AudioFilter
AudioFilter adjusts the frequency content of audio streams. It provides one Input pin and one Output pin which can be connected to/from by Wires. AudioFilter uses its FilterType, Gain, and Q properties to determine what to do around a particular cutoff Frequency.
Code Samples
-- This assumes the workspace contains a Part with an AudioEmitter and an AudioPlayer, and the camera has an AudioListener
local RunService = game:GetService("RunService")
local part: BasePart = workspace.Part
local camera: Camera = workspace.CurrentCamera
local audioPlayer: AudioPlayer = part.AudioPlayer
local audioEmitter: AudioEmitter = part.AudioEmitter
local audioListener: AudioListener = camera.AudioListener
local raycastParams = RaycastParams.new()
raycastParams.FilterDescendantsInstances = {audioEmitter.Parent}
raycastParams.FilterType = Enum.RaycastFilterType.Exclude
-- Create a new AudioFilter
local filter: AudioFilter = Instance.new("AudioFilter")
filter.FilterType = Enum.AudioFilterType.Lowpass12dB
filter.Frequency = 22000
filter.Q = math.sqrt(2) / 2 -- This Q value produces a flat lowpass for the 12dB slope type
filter.Parent = part
-- Put the AudioFilter between the player and the emitter
local function wireTo(source: Instance, target: Instance): Wire
local wire = Instance.new("Wire")
wire.SourceInstance = source
wire.TargetInstance = target
wire.Parent = target
end
wireTo(audioPlayer, filter)
wireTo(filter, audioEmitter)
-- Update the filter based on the positions of the emitter and listener
RunService.Heartbeat:Connect(function()
local emitterPos: Vector3 = part.Position
local listenerPos: Vector3 = camera.CFrame.Position
local raycastResult = workspace:Raycast(emitterPos, (listenerPos - emitterPos), raycastParams)
filter.Frequency = if raycastResult then 500 else 22000
end)
Summary
Properties
Whether audio streams are passed-through unaffected by this effect.
The curve type of the band represented by the filter.
The central frequency that the filter acts around.
For peaking and shelving filters, controls volume increase or reduction.
For peaking, lowpass, highpass, bandpass, and notch filters, controls the selectiveness or resonance.
Methods
Returns an array of Wires that are connected to the specified pin.
Returns the magnitude response of the filter at the given frequency.
Properties
Editor
FilterType
The type of frequency response curve that will be used to filter the audio signal. Each type of curve affects the frequency content of the audio in different ways.
Frequency
The central frequency in hertz of the curve represented by the filter. Generally, adjusting this value up or down corresponds to a horizontal shift in the overall frequency curve. Ranges from 20 to 22000.
Gain
The gain value in decibels used to determine the volume level of the curve represented by the filter. Only applies when the FilterType is Peak, LowShelf, or HighShelf. Ranges from -30 to 30.
The quality value used to determine the slope or resonance of the curve represented by the filter. Only applies when the FilterType is Peak, Lowpass[x]dB, Highpass[x]dB, Bandpass, or Notch. Ranges from 0.1 to 10.
For FilterType values of Lowpass12dB and Highpass12dB, a Q value of sqrt(2) / 2, or 0.707, corresponds to a flat filter at a 12dB/octave slope.
Methods
GetConnectedWires
Returns an array of Wires that are connected to the specified pin. AudioFilter has one "Input" pin and one "Output" pin.
Parameters
Returns
GetGainAt
Returns the gain value, in decibels, of the frequency response curve represented by the filter at the given frequency, in hertz. This can be used to sample the exact shape of the filter in key places or as a whole.
Parameters
The frequency, in hertz, to sample.
Returns
The gain value, in decibels, at the given frequency.