Für "tap" habe ich im Zusammenhang mit FIR-Filtern die folgende Erläuterung gefunden: Tap - A FIR "tap" is simply a coefficient/delay pair. The number of FIR taps, (often designated as "N") is an indication of 1) the amount of memory required to implement the filter, 2) the number of calculations required, and 3) the amount of "filtering" the filter can do; in effect, more taps means more stopband attenuation, less ripple, narrower filters, etc.)
Quelle:
http://www.dspguru.com/info/faqs/fir/basics.htm
The translation workplace 
