Cartridge
My spec sheet gives a different compliance figure
The formula needs the dynamic compliance measured at 10 Hz. A 100 Hz figure (common on Japanese spec sheets) makes the result read too high; a static figure makes it read too low. Period measurements suggest 100 Hz figures sit around 1.7 to 2× below the 10 Hz value, but no published factor is exact: treat any converted number as an estimate and lean on the verdict band rather than the decimal.
Tonearm
Effective mass is the arm’s inertia seen at the stylus, published by the arm maker; it is not the arm’s weight. For arms with a detachable headshell, the published figure includes the standard headshell: if yours is different, enter the weight difference (heavier is positive, lighter is negative). Hardware covers screws and washers; 0.5 g is typical.
Resonant frequency
-- Hz
Enter your figures to see the result.The window is bounded on both sides by physics that was measured, published and argued out in the engineering press. Below about 8 Hz the arm rides the energy of record warps and footfalls (warps cluster between 0.5 and 10 Hz, strongest near 3 to 4 Hz: Wireless World 1967, Audio 1978). Above about 12 Hz it edges toward the lowest recorded bass (Wireless World 1966, High Fidelity 1972). The 1960s designers aimed near 15 Hz; the modern, lower band is a practical optimum shaped by the high-compliance era.
The figure is the vertical, or average, case; lateral resonance typically sits a little lower (Wireless World 1966). This calculation locates the resonance. It does not predict how severe it will be. Two pairings can share a resonance frequency and still differ in how sharply they resonate, because severity depends on damping (Q), which this formula does not contain. That, plus how the arm handles warps, is the rest of the story.
Compliance chart
Total effective mass (tonearm + cartridge + hardware, plus any headshell difference) across the top, dynamic compliance at 10 Hz down the side. Highlighted cells fall in the 8 to 12 Hz window.