/en/tags/secondary-path/Recent content in Secondary Path on Mi&Bee BlogHugo -- gohugo.ioen蓝宝石的傻话Mon, 11 May 2026 10:00:00 +0800/en/posts/physical-world/fxlms-anc-architecture/Mon, 11 May 2026 10:00:00 +0800/en/posts/physical-world/fxlms-anc-architecture/<p>Active Noise Control (ANC) works by generating an acoustic wave with equal amplitude and opposite phase to the incoming noise, canceling it through destructive interference at the target zone. Translating this into hardware requires two decisions: which sensors to use for noise sensing, and what control strategy to apply for anti-noise generation. These two factors define the three canonical ANC architectures: feedforward, feedback, and hybrid.</p> <h2 id="feedforward-anc">Feedforward ANC</h2> <p>A feedforward ANC system places a reference microphone upstream of the noise source to capture the disturbance early, feeds it to the DSP, and drives the speaker to produce the anti-noise. An error microphone near the ear monitors the residual noise and feeds it back to the adaptive algorithm for coefficient update.</p>