_ExponentialToLinear
_DbToGain(_ExponentialToLinear(kVolumeDbMin)) * kVolumeFactor,
_DbToGain(_ExponentialToLinear(kVolumeDbMax)) * kVolumeFactor,
fVolumeSlider->SetValue(_DbToGain(_ExponentialToLinear(0.0))
float db = _ExponentialToLinear(_GainToDb(pos));
float _ExponentialToLinear(float db);