Editing Thiele/Small parameters (section)

==Fundamental parameters==

These are the physical parameters of a loudspeaker driver, as measured at small signal levels, used in the equivalent electrical circuit models. Some of these values are neither easy nor convenient to measure in a finished loudspeaker driver, so when designing speakers using existing drive units (which is almost always the case), the more easily measured parameters listed under ''Small Signal Parameters'' are more practical:

*<math>S_{\rm d}</math> – Equivalent piston area of the driver diaphragm, in square metres.
*<math>M_{\rm ms}</math> – Mass of the driver diaphragm and voice-coil assembly, including acoustic load, in kilograms. The mass of the driver diaphragm and voice-coil assembly alone is known as <math>M_{\rm md}</math>.
*<math>C_{\rm ms}</math> – Compliance of the driver's suspension, in metres per newton (the reciprocal of its 'stiffness').
*<math>R_{\rm ms}</math> – The mechanical resistance of the driver's suspension (i.e., 'lossiness'), in N·s/m.
*<math>L_{\rm e}</math> – Voice coil inductance, in henries (H) (typically measured at 1&nbsp;kHz for woofers).
*<math>R_{\rm e}</math> – DC resistance of the voice coil, in ohms.
*<math>Bl</math> – The product of magnetic flux density in the voice-coil gap and the length of wire in the magnetic field, in tesla-metres (T·m).