AudioEqualizer

local function wireUp(source: Instance, target: Instance) : Wire
    local wire = Instance.new("Wire")
    wire.Parent = target
    wire.SourceInstance = source
    wire.TargetInstance = target
    return wire
end

local function getCFrameFrom(inst: Instance) : CFrame?
    local parent = inst.Parent
    if not parent then
        return nil
    elseif parent:IsA("Model") then
        return parent.WorldPivot
    elseif parent:IsA("BasePart") then
        return parent.CFrame
    elseif parent:IsA("Attachment") then
        return parent.WorldCFrame
    elseif parent:IsA("Camera") then
        return parent.CFrame
    else
        return nil
    end
end

local function rescale(value: number, oldRange: NumberRange, newRange: NumberRange) : number
    local clamped = math.clamp(value, oldRange.Min, oldRange.Max)
    local normalized = clamped - oldRange.Min / (oldRange.Max - oldRange.Min)
    return normalized * (newRange.Max - newRange.Min) + newRange.Min
end

local assetPlayer = Instance.new("AudioPlayer")
assetPlayer.AssetId = "rbxassetid://142376088"
assetPlayer.Parent = workspace

local equalizer = Instance.new("AudioEqualizer")
equalizer.MidRange = NumberRange.new(400, 3000)
equalizer.Parent = workspace

local emitterPart = Instance.new("Part")
emitterPart.Anchored = true
emitterPart.Position = Vector3.new(0, 5, 0)
emitterPart.Parent = workspace

local emitter = Instance.new("AudioEmitter")
emitter.Parent = emitterPart

local listener = Instance.new("AudioListener")
listener.Parent = workspace.CurrentCamera

local output = Instance.new("AudioDeviceOutput")
output.Parent = workspace

wireUp(assetPlayer, equalizer)
wireUp(equalizer, emitter)
wireUp(listener, output)

assetPlayer.Looping = true
assetPlayer:Play()

while true do
    local emitterFrame = getCFrameFrom(emitter)
    local listenerFrame = getCFrameFrom(listener)
    if emitterFrame and listenerFrame then
        local towardEmitter = emitterFrame.Position - listenerFrame.Position
        local look = towardEmitter.Unit:Dot(listenerFrame.LookVector) -- ranges from [-1, 1]
        look = rescale(look, NumberRange.new(-1, 1), NumberRange.new(-20, 0))

        local distance = math.max(towardEmitter.Magnitude, 1)
        local rolloff = 1 / distance -- ranges from [0, 1]
        rolloff = rescale(rolloff, NumberRange.new(0, 1), NumberRange.new(-10, 10))

        equalizer.HighGain = look + rolloff
        equalizer.LowGain = rolloff
    end
    task.wait()
end