When selecting either MC or MM cartridges for your record player, total effective mass of tonearm (including cartridge and headshell) has to be taken into account in relation to the mechanical compliance (elasticity) of the cartridge cantilever system.
The high mass of the combination needs low mechanical compliance, otherwise record warps can easily provoke tonearm vibrations at frequencies around 4 to 6 Hz, that will bring degradation of performance (at least 8 Hz is advisable)
A phono cartridge with the compliance in the range of 5 to 10 µm/mN is considered as a very low compliance cartridge, a cartridge with the compliance in the range of 10 to 20 µm/mN is moderate compliance cartridge and a cartridge with the compliance value above 35µm/mN is very high compliance cartridge.
Low mass arms mate well with both moderately high and very high compliance phono cartridges.
A tonearm whose effective mass is rated at 10 grams or below is considered low mass (e.g. early SME’s, Grace 747, Ortofon AS-309S, RS-309D, TA-110 and TA-210).
Moderate mass tonearms are good companions for moderate to low compliance cartridges.
A tonearm whose effective mass is rated between 11 and 25 grams is considered moderate mass (e.g. SME IV, IV, V, VI, Triplanar, Graham). Arms above 25 grams of mass are high mass in nature (Eminent Technology, Dynavector).
If a low compliance cartridge is used with a low mass tonearm, undesirable resonances can occur in the audible range.
When a high compliance cartridge is mated with a moderate mass tonearm, resonances in the infrasonic range may occur.
The below scheme illustrates the relationship between cartridge compliance, tonearm mass and the resulting resonance frequency.