Asus Xonar HDAV 1.3 - Manual (Page 51)

45 ASUS Xonar HDAV .3
4 LFE Crossover
Frequency
Adjusts the cut-off frequency (50~250Hz) for LFE (low-
frequency effects) signals. Xonar HDAV .3 will filter out
the bass signals below the crossover frequency from small
speaker channels and forward them to the subwoofer. The
higher the crossover frequency, the more bass signals will be
subtracted.