Vibration Modes in a loudspeaker

Pianomaxx · Post by **Pianomaxx** » Sun Jan 28, 2007 2:03 pm

Hello folks,

recently we did an holographic experiment in university, and I wanted to show you this as an example for scientific use of holography!

This is the 3,0-Mode which is induced in a loudspeaker by a certain frequency. At other frequencies and amplitudes you can find many other Eigen-Modes of the loudspeaker. It's done via time-average and realtime- interferometry.

(Stereo-View)

glajciorz · Post by **glajciorz** » Sun Jan 28, 2007 2:18 pm

Good day.

Piano, was your setup like Gabor's one (http://nobelprize.org/nobel_prizes/phys ... iedermann/, second image from the bottom of the page) ?

How did you isolate your optical bench from wibrations induced by loudspeaker ?

greetings

Adam

Pianomaxx · Post by **Pianomaxx** » Sun Jan 28, 2007 3:29 pm

Hello Adam,

yes, in principle it's the same setup like Gabor's one. But we had a big, variable beamsplitter to adjust the ratios. We used 2:1 for reference:object intensity on the plate.

The loudspeaker is put on a heavy mass and I think, the table is made of granite or marmor which suppresses the propagation of vibrations very well.

best regards,

Max