In conversations in the past I have come across people who actually say they can't hear a difference using alnico magnets!
IMO, based on the success of the Klipsch heritage line, there are, and for a long time have been a LOT of people that just can't hear, period!

There are many other speakers that fit this bill too, i don't mean to pick on Klipsch exclusively. Heck, i even like Cornwalls and properly set-up K-horns from ~500hz down.