Introduction - If you have any usage issues, please Google them yourself
Double belt pass filter using firpmord and firpm function design, for its indicators, through the first area index: f = 4 kHz, f = 5 kHz, f = 3.6 kHz, f = 5.4 kHz
The second bandpass indicators: f = 6 kHz, f = 7 kHz, f = 5.6 kHz, f = 7.4 kHz
Pass band attenuation A < 3 db, stop-band attenuation A > 40 db, f = 20 KHZ sampling frequency.