Hello everyone please help to understand the circuit attached i calculated the frequency cut is 1khz but try to understand the circuit and the graph response please help me thank and regards

 

It's a rather complex series of active and passive filters.
I'm not sure what their purpose or why they have such a peaked output.
Whatever the purpose of the circuit, it seems like overkill.

 

It's the 150uF caps on the outputs of the opamps causing the peaking.