Figuring Cartridge Compliance.. Help!

Surely it does not work, because you need a compliance figure at 10Hz  (not at 100Hz). But don’t worry, to convert it simply multiply on 1.7

Your cartridge dynamic compliance is about 8.5 cu @ 10Hz

P.S. If you like low compliance cartridges and heavy tonearms then do yourself a favor look for Fidelity-Research cartridges and arms instead of that oldschool Denon with awful conical tip. 

FR cartridges have Contact Line "Vital" diamonds like this one on PMC-3 (Air Core Coil). 

Dear @coachpoconnor :  I don't know which tonearm you have but the 103 is not really a to problematic cartridge .

You can use really " safe " a tonearm from 12grs. ( even a little lower. ) and up and will stay inside/around the normal resonance frequency range.
It's more important that your tonearm be a good damped design.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

And if you really want to measure an exact cartridge/tonearm resonance practically (not theoretically) you need a Hi-Fi News Test LP 

Chakster... Thank you, I do plan to buy the test LP you suggest.
I bought a Harmon Kardon T65C in very good condition at the suggestion of an audiophile acquaintance. I really did not plan on putting the DL 103 on this turntable; but the other night I hooked it up to see how it would sound, out of curiosity. I have since listened to it for approximately 30 hrs. Last night I attached 2 gms to the head shell (and adjusted the counter weight accordingly) and it seemed to make a qualitative difference in sound. It got me interested in understanding how to calculate effective mass. I have seen some brass counterweights and brass head shell weights, that I also thought I would experiment with. But I am interested in learning to do the Math behind these theories.
rauliruegas- I believe that the effective mass of this Ito Microrace tonearm is 9.5.