[SciPy-user] Band pass filter design

Hi all, i would like to design a high pass filter with scipy.signal module. This is the code i'm using to: import scipy.signal as signal import scipy #first of all i design the lowpass fir filter. This is a 10 taps filter with cutoff frequency =1 (as help tell me to do) lpwindow=signal.firwin(10,1) #with the following instruction i'm creating a band pass filter from the low pass one bpwindow=signal.lp2bp(lpwindow,1,0.5,0.2) My problem is that the band-pass filter obtained with lp2bp function is 16 taps one! How is it possible?? thanks, Vincenzo