Surround : Surround Panning and Mixing : Panning Modes : 3-Knob Panning

3-Knob Panning
Pro Tools provides 3-Knob mode as an additional way to input pan moves.
3-Knob mode lets you:
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Pan in straight lines, moving the Pan Location cursor using the Position rotary knobs with full movement of front, rear, and front-rear position.
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For example, when panning front-left to rear-right in 3-Knob mode, audio will be heard from just those two speakers (assuming full divergence is in effect).
By comparison, in X/Y mode a diagonal pan may result in audio being heard in some or all channels.
The difference is that 3-Knob mode pans discretely between the front and rear position of the panning trajectory, while X/Y mode panning takes place in the full 360° Panning Grid. Divergence and Center Percentage are variable in both Panning modes.
To enable 3-Knob Panning mode:
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The panner trajectory line appears across the Grid, extending from the front (X-axis) to the rear (Y-axis).
To pan in 3-Knob mode:
1 Adjust the Front and Rear Position knobs to set the trajectory line.
2 Rotate the Front/Rear Position knob to pan along the trajectory. The Pan Location cursor is constrained to the white trajectory line.
To change the 3-Knob trajectory angles, do one of the following:
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– or – 
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To change the current trajectory position (left-to-right) and retain its current angles:
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