The AFC-FIR card is used to realize the high density of FIR processing that was not previously possible. AFC3 systems with the AFC-FIR card are capable of working with FIR filter sets that contain 125 times as many taps as previous AFC systems. This increase in the size and density of the FIR filter sets available make it possible to achieve much longer increases in a room’s natural reverberation time without unnatural sounding artifacts.