Technical Parameters Of The Speaker

The parameters of the speaker refer to the specific performance parameter values ​​of the speaker tested by a dedicated speaker test system. The commonly used parameters mainly include: Z, Fo, η0, SPL, Qts, Qms, Qes, Vas, Mms, Cms, Sd, BL, Xmax, Gap gauss. The following are the physical meanings of these parameters.
Z:
Refers to the impedance value of the speaker, including: rated inductance and DC resistance. (Unit: ohm/ohm), usually refers to the rated impedance.
The rated impedance Z of the speaker: It is the minimum impedance modulus after the first maximum value of the impedance curve, that is, the impedance value corresponding to point B.
It is the basis for calculating the electric power of the speaker.
DC resistance DCR: It refers to the impedance value tested when the voice coil is stationary and a DC signal is passed. What we usually call 4 ohms or 8 ohms refers to the rated impedance. (ACR AC impedance: the resistance measured under the dynamic state of the voice coil)
Fo (minimum resonance frequency): It refers to the frequency corresponding to the first maximum value of the speaker impedance curve. Unit: Hertz (Hz) The impedance curve of the speaker is a curve of the impedance modulus of the speaker measured by the constant current method or constant voltage method under normal working conditions.
η0 (speaker efficiency): refers to the ratio of the speaker's output sound power to the input electrical power.
SPL (sound pressure level): refers to the sound pressure generated by the speaker when the rated impedance 1W electric power is passed through the speaker. At a point 1m away from the speaker on the reference axis. Unit: decibel (dB).
Qts: The total quality factor value of the speaker.
Qms: The mechanical quality factor value of the speaker.
Qes: The electrical quality factor value of the speaker.
Vas (effective volume of the speaker): refers to the volume when the acoustic compliance of the air enclosed in a rigid container is equal to the acoustic compliance of the speaker unit.
Mms (vibration mass): refers to the sum of the masses of the various components participating in the vibration of the speaker during movement, including the drum paper part, voice coil, elastic wave. Unit: gram. And the mass of air participating in the vibration, etc.
Cms (compliance): refers to the flexibility of the supporting components of the speaker vibration system. The larger its value, the softer the entire vibration system of the speaker. Unit: mm/N
Sd (vibration area): refers to the effective vibration area of ​​the drum paper/diaphragm during the vibration of the speaker. Unit: square meter (m2).
BL (magnetic force): the product of the gap magnetic induction intensity and the effective voice coil line length. Unit: (T*M).
Xmax: the linear travel of the voice coil during vibration. Unit: mm.
Gap Gauss: gap magnetic induction intensity value. Unit: Tesla.