This Filter is very loosely based on calculation for a 25kHz Lowpass filter in series with a 10Hz Highpass filter, both with a gain of 1, (aka no gain).
The upper filter is the Lowpass (starts to filter out and get rid of any part of the signal higher than 20-25kHz [everything outside of human hearing range]), the lower filter is the Highpass and starts to filter out anything below 10Hz (outside of human hearing range).
I added the 'lamp & ground' to represent the output, and the switch is there to help clearly route the schematic wire connections.
Note: a Lowpass filter has 2 resistors before the noninverting op amp input (positive signal input). It also has 2 capacitors that complete the filter. The Highpass filter has the same 4 components in the same 4 locations. The only differences are the resistor/capacitor locations are swapped, and the component values are different.
