The Audio Low Pass Filter passes low frequencies of an AudioSource or all sound reaching an AudioListener while removing frequencies higher than the Cutoff Frequency.

The Lowpass Resonance Q (short for Lowpass Resonance Quality Factor) determines how much the filter’s self-resonance is dampened. Higher lowpass resonance quality indicates a lower rate of energy loss, i.e., the oscillations die out more slowly.

The Audio Low Pass Filter has a Rolloff curve associated with it, making it possible to set Cutoff Frequency over distance between the AudioSource and the AudioListener.

Sounds propagates very differently given the environment. For example, to compliment a visual fog effect add a subtle low-pass to the Audio Listener. The high frequencies of a sound being emitted from behind a door will be filtered out by the door and so won’t reach the listener. To simulate this, simply change the Cutoff Frequency when opening the door.

Inspector Elements

Property: Function:
Cutoff Frequency Lowpass cutoff frequency in Hertz (range 10.0 to 22000.0, default = 5000.0).
Lowpass Resonance Q Lowpass resonance quality value (range 1.0 to 10.0, default = 1.0).