Swinging Tonearm

During the development of the new tonearm for a Swiss client,we had to think about a new method to measure the resonances in a tonearm tube. exciter The literature and the Internet did not help us a lot. Black Art,Voodo,all sorts of different philosophies,but no real engineering approach. At the end,we dicided to do our own measurement setup,using our Scanning Laser Vibrometer and a self made exciter ( photo on the left).

This exciter was a NXT exciter in it’s previous life and with the weight of 6g including fixing bar close enough to a half way normal cartridge.

It was very exiting for us to see the results. First of all,it was surprising that we had strong resonances in the region around 6-8kHz and not only at a few hundred Hz as everybody was expecting.

Here are two examples:

771 Hz

7.1 kHz

Below,you can see the spectrum of the resonances in a 10 mm Aluminum tube with 1mm wall thickness.

spectrum-nackt

The next picture shows the result after we added compliant mass absorbers and surface damping:
spectrum-fertig1

More information will be posted,once the product is out in the market. Introduction is in Munich on the High-End Show 2009