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 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