What defines a high compliance cartridge vs low

High compliance in the old days was 50 or better. These days I would say anything over 25 would be high. Under ten would be low. There is no absolute standard and as you see it changes with time. The relationship between arm mass and cartridge compliance will determine the resonance of the combination. I have usually seen figures between 10 and 20 Hz given as desirable. Too low to interfere with musical signal and too high to cause low frequency problems. The formula for determining resonance frequency is on Vinyl Engine in a far more complete form than I could attempt here. I have noticed that many on here pay little attention to it, using fairly high compliance MM cartridges in quite heavy arm or low compliance MCs in lower mass arms so they should be taken as guidelines rather than commandments.

In fact there HAS been a considerable reduction in compliance since 1980; you can see this by looking at Shure cartridges using the old HiFi Choice tests, the most exhaustive ones ever done. The Shure V-15 3 was measured in 1977 as having a compliance of 40; by 1980 the V-15 3 HE had risen to 53. But in the same issue the Type 4 was only 32. And in 1982 the type V was measured at 25, half that of the 3 HE. In the late 70s the compliance race that had been going on for years reached its climax and retreated to the more sensible levels we see now. In earlier days even many MCs like the Dynavector had compliance's above 25.