The Combfilter Effect

In addition to sound that comes directly from the source, a microphone captures sound that is reflected by surrounded surfaces as well. Direct sound and reflected sound are interferring. As the reflected sound had a longer travel, it is not in phase with the direct sound. This leads to cancellations of several frequencies/frequency ranges and therefore a noticeable coloration of the sound: the comb filter effect. To reduce this effect it is advisable to either keep the travel of the reflected sound as close to the travel of the direct sound or let it attenuate as much as possible. Attenuation can be achieved by a very long travel, by absorbing, by choosing a microphone pattern that attenuates sound that arrives at the angle of the reflected sound.

Air temperature	°C
Ground angle	°
Height of sound source	m
Absorption of the ground

Setup

Resulting Frequency response

Audio simulation

Currently this audio simulation does not consider absorption and the frequency dependence of polar patterns. This is especially an issue for omnis.
The volume is normalized, meaning, that attenuation by greater distances and direct sound arriving at non-centre angles are balanced.

Drag your own audio file or the predefined sounds onto the player.