Audiophiles are often going for "as much detail transparency as I can get." And so they often take grills off. What often happens, especially in speakers designed with grills, is a slight change in tonal balance where the upper frequencies get a bit more prominence and hence "listen to that added air and detail!"
As others have mentioned, Harbeths are designed to have the grills on.They will have the intended frequency balance. I always preferred grills on sonically.
And aesthetically.
The Harbeths represent such wonderful, understated British design. Beautiful furniture in their own way. With the grills off it ruins this neat aesthetic. They look unfinished, more industrial, more "made in a shop."
But....audiophiles LOVE to see every inch of technology. "I paid for those drivers, I damned well wanna look at them!" ;-)
