I have been reading with much interest the latest threads about arm length. There was some discussion about moment of inertia, cartridge compliance, etc. It seems to me that the various resonance frequency calculators are fairly basic. They ask for the arm's effective mass, the cartridge plus mounting hardware weight and the cartridge compliance, but it seems much more complicated than that.
I have been playing with the dampening trough of my SME arm recently and have observed how this effects sound. It seems to me that many factors can influence the cartridge/arm match up and overall sound of the combination:
1. Where the counterweight is located in relation to the arm's pivot point which effects inertia,
2. Where the mass of the armtube is concentrated (straight tube or tapered away from the bearing),
3. The length of the arm versus the weight of the cartridge effecting inertia,
4. Is additional fluid damping being used, at the cartridge end or near the pivot,
5. Bearing type in the arm.
There may be other factors.
I am noticing that because my two cartridge have a difference in weight of 2.0 grams, have different compliances, 8 vs. 10, that some of the differences in sound may be related to how my 12" arm moves which is a result of its changing effective mass, the changing moment of inertia, and the dampening with which I am experimenting.
I guess the calculators are a starting point, but there are many factors which contribute to a good tonearm cartridge match and for optimizing the performance of the system.
I have been playing with the dampening trough of my SME arm recently and have observed how this effects sound. It seems to me that many factors can influence the cartridge/arm match up and overall sound of the combination:
1. Where the counterweight is located in relation to the arm's pivot point which effects inertia,
2. Where the mass of the armtube is concentrated (straight tube or tapered away from the bearing),
3. The length of the arm versus the weight of the cartridge effecting inertia,
4. Is additional fluid damping being used, at the cartridge end or near the pivot,
5. Bearing type in the arm.
There may be other factors.
I am noticing that because my two cartridge have a difference in weight of 2.0 grams, have different compliances, 8 vs. 10, that some of the differences in sound may be related to how my 12" arm moves which is a result of its changing effective mass, the changing moment of inertia, and the dampening with which I am experimenting.
I guess the calculators are a starting point, but there are many factors which contribute to a good tonearm cartridge match and for optimizing the performance of the system.
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