If you put the information of the arm and cartridge this chart will give you an idea of the compatibility !
You need to know what exact model of SME 12-inch tonearm that you are about to buy. Is it the 3012, the 312, or there’s even a third possibility, I think? Then you need to look up the effective mass of that particular model tonearm. Then too, you want to find out what is the compliance of the Benz Micro Ruby cartridge. One or both of these parameters is probably available from SME, Benz, or Vinyl Engine. After you have a handle on that, you can calculate the resonant frequency, which should be between 8 and 12Hz. The equation is available on line. OR, you can just wing it. There’s really a lot of leeway in the numbers that work. Anyway, report back with the numbers, and we can move on from there.
Here's what I found with links to all pertinent info:
The exact model of tonearm is SME M2-12R.
Per this post, the tonearm has an effective mass of 18 grams.
Per Vinyl Engine, compliance for the Benz Micro Ruby is 15.
The cartridge weight is 8.6 grams.
Using this calculator, I get a frequency of 7.968.
So, based on your recommended windows if 8-12 Hz, this would be a subpar pairing? Am I interpreting that right?
I don’t see any problem . Here is some more information on cartridge and arm compatibility. You don’t want to go too far above or below 8-12 hz!
Thoroughfare, This is far from an exact science, even though using that fancy equation may suggest a level of trust, that trust is not warranted. 7.9Hz should be fine. The "lower limit" of 8Hz is suggested to keep the resonance out of the range of footfalls or other in-room disturbances or record warps. The upper limit is to keep the resonance away from the audio band. 8-12Hz is merely a rule of thumb. Go for it.