There was a test in an acoustic lab, when I studied, so this was long ago. There was a set of hifi stuff, one CD, and three sets of speaker grilles: black, brown, and white. The listeners had a short break between "changing speakers", while only the grilles were changed.
Guess what? White was slightly aggressive, brown pretty dull, and black most balanced.
Aluminium! Shiny aluminium! Therefore Hartke has to be aggressive, and what were their words in the advertisements? Transient attack!
(The question remains, what does it mean?)