I downloded Fidelizer onto my music server this morning. It is a program that optimises your computer for audio.
So far I am pretty impressed with it. My background seems quieter and "blacker".
I went with the Audiophile setting, there are two other settings, Pro and Extreme. I'm usually a extreme kind of guy, but I thought that I would work my way into this one.
From what I understand this program changes the priorities of everything running in the background to optimise music playback. I'm still using JRiver 17 as my player but it sure sounds better. Best of all, it is free.
I'd say give it a try if you are using a PC as a source.
http://www.windowsxlive.net/downloading-fidelizer

I don't think this will be very popular in Miami because the name evokes Cuban Dictator Fidel Castro.

I can now confirm the positive results obtained from Fidelizer, in my case.  I had some minor (but nagging) occasional latency issues while streaming, not anymore!  So, at least from a streaming efficiency view, it really works.  

I'm inclined to also recognize some sound improvement with it, but since my system is going through a lot of break-in and layout re-settings, I can't tell whether there's cause-and-effect linking Fidelizer to the recent sound quality improvements.