XAudio2CutoffFrequencyToOnePoleCoefficient function (xaudio2.h)

Inline function that converts from filter cutoff frequencies expressed in hertz to the filter coefficients used with the Frequency member of the XAUDIO2_FILTER_PARAMETERS structure.

This function applies to LowPassOnePoleFilter and HighPassOnePole filter types only, use XAudio2CutoffFrequencyToRadians for state-variable filter types.


float XAudio2CutoffFrequencyToOnePoleCoefficient(
  float  CutoffFrequency,
  UINT32 SampleRate



The cutoff frequency in hertz. Frequencies greater than SampleRate are clamped to XAUDIO2_MAX_FILTER_FREQUENCY.


The sample rate of the audio data affected by the XAUDIO2_FILTER_PARAMETERS structure.

Return value

Returns a filter coefficient for use in the XAUDIO2_FILTER_PARAMETERS structure.


You must explicitly define XAUDIO2_HELPER_FUNCTIONS in your build for this function to become available.

The DirectX SDK versions of XAUDIO2 do not support one-pole filters, so this function is not present in those releases.

Platform Requirements

Windows 10 (XAudio2.9); Windows 8, Windows Phone 8 (XAudio 2.8); DirectX SDK (XAudio 2.7)


Target Platform Windows
Header xaudio2.h

See also