Impedance measurement results: Sharp CP-1600H (RW)

[Bootstrapper]

Hi fellows,

I had some time today after work and run a couple of quick impedance measurements with an old Sharp loudspeaker I had. The measurements were done using frequency response analyzer from Venable Instruments.

I did drive a sine signal (amplitude 100 mV) from 1 Hz to 1 MHz into the speaker while measuring the speaker current with a decent current probe and the speaker voltage with another probe. The results are shown in the attachments. The results could have been more accurate had I used larger signal and smaller frequency step, but at this time these seemed sufficient.

The impedance & phase vs. frequency

The gain & phase vs. frequency

The specs on the speaker itself says that the nominal impedance is 4 ohms. Well, the measurements show a bit other value..

p.s. This isn't supposed to be any big science, just pure fun (combined with extra time and equipments!)