Local sensing/control or global error sensing/control in structural acoustics: A comparison of two techniques influence over sound power

Active Noise Control Using Carbon Nanotube Thermophones: Case Study for an Automotive Hvac Application

“…A second circular wave must be generated obviously, but the location of the origin for this second wave is now critically important. In order to completely cancel the whole disturbance in this case, the control must share its origin point with the disturbance [31,32]. If this is not the case, only local cancellation at locations where the two wave fronts cross is attainable ( Figure 4).…”