The final target of this research is to develop 'Active Acoustic Filter' for a radiator cooling fan. It is set just in front of a radiator and reduces the fan noise. Active acoustic filter is constructed with many short ANC ducts, called 'cells', which have high open area ratio and low pressure loss. In this paper, as the first step, an ANC cell using a flat speaker was designed and manufactured trially. Based on some experiments, it is proved that the ANC cell can attenuate random noise in 300〜1700Hz by 10〜20dB.
