Why are the fluorescence intensities of the HSV detection markedly lower than those of the HSV-1 detection using the artus® HSV 1/2 LC PCR Kit?

The artus^® HSV-1/2 LC PCR Kit contains probes for both the HSV-1 and HSV-2 detection. Yet, the hybridization properties of these probes differ with the template DNA (HSV-1 or -2) to allow for a melting curve based virus type discrimination. The probes which match HSV-1 perfectly carry a few mismatches for HSV-2 leading to decreased fluorescence signal.