I want to see the frequency response of 1024 order bandpass filter in MATLAB.
The sampling frequency is 16kHz and the pass band frequency is [376Hz 480Hz]. I have implemented the bandpass filter using inbuilt function fir1
as b1 = fir1(1024,[376/8000 480/8000],'bandpass')
.
To plot the frequency response of the filter, I have used the inbuilt function freqz(b1,1,10000,16000)
.
My doubt is -3dB frequency obtained from the MATLAB plot should be at the pass band cut off frequency i.e at 376Hz and 480Hz right?
Now I tried to plot the magnitude response using fdatool in MATLAB, by providing the following details: FIR equiripple filter was selected order=1024 Fs=16000 Fstop1=256 Fpass1=376 Fpass2=480 Fstop2=600 Wstop1=1 Wpass=1 Wstop2=1 and the plot obtained was as below:
There is difference in the frequency response
window
method and you'll get your -6dB back if you feel like it ;) $\endgroup$