Model   Fs  Qts  Qms  Qes   Vas  Eff   Pe   Xmax  Re   Le    Sd    BL  Mms Flux

    Fs    Resonance frequency of driver in free air                                                    hertz

    Qts    Total Q of driver at Fs including all driver loss mechanisms                            --

    Vas    Volume of air having the same acoustic compliance as driver suspension    liters

    Eff    Reference efficiency (half space acoustic load)                                            %

    Qes    Q of driver at Fs considering electrical losses only                                      --

    Qms    Q of driver at Fs considering mechanical losses only                                  --

    Le     Voice coil inductance                                                                                mH

    Pe    Thermally-limited maximum electrical input power                                         watts

    Xmax    Peak linear displacement of driver diaphragm                                         millimeters

    Sd    Effective projected surface area of driver diaphragm                                    square meters

    Re    dc resistance of driver voice coil                                                                 ohms

    BL    BL product                                                                                                 T*m

    Mms    Effective moving mass                                                                             grams

    flux    Flux density                                                                                               Tesla