Frequency analysis to determine low-pass cut off frequency

1. What is the frequency of low-pass filter?
2. How to find cutoff frequency of second order low-pass filter?

What is the frequency of low-pass filter?

In audio devices, low pass filters are used to filter treble sound from 2.5 kHz to 20 kHz (high-frequency components of the audio spectrum) to subwoofers.

How to find cutoff frequency of second order low-pass filter?

A Second Order Low Pass Filter is to be design around a non-inverting op-amp with equal resistor and capacitor values in its cut-off frequency determining circuit. If the filters characteristics are given as: Q = 5, and ƒc = 159Hz, design a suitable low pass filter and draw its frequency response.