I just came from the H/K website. They claim a triple crossover, but it is only high pass. Then a seperate low pass must be selected for the sub. H/K cautions that the subs low pass must be set at the highest of the triplc crossover settings to avoid creating a bass hole. This would indeed cause a bass doubling in the mains if they were set to crossover at a frequency lower than the sub's crossover. Why the hell would they do something stupid like that???