if they're a bit bright, why not turn the treble down since it's at 30%? Also though, if that seems to degrade from the midrange characteristics... try this simple trick. Put a piece of cloth in front of the tweeter behind the grill. It'll be hidden from the public, and it'll help dampen down the brightness of the tweeter. Experiment with different fabrics... it's a cheap trick, but it works wonders sometimes.
