Filters & augmentation

Filters

Each queue has a FilterManager at queue.filters. Every method sends an update to Lavalink immediately and returns the resulting state — no separate apply step.

Common presets

// Nightcore — faster, higher pitch
await queue.filters.set("timescale", { speed: 1.3, pitch: 1.3 });

// Vaporwave — slower, lower pitch
await queue.filters.set("timescale", { speed: 0.8, pitch: 0.8 });

// 8D audio — rotating stereo field
await queue.filters.set("rotation", { rotationHz: 0.2 });

// Bass boost
await queue.filters.set("equalizer", [
  { band: 0, gain: 0.3 },
  { band: 1, gain: 0.2 },
  { band: 2, gain: 0.1 },
]);

// Karaoke — attenuate vocals
await queue.filters.set("karaoke", { level: 1.0, monoLevel: 1.0, filterBand: 220, filterWidth: 100 });

// Soft tremolo
await queue.filters.set("tremolo", { frequency: 4, depth: 0.3 });

Available filters

Key	Effect
volume	Output volume multiplier (0.0–5.0, where 1.0 = 100%). Separate from queue.setVolume() which uses 0–1000
equalizer	15-band EQ. Each band: { band: 0–14, gain: -0.25–1.0 }
karaoke	Attenuates a frequency band — typically reduces vocals
timescale	Adjust speed, pitch, and rate independently (all default to 1.0, must be > 0)
tremolo	Rapidly oscillate volume (frequency > 0, depth > 0 and ≤ 1)
vibrato	Rapidly oscillate pitch (frequency > 0 and ≤ 14, depth > 0 and ≤ 1)
rotation	Rotate audio around the stereo field — the 8D effect (rotationHz)
distortion	Wave-function distortion with sin/cos/tan offset and scale controls
channelMix	Blend left and right channels (leftToLeft, leftToRight, rightToLeft, rightToRight, each 0–1)
lowPass	Suppress high frequencies (smoothing > 1.0 — values ≤ 1.0 disable the filter)
pluginFilters	Filters from Lavalink server plugins

Note

Filter availability depends on your Lavalink server. Use player.nodes.supports('filter', 'timescale', 'us-east') to check before applying.

Reading and checking

queue.filters.get("timescale"); // TimescaleFilter | null
queue.filters.has("rotation"); // boolean

Removing and composing

// Remove specific filters — returns the updated Filters object
await queue.filters.remove("timescale", "rotation");

// Clear by type — returns the updated Filters object
await queue.filters.clear(); // remove everything
await queue.filters.clear("native"); // built-in filters only
await queue.filters.clear("plugin"); // plugin filters only

// Merge — shallow-merges into the current filter state, returns updated Filters
await queue.filters.merge({ volume: 1.5 });

// Override — replaces the entire filter state, returns updated Filters
await queue.filters.override({ timescale: { speed: 1.2 } });

Use merge when you want to layer effects on top of what’s already active. Use override when you want a clean slate.

set() returns the value that was just applied:

const ts = await queue.filters.set("timescale", { speed: 1.3, pitch: 1.3 });
// ts → { speed: 1.3, pitch: 1.3 }

Plugin filters

Plugin filters live under pluginFilters in the filter object. Pass true as the third argument to set():

await queue.filters.set("myFilter", { intensity: 0.8 }, true); // isPlugin = true

Declare the type so it propagates everywhere:

declare module "discolink" {
  interface CommonPluginFilters {
    myFilter: { intensity: number };
  }
}

Full type definitions: Filters

---

TypeScript augmentation

Four interfaces can be augmented. Declare them once in a .d.ts file and the types appear everywhere — no casting, zero runtime cost.

Interface	What it types	Where it appears
QueueContext	Data you attach to a queue	queue.context, CreateQueueOptions, PlayOptions
CommonUserData	Data you attach to a track	track.userData, PlayOptions, queue.add()
CommonPluginInfo	Plugin-provided track/playlist metadata	track.pluginInfo, playlist.pluginInfo
CommonPluginFilters	Plugin-provided audio filters	queue.filters, all FilterManager methods

All augmented interfaces extend JsonObject — values must be JSON-serializable. Augmentations are compile-time only with no runtime cost.

// augment.d.ts — include this file in your tsconfig
declare module "discolink" {
  interface QueueContext {
    textChannelId: string;
    requestedBy: string;
  }

  interface CommonUserData {
    userId: string;
    username: string;
  }

  interface CommonPluginFilters {
    customEcho: { delay: number; decay: number };
  }
}

The types flow through without any extra work:

const queue = await player.queues.create({
  guildId,
  voiceId,
  context: { textChannelId: "123", requestedBy: "user1" }, // ✓ typed
});

queue.context.textChannelId; // ✓ string

queue.add(track, { userId: "abc", username: "Alice" }); // ✓ typed

await queue.filters.set("customEcho", { delay: 200, decay: 0.5 }); // ✓ typed

player.on("trackStart", (queue, track) => {
  console.log(track.userData.username); // ✓ string
  console.log(queue.context.textChannelId); // ✓ string
});