Active control of sound and vibration is one of the most fascinating subjects in the field of acoustics. The main idea is to cancel sound and/ or vibrations by sound and/or vibrations. The first patents were already given in the thirties of this century. However, increasing computational power has opened a variety of possibilities for the application of active control. The example shows the control of a sound field in a duct with one or two controlling sources. 

Keywords:

Active control

standing waves
absorber
reflector
