Optional
The left to left channel mix factor (0.0 ≤ x ≤ 1.0).
The left to right channel mix factor (0.0 ≤ x ≤ 1.0).
The right to left channel mix factor (0.0 ≤ x ≤ 1.0).
The right to right channel mix factor (0.0 ≤ x ≤ 1.0).
The left to left channel mix factor (0.0 ≤ x ≤ 1.0).