I was just going to respond about the various options now beginning to sound like there is no reliable option ... only what various users have experienced and were happy with.
This is just the issue. The gear I recommended is solely based on what I've heard and what I believe might meet your needs in terms of tone. However, the MD rep made a valid point. Some home audio gear doesn't play well with instruments. Your best bet might be to take your speakers down to a Guitar Center or some other pro audio shop and see of they'll facilitate some comparisons with their monitors. I have yet to encounter a powered studio monitor that doesn't have an irritating top end, but they could exist somewhere.
In the meantime, you might try placing a piece of tissue paper in front of the tweeters of your current monitors. Not on the tweeter, but stretched across the opening in the baffle. You might be surprised by the results.
Good luck.