Which tonearm with a Soundsmith The Voice?

I saw a used Schroder #2 9" arm with a Pertinax armwand for sale, but unfortunately not on Audiogon.

where was this 2 for sale?

22 cu is the same as an Ortofon 2M. There are plenty to choose from that are less than 12g. Even a little more than 12g should be fine if your set-up isn't prone to feedback.

An arm with mass lower than recommended (Black Widow) isn't a good idea. If the effective mass is too low, the resonant frequency goes above the recommended range and can cause intermodulation distortion. This would be especially true in an arm w/o fluid damping.

Origin Live Silver or Zephyr should be good (12g), and also a Moerch with a yellow arm tube. Some people rave about the Audiomods arm from UK, sold direct. There are plenty of excellent used and vintage arms. You have to hunt.

Regards,

I run the vinyl engine tonearm effective mass calculator using 2 gr as mounting hardware (Soundsmith's aluminum screw set) and got the following results for the desired resonance between 8 to 12 Hz (-.82 to 9.16 gr). -.82 gr.: a negative number! there is no lower limit!!! This doesn't correspond with some of the suggestions I have seen. Some suggestions are for 11 or 12 gr. so, practical mass differs from calculated mass. What else is to be considered to determine ideal mass?

There is no ideal mass. Those calculators are only an estimate anyway, results may vary. You could buy a mediocre arm and have an "ideal" resonance of 10Hz, and it would be outperformed by a higher quality arm where the resonance is outside of the recommended range.

What did Soundsmith say, Schroeder? If that's not doable, you should get as close to that quality as possible within your budget. A resonant frequency of 7.4Hz is not a problem.
Regards,