Tools · Tonearm register

Naim ARO

Effective mass

11 g

Bearing Unipivot
Pivot to spindle 212.5 mm The mounting distance — where the arm sits relative to the platter.
Overhang 18 mm
Effective length 230.5 mm Pivot to stylus: the mounting distance plus the overhang.
Offset angle 23.92° Naim publish no offset angle. This is worked out from the effective length and the Baerwald (Löfgren A) · IEC geometry the arm's published overhang follows — treat it as accurate to a few hundredths of a degree, not as a maker's figure.
Mounting Dedicated ARO armboard
Source stereophile.com Not yet checked against a primary source — treat as indicative.

Effective mass is not what the arm weighs. It is the mass the cartridge has to accelerate at the stylus tip, and with the cartridge's compliance it sets where the pairing resonates — ideally between 8 and 12 Hz. Add 0.5 g for mounting hardware when you work it out.

Naim and ARO are the trademarks of their owner. Bool Audio is independent of them, and this page is not endorsed by them.

Who makes these

Bool Audio is a father and son making hi-fi components in a small UK workshop. We build the Clear Wave unipivot tonearm and the Clear Wave 2.0 tonearm cable, both for the Linn LP12. These calculators began as our own bench arithmetic. They are free to use, there is nothing to install, and they take no view on which cartridge you should own.