192 Kbps, may have some components that are above 24 KHz, so these would show up the output

A Decimating filter does 2 things, It basically is a low pass filter that kills anything that would violate the nyquest frequency of the new sample rate, an down samples the data to the new sampling rate.

Pete