DSFXParamEq Structure

The DSFXParamEq structure contains parameters for a parametric equalizer effect.


typedef struct DSFXParamEq {
    FLOAT fCenter;
    FLOAT fBandwidth;
    FLOAT fGain;
} DSFXParamEq;


  • fCenter
    Center frequency, in hertz, in the range from DSFXPARAMEQ_CENTER_MIN to DSFXPARAMEQ_CENTER_MAX. The default value is 8000.
  • fBandwidth
    Bandwidth, in semitones, in the range from DSFXPARAMEQ_BANDWIDTH_MIN to DSFXPARAMEQ_BANDWIDTH_MAX. The default value is 12.
  • fGain
    Gain, in the range from DSFXPARAMEQ_GAIN_MIN to DSFXPARAMEQ_GAIN_MAX. The default value is 0.


The value in fCenter cannot exceed one-third of the sampling frequency of the buffer. If an attempt is made to set a value greater than this, but within the range of accepted values, the parameter is set to the nearest supported value and S_FALSE is returned by IDirectSoundFXParamEq8::SetAllParameters.


Header: Declared in DSound.h.

See Also

Parametric Equalizer