Built-in equalizer #96

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opened 2026-10-19 20:23:10 +02:00 by SBDeveloper · 1 comment

SBDeveloper commented

2026-10-19 20:23:10 +02:00

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A built-in equalizer for everything the app plays. Design decided in a grilling session; see ADR 0023 and the Equalizer / Equalizer preset terms in GLOSSARY.md.

Why built in, not a plugin

process runs on the decoder thread, which buffers about 8 s ahead of the Output, so a slider move would be heard up to 8 s late. The filters must sit after the buffer, in the host; a plugin would only draw sliders.

Behaviour

Filters run in Player::render, after the buffer and before volume. Every Output (local, VBAN, stream listeners) and the Visualizer tap (ADR 0016) see the shaped audio. Spotify via Soloist is shaped.
Ten graphic bands plus a preamp, up to 12 dB cut or boost per band.
One global setting. Persists across restarts like the Crossfade length.
UI in Playback settings next to Crossfade: preset picker, 10 vertical sliders, preamp, reset.
Presets: Flat (default), a few built-ins, user-saved ones (save, rename, delete). Editing a band after choosing a preset makes it Custom until saved.
Flat means all gains 0: the host skips the stage. No separate enable switch.
Clipping: the host lowers gain by the largest boost; the user may raise the preamp by hand. No limiter.
No clicks: filter state carries across Track boundaries and crossfades; changed gains ramp over a few tens of ms.
Video mode (ADR 0022) is not shaped; the UI says why while a video plays (as #93 does for the Visualizer).

Out of scope

Per-Output, per-Source or per-Playlist curves; parametric bands; a limiter.

Notes for the implementer

UiNode (plugin UI) has no slider and does not need one: this is core Svelte UI, ui/src/lib/Playback.svelte already uses <input type="range"> for Crossfade.
Update the ADR status from "not yet implemented" when done.

A built-in equalizer for everything the app plays. Design decided in a grilling session; see ADR 0023 and the **Equalizer** / **Equalizer preset** terms in `GLOSSARY.md`. ## Why built in, not a plugin `process` runs on the decoder thread, which buffers about 8 s ahead of the Output, so a slider move would be heard up to 8 s late. The filters must sit after the buffer, in the host; a plugin would only draw sliders. ## Behaviour - Filters run in `Player::render`, after the buffer and before volume. Every Output (local, VBAN, stream listeners) and the Visualizer tap (ADR 0016) see the shaped audio. Spotify via Soloist is shaped. - Ten graphic bands plus a preamp, up to 12 dB cut or boost per band. - One global setting. Persists across restarts like the Crossfade length. - UI in Playback settings next to Crossfade: preset picker, 10 vertical sliders, preamp, reset. - Presets: Flat (default), a few built-ins, user-saved ones (save, rename, delete). Editing a band after choosing a preset makes it Custom until saved. - Flat means all gains 0: the host skips the stage. No separate enable switch. - Clipping: the host lowers gain by the largest boost; the user may raise the preamp by hand. No limiter. - No clicks: filter state carries across Track boundaries and crossfades; changed gains ramp over a few tens of ms. - Video mode (ADR 0022) is not shaped; the UI says why while a video plays (as #93 does for the Visualizer). ## Out of scope Per-Output, per-Source or per-Playlist curves; parametric bands; a limiter. ## Notes for the implementer - `UiNode` (plugin UI) has no slider and does not need one: this is core Svelte UI, `ui/src/lib/Playback.svelte` already uses `<input type="range">` for Crossfade. - Update the ADR status from "not yet implemented" when done.

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2026-10-19 20:23:10 +02:00

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2026-10-21 20:30:48 +02:00

SBDeveloper changed title from ~~Equalizer plugin~~ to Built-in equalizer

2026-10-21 20:30:49 +02:00

SBDeveloper commented

2026-10-21 21:03:04 +02:00

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Implemented on main (commits daa5584, e8c747a, 72776fc, e5e9183, b3d7f89; not pushed when this was written).

Built in rather than a plugin (ADR 0023): ten graphic bands and a preamp in Player::render, presets (built-in and user-saved), AutoEq import (FixedBandEQ exact, ParametricEQ kept as an Imported curve, GraphicEQ fitted to the sliders), a response graph, and the Playback settings card with two paths: Adjust yourself and Tuned for your headphones.

Scope added during the work and not in the original body: the AutoEq import, the response graph and the two-path card.

Not verified: the full core test suite (the one failure seen, low_delay a_receiver_that_is_not_set_up..., also fails at HEAD without this work) and the UI in the running app.

Implemented on main (commits daa5584, e8c747a, 72776fc, e5e9183, b3d7f89; not pushed when this was written). Built in rather than a plugin (ADR 0023): ten graphic bands and a preamp in Player::render, presets (built-in and user-saved), AutoEq import (FixedBandEQ exact, ParametricEQ kept as an Imported curve, GraphicEQ fitted to the sliders), a response graph, and the Playback settings card with two paths: Adjust yourself and Tuned for your headphones. Scope added during the work and not in the original body: the AutoEq import, the response graph and the two-path card. Not verified: the full core test suite (the one failure seen, low_delay `a_receiver_that_is_not_set_up...`, also fails at HEAD without this work) and the UI in the running app.

SBDeveloper closed this issue

2026-10-21 21:03:05 +02:00

SBDeveloper referenced this issue from a commit

2026-10-21 21:11:33 +02:00

Built-in Equalizer with AutoEq import (#96)

SBDeveloper referenced this issue from a commit

2026-10-21 21:11:33 +02:00

Equalizer import steps recommend ParametricEQ for sound quality (#96)

SBDeveloper referenced this issue from a commit

2026-10-21 21:11:33 +02:00

Equalizer sliders: turn a horizontal range upright instead of vertical writing-mode (#96)

SBDeveloper referenced this issue from a commit