Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

DC Resistance (Ω)

Voice-coil DC resistance (Re).

Qms Factor

Mechanical Q factor Qms; must be positive.

Qes Factor

Electrical Q factor Qes; must be positive.

Estimate a loudspeaker driver's low-frequency impedance peak as Zmax = Re x (1 + Qms / Qes), neglecting voice-coil inductance. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Peak Impedance (Ω)

Impedance magnitude at free-air resonance.

• Loudspeaker impedance, sensitivity, enclosure volume, crossover, and SPL depend on frequency, driver parameters, baffle and room acoustics, thermal compression, excursion, distortion, and measurement distance. Nominal impedance is not constant resistance.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Common-Mode Choke Impedance

  Estimate one winding's series RL impedance magnitude at frequency f as √[R²+(2πfL)²]. Enter the effective common-mode inductance and resistance at the operating point; real choke impedance also includes core loss, capacitance, and self-resonance.

• Ideal Capacitor Impedance

  Calculate ideal capacitive reactance Xc=−1/(2πfC) and its magnitude in ohms. ESR, ESL, leakage, and self-resonance are not included.

• Decap Resonance

  Compute the resonant frequency in megahertz of a decoupling capacitor from its mounted series inductance in nanohenries and capacitance in nanofarads.