Hi Fi Cartridge Compliance and Tonearm Effective Mass

Do Cartridge Compliance rules always hold true?

Some say you need to match your cartridge compliance with a specified tonearm effective mass. The recommended effective mass is sometimes specified by cartridge manufacturers. If not there are formulas which calculate the theoretical optimum. In practice we have found that our arms are unusual. They work seriously well whatever they are put with. The reasons for this may slay a few sacred cows.

Cartridge compliance calculations are an overrated simplification of complex problems. For example the vertical compliance is sometimes different to the horizontal compliance but this is not stated. As far as compliance issues go – Origin Live and many dealers find theory bears little or no relation to reality. This view is now increasingly held. There are too many surprising experiences where theoretical optimums mis-track and theoretical mismatches track perfectly.

For example The Cartridge Man will tell you that his cartridges do not track in the SME V arm even though the effective mass of 10.5 grams is PERFECT for the compliance of his cartridges. On the other hand our Silver MK1 arm at 16 grams tracked his music maker and all other cartridges with no problems.

Origin Live tonearms are an exception

Clients frequently ask us about cartridge compliance and the best match for our arms. The advice we offer never causes problems. Ignore cartridge compliance because tonearm effective mass is a non issue for our arms. This is because a properly designed tonearm is affected by compliance effects far less than would otherwise be expected.

Proof of this claim is found by many clients who invariably state that a change to one of our arms upgrades the performance of their cartridge. This remains true whatever their cartridge and previous tonearm. In other words compliance is well down the scale of significant factors to the point of irrelevance in a good arm. You may find those who will argue with this but they always seem to relate matching issues they’ve had with other arms and not an Origin Live one.

Our Research into Cartridge compliance

We’ve experimented with cartridge compliance / tonearm effective mass, using London Decca cartridges. These are far more prone to mistracking than most and hence very fussy about arms. The ideal effective tonearm mass for these cartridges is 25 grams and yet they track as normal in our 13 gram effective mass tonearm. This is highly unusual. We then added weight to the headshell to increase effective tonearm mass up to 25 grams. Although performance in the bass did improve, it was fairly minor. The Conclusion is that cartridge compliance is only a small factor among many other far more important aspects of tonearm design.