How to measure tonearm effective mass


Some of us who use high or low compliance cartridges fret about mating them with tonearms of low or high effective mass, respectively. Most of us rely upon data supplied by some manufacturers to specify the effective mass of their tonearms, but many manufacturers do not even supply such data. Does anyone know a simple and relatively accurate method for determining effective mass? We know what "effective mass" is; we want to know how to measure it.
lewm
Yes, thanks Lewm. I should have added, "adjusted to some degree", or some such. ;-)
Hi Mark,

I've been following this topic (motor controller) for a while now. There's obviously a great deal of interest from a growing number of turntable owners in finding a better way to extract the most music from their equipment. Is there any plan to share your design with a wider community by making it available to the DIYers in some fashion?
Cheers,
~james
James, This is/was a thread about tonearm effective mass. I think you want to post on the thread about "Garrard" motor controllers. It's possible that Mark intends to sell his Garrard/Lenco controller.