Effective Tip Mass
Effective tip mass is the moving stylus system’s resistance to acceleration, expressed as an equivalent mass at the record-contact point. It is usually quoted in milligrams (mg).
Also called equivalent tip mass, it includes the effect of the moving assembly, not just the diamond. Where that mass sits matters: mass near the tip contributes more than mass near the pivot.
Effective Tip Mass — Cartridge
Lower effective tip mass can help the stylus follow rapid, high-frequency groove movement. It does not guarantee better tracking or sound quality: stiffness and damping, which controls vibration, also matter. Look at measured tracking performance alongside this figure.
Cartridge weight describes the whole cartridge; tonearm effective mass describes the arm. These separate quantities concern arm/cartridge matching. For tip-mass comparisons, check that both manufacturers describe the same quantity on a comparable basis. If that basis is unclear, avoid ranking the cartridges by the numbers.