Effective mass is the summation of the mass at each point of the tone arm times
the distance from that point to the pivot. In other words, it is an integral of the
mathematical function which describes the tone arm, the headshell, the cart,
and the counter weight. Since that mathematical function is unknown to us,
it is very difficult if not impossible to calculate the effective mass accurately.
Perhaps other members with better math skills can come up with a way to
estimate that.
One way to find out how much more weights are needed is by trial and error.
You can incrementally add some weight to the headshell, make all the VTF
adjustment necessary, and play a test record to see if the resonant frequency
falls within the ideal range.
the distance from that point to the pivot. In other words, it is an integral of the
mathematical function which describes the tone arm, the headshell, the cart,
and the counter weight. Since that mathematical function is unknown to us,
it is very difficult if not impossible to calculate the effective mass accurately.
Perhaps other members with better math skills can come up with a way to
estimate that.
One way to find out how much more weights are needed is by trial and error.
You can incrementally add some weight to the headshell, make all the VTF
adjustment necessary, and play a test record to see if the resonant frequency
falls within the ideal range.