I have a low pass filter with 3db cut off frequency of 200Hz and a high pass passive filter with 3db cut off frequency of 2kHz.
I need to design a cascaded band pass filter which will isolate signals for each range. The low-frequency components (20 to 150 Hz) will control Blue LED lights, the mid-frequency components (200 Hz to 2 kHz) will control Green LED lights, and the high-frequency components (2.5 kHz to 20 kHz) will control Red LED lights.
My transfer function for cascaded band pass filter is as below $$ H(j\omega)= \frac{sR_2C_2} {1+sR_2C_2+sR_1C_1+s^2R_1R_2C_1C_2} $$ where \$s=j\omega\$ . In order to isolate the signals, my design will have to be low pass-band pass-high pass filter. Is it correct? I would like to know how to determine lower and upper cut off frequency. Is it 200Hz and 2kHz?