Excursion
The distance a driver's diaphragm is capable of moving from the at-rest position. Maximum linear excursion (Xmax) refers to how far a driver cone can move while the still under control of the motor. Mechanical excursion is how far the cone can physically move including portions where the voice coil is out of the magnetic gap. Typically, excursion figures represent the amount of movement in one direction from the at-rest position. However, movement in both directions is sometimes given with a peak-to-peak rating.