Welcome back, Randey(I remembered). Inserting a resistor in series with the tweeter reduces its output uniformly over its entire operating range, unlike the effect of a tone control.I'd be hesitant to do that, and not being an audiophile, would have no hesitancy in using the tone controls or even a graphic equalizer to help some of the lousy recording jobs sound less appalling.

Enjoy the music, not the equipment.