Okay so I searched all over the Web for the resonance frequency of my car speaker so I can properly apply crossover filters, but didn't found any reference of the resonance frequency of this speaker model.

So how can I calculate it?

I have the following data:

Peak power: 150w Rms power: 20w Response Frequency: 90Hz-20kHz Sensitivity: 91db/W/m 4 ohm

Thank you in advance!!

  • \$\begingroup\$ There are many resources online that detail this process (simply search "finding speaker resonant frequency"), but briefly: you can use a waveform generator and oscilloscope to measure voltage across the speaker as a function of frequency. \$\endgroup\$
    – uint128_t
    Dec 4, 2016 at 7:18
  • 2
    \$\begingroup\$ Disconnect Amp. apply 9V on off and record thump wave then analyze using Audacity >tools>spectrum analysis. That is it. also if you don't know impedance, measure DCR and approximately double that. \$\endgroup\$ Dec 4, 2016 at 7:39

1 Answer 1


You cannot CALCULATE Fs, (Resonant frequency of loudspeaker moving mass in free air). But you can MEASURE it relatively easily. You will need a power amp, a variable frequency source, and a DMM. THere are many resources online for measuring driver characteristics. Fs is one of the primary measurements for the popular Thiele/Small parameters. Here is one straightforward explanation:

Ref: https://sound-au.com/tsp.htm

  • \$\begingroup\$ Thanks for your answer, actually that's too hard for me lol. I will instead contact the manufacturer and ask them about the speaker Fs :) \$\endgroup\$
    – TiagoM
    Dec 5, 2016 at 1:00
  • \$\begingroup\$ I though there was a simple math that could give me Fs. Thank you very much! \$\endgroup\$
    – TiagoM
    Dec 5, 2016 at 1:01
  • \$\begingroup\$ To be fair @RichardCrowley: I'm sure you can calculate Fs, it's just much easier to measure it. \$\endgroup\$ Feb 2, 2017 at 17:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.