| Parameter | Unit | Description |
|---|---|---|
| Q_ | ? | Electrical damping. Lower value means higher damping. Describes a drivers ability fo resonate at based on electrical means. |
| Q_ | ? | Mechanical damping. Lower value means higher damping. Describes a drivers ability fo resonate at based on mechanical means. |
| Q_ | ? | Total damping (parallel coupling of both and Q_ |
| V_ | Equivalent volume of air to C_ | |
| f_ | Free-air resonance frequency of driver |
| Parameter | Unit | Description |
|---|---|---|
| M_ | ? | Mechanical mass of the vibrating part of the driver including air load |
| C_ | ? | Compliance of driver (inverse of spring stiffness) |
| R_ | ? | Mechanical damping, as in the damping of the diaphragm arising from mechanical friction, including the resistive part of the radiation load |
| R_ | DC resistance of the voice coil | |
| ? | Magnetic induction crossed with wire length in the air-gap (cross product) | |
| ? | Diameter of diaphragm | |
| Voice coil inductance | ||
| ? | Surface area of diaphragm | |
| f_ | Hz | Frequency at which and is to be determined |
| K_ | H\cdot \sqrt | Voice coil semi-inductance after Vanderkooy |
| Parameter | Unit | Description |
|---|---|---|
| X_ | Max linear excursion, usually calculated as and sometimes multiplied by a factor (1.15 or 0.87, depending on how much distortion is accepted) | |
| X_ | Damage limit excursion, also a peak value | |
| Height of the voice coil | ||
| Height of the air-gap between the voice coil and the magnet | ||
| Volume displacement, i.e. how much air the driver can move in its linear range | ||
| Thermal limited max. continuous electric power handling. If a driver is driven continuously above , then it will eventually fail. |
| Parameter | Unit | Description |
|---|---|---|
| Efficiency | ||
| Z_ | $?\Omega | Nominal impedance of the driver |
| Efficiency in deciBell per 2.83V | ||
| Efficiency in deciBell per 1 Watt |
| Parameter | Unit | Description |
|---|---|---|
| Resistance temperature coefficient of the voice coil material. Normally, copper has AlfaVC of about 0.0039 1/K at +20 °C. | ||
| Thermal resistance of driver from voice coil to ambient box air | ||
| Thermal capacity of driver voice coil assembly |
| Parameter | Unit | Description |
|---|---|---|
| SPL_ | how loud driver can play in closed box or infinite baffle into half-space at maximum excursion at 20 Hz. Distance from this imaginary baffle is 1 meter. It gives "feeling" on . Note also, that it doesn't apply to vented or any other assisted enclosure. | |
| SPL_ | Maximum thermal limited SPL (at maximum , assuming power compression = 3 dB) playing into space. | |
| R_ | \frac{N\cdot s} | Electromagnetic damping factor (the unit for viscosity), gives you the mechanical control/damping of the diaphragm arising from the electro-magnetic motor system. is related to in a way similar to how is related to . is often used as a measure for power of the magnetic motor system, see and . |
| (Gamma) | \frac{m} | The acceleration factor (acceleration per ampere) |
| M_ | Motor power-factor. is independent of the drivers impedance level, and therefore does not prioritize high or low impedance drivers. is purely a motor system power-factor. | |
| M_ | or \frac{kg} | Motor cost-factor. Expresses how powerful the motor system is (based on , and either or depending on whether the voice coil is overhung or underhung), and the value includes an indicator of how much efficiency is "lost" in the design. |
| Efficiency-Bandwidth-Product |