Used with BASS_FXGetParameters and BASS_FXSetParameters to retrieve and set the parameters of an auto wah effect.

typedef struct {
    float fDryMix;
    float fWetMix;
    float fFeedback;
    float fRate;
    float fRange;
    float fFreq;
    int lChannel;


fDryMix Dry (unaffected) signal mix [-2....+2]
fWetMix Wet (affected) signal mix [-2....+2]
fFeedback Output signal to feed back into input [-1....+1]
fRate Rate of sweep in cycles per second [0<...<10]
fRange Sweep range in octaves [0<...<10]
fFreq Base frequency of sweep range [0<..1000]
lChannel The affected channels using BASS_BFX_CHANxxx flags   

The effect implements the auto-wah by using 4-stage phaser effect which moves a peak in the frequency response up and down the frequency spectrum by amplitude of input signal.

The fDryMix is the volume of input signal & the fWetMix is the volume of delayed signal. The fFeedback sets feedback of auto wah (phaser). The fRate and fRange control how fast and far the frequency notches move. The fRate is the rate of sweep in cycles per second, fRange is the width of sweep in octaves. And the the fFreq is the base frequency of sweep.


Dry Wet Feedback Rate Range Freq
Slow Auto Wah 0.500 1.500 0.5 2.0 4.3 50.0
Fast Auto Wah 0.500 1.500 0.5 5.0 5.3 50.0
Hi Fast Auto Wah 0.500 1.500 0.5 5.0 4.3 500.0

See also