Graphic Equalizer

How this works. Each slider drives a peaking biquad filter at the ISO octave centres (31.5, 63, 125, 250, 500, 1k, 2k, 4k, 8k, 16k Hz). The classic graphic-EQ shape is one-octave bandwidth (Q ≈ 1.4) — the WIDTH control widens or narrows every band at once, from 3-octave smooth tone shaping (wide) down to 1/3-octave surgical cuts (narrow). The bands are wired in series so adjacent bands overlap naturally. The spectrum bars above are sampled after the filter chain, so what you see is exactly what comes out of your speakers (or your headphones, if you're using them). You can drag the dots on the EQ curve directly to tweak each band, or use the sliders below — both update the same biquads. Bypass is a real bypass: it ramps all filter gains to 0 rather than rewiring the graph, so there are no clicks when you toggle.