SL-1200G/Hana ML Best Headshell

I don’t remember where I came up with the number, but according to my spreadsheet, I listed the 1200G arm with a 12g effective mass. That puts it low on the spectrum.  The stock headshell is very light. After using the 12g number and calculating all of my carts, I found that the resonant frequencies were within tolerance for all but the heaviest of headshell / cart combos. I use the ML with a version of the Zupreme mentioned above. There are several sellers of the same piece. No issues. I think that headshell is listed around 10g, but in practice it’s a bit more. I looked at the Titanium too - I thought it would be too heavy. 

I have a bunch of the original Jelco magnesium headshells (LP Gear equivalent) and have compared them to carbon fiber headshells. The CF had cleaner, better delineated bass but diminished highs with slightly less dynamics. Overall, I stuck with the magnesium. 

If you look at the math, there is really quite a bit of leeway in effective mass and compliance that will give you a resonant frequency that falls within the typical range of 8 to 12Hz.  And anyone who has done vinyl for a long time with a variety of cartridges and tonearms will tell you that you can get away with a slightly lower lower limit (lower than 8Hz, that is).  The first reason is that the Fr is dependent upon the square root of the effective mass times the compliance.  Taking the square root has the effect of blunting differences.  (To understand what I mean, go on line and use one of the Fr calculators.  Plug in some extreme values for M and C and note how relatively little that affects the results.)  The second reason is that one really does not know and cannot easily know true accurate values for M and C for YOUR tonearm and YOUR cartridge, unless you empirically determine C and go through an arduous calculation for M, instead of using numbers given to us by the various manufacturers, which are average values at best. (I don't think every cartridge X has exactly the compliance that its manufacturer tells us it has, even out of the box, but especially if it is vintage or well used.) So, in the end, "just try it" is a good rule of thumb. 

I have read that the technics  arm was tested to have a 9g effective mass.  

the stock headshell has a lighter mass than most if not all aftermarket head shells, something i have found valuable trying to match cartridges.  

another plus for the stock headshell is that it has a low cartridge mounting surface.  most aftermarket headshells have a higher cartridge mounting surface.  this could prevent setting a level cartridge and proper VTA because the arm height adjuster runs out of travel resulting in too much tail up.  

this would mean using a much thicker mat or cartridge shims.  

No, the Technics SL1200 tonearm has an effective mass of 12g

The OEM headshell is 7.6g.