How to find spring constant & damping coef of speaker flexure

[ivan6496]

Hi anyone,

I'm doing my final year project requires to use audio speaker. I need to know the two parameters for my transfer function. They are spring constant and the damping coefficient of the speaker flexure. Can anyone give me some idea?

Best Regards,
Ivan

[berkeman]

Just use a small force-measuring device to measure the displacement for a range of forces. That will give you the k value. You could even just turn the speaker vertical and set small weights on it and measure the displacement with calipers.

As for the damping coefficient, maybe you can tap it (the center of the cone) and measure the output from the speaker with an oscilloscope. Capture the damped sinusoid output (probably fairly small for light taps), and calculate the damping coefficient from that waveform.

[ivan6496]

Hi Berkeman,

Thanks for the help. Appreciated.

Best Regards,
Ivan:smile:

Just use a small force-measuring device to measure the displacement for a range of forces. That will give you the k value. You could even just turn the speaker vertical and set small weights on it and measure the displacement with calipers.

As for the damping coefficient, maybe you can tap it (the center of the cone) and measure the output from the speaker with an oscilloscope. Capture the damped sinusoid output (probably fairly small for light taps), and calculate the damping coefficient from that waveform.