A sound FX or an instrument had a 5-Band-EQ with fixed bands and a Filter with one band. The Parametric EQ holds up to ten bands of any type, and a double-click on the node opens an editor that draws the curve they make together. - The bands are a list on the node (`bands`): type, frequency, gain, Q and slope. A hand-edited project is held to the editor's ranges and to ten bands. - Each band compiles to the existing `pass` stage, so the audio core is unchanged. A peak or a shelf at 0 dB is left out. - The curve is worked out in `parametricEq.ts` with the biquad formulas of the Web Audio spec, so the editor draws what is heard. - The editor is a window that floats over the editor without a backdrop, so the tab's Play stays usable. A double-click adds a peak, a drag moves a band, the wheel turns its Q, a right-click removes it. Fields below the curve set the picked band. It opens in the middle of the screen and moves by its title bar. - A drag or a scrub writes the node as a preview and makes one undo step on release. The panels hear of the preview once a frame, and the window lays itself out only when one of its texts changes. - The area under the curve is filled as one shape for each side of 0 dB. As a single shape it crossed itself and came apart. - The curve works out each band's coefficients once and adds the sum up from the bands. A drag took 295 ms of script time in a profile before and 64 ms after. Decided on my own: - Bands are added by a double-click, so a single click can let go of the picked band without adding one. - The cuts are labelled "Low cut" and "High cut" as in an EQ, not "High-pass" and "Low-pass" as on the Filter. - The bands have no input, so no parameter or Envelope moves them. Tests: - Unit parametric-eq (new) and soundfx: 69 green. Counter-probe with no stages emitted: the compile test red. Counter-probe with one fill shape: the fill test red. - e2e 34 (melektaus-atx): ALL PASSED, 96 checks (3 new). - Counter-probe e2e: no stages emitted, the playing check red. - Gate (melektaus-atx): CHECK EXIT 0, 274 files, 4230 tests. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>