Why would you make such a strong statement? If a filter improves the overall performance of the system, why not use it? Would you rather listen to an unbalanced overly bright shouting full range speaker system and be happy knowing it is still "pure" due to the lack of any filter while it continues to hurts your ears?

Not me, I'll take the filter. A filtered full range is still much better then a two way in my opinion, and also better then an unfiltered full range in most cases. I have successfully designed and built both multi-way and single driver systems and really prefer the filtered full range Lowthers.

Martin