Just wanted to point out how important it is to have your monitors at the right level. The tweeters should be in line with your ears not on the desk. High Frequencies are Directional hence the reason for this.
Not everyone's average desk like my own has supports or blocks to raise the tweeter to the right height.
So what I did was stack 16 DVD/ game boxes on top of each other and faced them in a vertical line. Perhaps this seems like a common sense idea however i have seen pictures of this being over looked, and it does make a difference.
Also make sure that the monitors face in this position Google Image Result for http://www.ecoustics.com/electronics/messages/34579/705939.jpg
So to sum up hopefully you will find this tip simple and helpful to provide a better listening experience. The amount of dvds vary obviously because not every desk is the same but just so that the tweeter is at the same height as your ear is the important key point.
Anyway all the best