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Q The energy losses of relative damping (ratio of stored to dissipated
energy or ratio of reactive to resistive energy).
Fs Free air resonance of driver in Hz.
Qms Mechanical Q.
Vas Volume of air equivalent to driver from the rest position.
Cms Mechanical compliance of a loud speaker piston.
Mms Moving mass of total loud speaker piston assembly.
Xmax The maximum linear excursion of a loud speaker.
Sd Surface area of the cone.
Dia The piston diameter of a loud speaker.
Qes Electrical Q of a system.
Re DC resistance.
Le VC inductance.
Pe Maximum input power.
Qts Total Q of the system.
Sens Sensitivity. An efficiency measurement in dB’s.
Vc Volume of a closed or sealed enclosure
Vb Volume of a vented enclosure.
Fc The resonant frequency of a closed or sealed system
Fb The resonant frequency of a vented system
F3 The half-power (-3dB) frequency of a loud speaker enclosure
Qtc The Q of a loud speaker at Fc in a closed box, considering both
it’s electrical and mechanical resistance.
QL The Q of a vented box, resulting from all box losses.
DV Diameter of vent.
LV Length of vent.
H Height.
W Width.
D Depth
Glossary of Terms