Glossary of Terms
QThe 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 
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  | 
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