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XAUDIO2FX_REVERB_PARAMETERS structure

Describes parameters for use in the reverb APO.

Syntax


typedef struct XAUDIO2FX_REVERB_PARAMETERS {
  float  WetDryMix;
  UINT32 ReflectionsDelay;
  BYTE   ReverbDelay;
  BYTE   RearDelay;
  BYTE   PositionLeft;
  BYTE   PositionRight;
  BYTE   PositionMatrixLeft;
  BYTE   PositionMatrixRight;
  BYTE   EarlyDiffusion;
  BYTE   LateDiffusion;
  BYTE   LowEQGain;
  BYTE   LowEQCutoff;
  BYTE   HighEQGain;
  BYTE   HighEQCutoff;
  float  RoomFilterFreq;
  float  RoomFilterMain;
  float  RoomFilterHF;
  float  ReflectionsGain;
  float  ReverbGain;
  float  DecayTime;
  float  Density;
  float  RoomSize;
  BOOL   DisableLateField;
} XAUDIO2FX_REVERB_PARAMETERS;

Members

WetDryMix

Percentage of the output that will be reverb. Allowable values are from 0 to 100.

ReflectionsDelay

The delay time of the first reflection relative to the direct path. Permitted range is from 0 to 300 milliseconds.

Note  All parameters related to sampling rate or time are relative to a 48kHz sampling rate and must be scaled for use with other sampling rates. See remarks section below for additional information.

ReverbDelay

Delay of reverb relative to the first reflection. Permitted range is from 0 to 85 milliseconds.

Note  All parameters related to sampling rate or time are relative to a 48kHz sampling rate and must be scaled for use with other sampling rates. See remarks section below for additional information.

RearDelay

Delay for the left rear output and right rear output. Permitted range is from 0 to 5 milliseconds.

Note  All parameters related to sampling rate or time are relative to a 48kHz sampling rate and must be scaled for use with other sampling rates. See remarks section below for additional information.

PositionLeft

Position of the left input within the simulated space relative to the listener. With PositionLeft set to the minimum value, the left input is placed close to the listener. In this position, early reflections are dominant, and the reverb decay is set back in the sound field and reduced in amplitude. With PositionLeft set to the maximum value, the left input is placed at a maximum distance from the listener within the simulated room. PositionLeft does not affect the reverb decay time (liveness of the room), only the apparent position of the source relative to the listener. Permitted range is from 0 to 30 (no units).

PositionRight

Same as PositionLeft, but affecting only the right input. Permitted range is from 0 to 30 (no units).

Note  PositionRight is ignored in mono-in/mono-out mode.

PositionMatrixLeft

Gives a greater or lesser impression of distance from the source to the listener. Permitted range is from 0 to 30 (no units).

PositionMatrixRight

Gives a greater or lesser impression of distance from the source to the listener. Permitted range is from 0 to 30 (no units).

Note  PositionMatrixRight is ignored in mono-in/mono-out mode.

EarlyDiffusion

Controls the character of the individual wall reflections. Set to minimum value to simulate a hard flat surface and to maximum value to simulate a diffuse surface. Permitted range is from 0 to 15 (no units).

LateDiffusion

Controls the character of the individual wall reverberations. Set to minimum value to simulate a hard flat surface and to maximum value to simulate a diffuse surface. Permitted range is from 0 to 15 (no units).

LowEQGain

Adjusts the decay time of low frequencies relative to the decay time at 1 kHz. The values correspond to dB of gain as follows:

Value0123456789101112
Gain (dB)-8-7-6-5-4-3-2-10+1+2+3+4

 

Note  A LowEQGain value of 8 results in the decay time of low frequencies being equal to the decay time at 1 kHz.

Permitted range is from 0 to 12 (no units).

LowEQCutoff

Sets the corner frequency of the low pass filter that is controlled by the LowEQGain parameter. The values correspond to frequency in Hz as follows:

Value0123456789
Frequency (Hz)50100150200250300350400450500

 

Permitted range is from 0 to 9 (no units).

HighEQGain

Adjusts the decay time of high frequencies relative to the decay time at 1 kHz. When set to zero, high frequencies decay at the same rate as 1 kHz. When set to maximum value, high frequencies decay at a much faster rate than 1 kHz.

Value012345678
Gain (dB)-8-7-6-5-4-3-2-10

 

Permitted range is from 0 to 8 (no units).

HighEQCutoff

Sets the corner frequency of the high pass filter that is controlled by the HighEQGain parameter. The values correspond to frequency in kHz as follows:

Value01234567891011121314
Frequency (kHz)11.522.533.544.555.566.577.58

 

Permitted range is from 0 to 14 (no units).

RoomFilterFreq

Sets the corner frequency of the low pass filter for the room effect. Permitted range is from 20 to 20,000 Hz.

Note  All parameters related to sampling rate or time are relative to a 48kHz sampling rate and must be scaled for use with other sampling rates. See remarks section below for additional information.

RoomFilterMain

Sets the pass band intensity level of the low-pass filter for both the early reflections and the late field reverberation. Permitted range is from -100 to 0 dB.

RoomFilterHF

Sets the intensity of the low-pass filter for both the early reflections and the late field reverberation at the corner frequency (RoomFilterFreq). Permitted range is from -100 to 0 dB.

ReflectionsGain

Adjusts the intensity of the early reflections. Permitted range is from -100 to 20 dB.

ReverbGain

Adjusts the intensity of the reverberations. Permitted range is from -100 to 20 dB.

DecayTime

Reverberation decay time at 1 kHz. This is the time that a full scale input signal decays by 60 dB. Permitted range is from 0.1 to infinity seconds.

Density

Controls the modal density in the late field reverberation. For colorless spaces, Density should be set to the maximum value (100). As Density is decreased, the sound becomes hollow (comb filtered). This is an effect that can be useful if you are trying to model a silo. Permitted range as a percentage is from 0 to 100.

RoomSize

The apparent size of the acoustic space. Permitted range is from 1 to 100 feet.

DisableLateField

If set to TRUE, disables late field reflection calculations. Disabling late field reflection calculations results in a significant CPU time savings.

Note  The DirectX SDK versions of XAUDIO2 don't support this member.

Remarks

All parameters related to sampling rate or time are relative to a 48kHz voice and must be scaled for use with other sampling rates. For example, setting ReflectionsDelay to 300ms gives a true 300ms delay when the reverb is hosted in a 48kHz voice, but becomes a 150ms delay when hosted in a 24kHz voice.

Platform Requirements

Windows 8, Windows Phone 8 (XAudio 2.8); DirectX SDK (XAudio 2.7)

Requirements

Header

Xaudio2fx.h

See also

XAudio Structures
XAudio2CreateReverb
IXAudio2Voice::SetEffectParameters
How to: Create an Effect Chain
XAPO Overview

 

 

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