It is not necessary to recalibrate after updating, but you may miss out on some new features. If you want the full benefit of the new update, then you should go through a complete calibration process.

The new GLM 4.2 version has a host of new features, most notably the GRADE report and MIDI capabilities. It also has new firmware updates and bug fixes. For more detail on the improvements with version 4.2, please refer to the Release Note. In order to get the new GRADE report, you must perform a calibration while signed into your Genelec Community account.