We present a multi-waveband analysis of a 126-galaxy sub-sample of the 12um galaxy sample (12MGS), for which we have carried out a detailed X-ray spectral analysis in a previous paper. We determine the activity class of the galaxies by way of optical-line ratio diagnostics and characterize the optical classes by their X-ray, 12um and [OIII] luminosities and X-ray spectral properties.