Jeremy,
Halcro said it more succinctly than I. That's what I mean. Resonance calculators are just an estimate. I've calculated combinations that should resonate at 8Hz, and they tested at 10Hz. Effective mass is will change with things like the distance of the counterweight from the pivot (moment of inertia). Cartridges might vary somewhat or age. If you're really interested in the math I suggest that you go to Vinyl Engine and do a search or ask in the forum.
Re: 100Hz conversion. There doesn't seem to be an exact formula for conversion. Carts in the 10cu range (100Hz) have 10Hz cu approx 1.75 x that. The AT-150MLX, 33EV (10cu @100)have cu = 18 approx. An AT-95 or Clearaudio MM has 6.5cu @100Hz and approx 15cu at 10Hz. The DL-103 has 5cu at 100, and seems much stiffer. An old Pioneer PC-401MC has static cu of 16 and 100Hz dynamic of 12cu. VTF range (1.7 - 2.3) would indicate a stiff suspension. None of this makes much sense for arm matching. 100Hz cu seems more like a measure of tracking ability at 100Hz (bass), than cu around res freq which is near 10Hz. The only correlation I can come up with is a sliding scale. Low 100Hz cu is more than doubled for conversion. Med - 10cu is x 1.75. Higher, around 12 to 16 @100 is closer to to that number.
There are other things to consider as well. Certain combinations will work better, in some cases, than others, even though compliance/mass would seem OK. That's why it's really more effective to ask or read what the best matches are.
Regards,
Halcro said it more succinctly than I. That's what I mean. Resonance calculators are just an estimate. I've calculated combinations that should resonate at 8Hz, and they tested at 10Hz. Effective mass is will change with things like the distance of the counterweight from the pivot (moment of inertia). Cartridges might vary somewhat or age. If you're really interested in the math I suggest that you go to Vinyl Engine and do a search or ask in the forum.
Re: 100Hz conversion. There doesn't seem to be an exact formula for conversion. Carts in the 10cu range (100Hz) have 10Hz cu approx 1.75 x that. The AT-150MLX, 33EV (10cu @100)have cu = 18 approx. An AT-95 or Clearaudio MM has 6.5cu @100Hz and approx 15cu at 10Hz. The DL-103 has 5cu at 100, and seems much stiffer. An old Pioneer PC-401MC has static cu of 16 and 100Hz dynamic of 12cu. VTF range (1.7 - 2.3) would indicate a stiff suspension. None of this makes much sense for arm matching. 100Hz cu seems more like a measure of tracking ability at 100Hz (bass), than cu around res freq which is near 10Hz. The only correlation I can come up with is a sliding scale. Low 100Hz cu is more than doubled for conversion. Med - 10cu is x 1.75. Higher, around 12 to 16 @100 is closer to to that number.
There are other things to consider as well. Certain combinations will work better, in some cases, than others, even though compliance/mass would seem OK. That's why it's really more effective to ask or read what the best matches are.
Regards,