Originally Posted by William They don't.
They don't even sound as good as "crap". Your Polk's are as good or better. Also speaker sound is much more subjective than all other components.
So either it's subjective and therefore your view doesn't matter and your claims about sound quality are irrelevant, or it's objective and your view matters and is relevant. I don't mean to pick at nits; this just smacks of one of those "blind hatred" kind of anti-Bose rants. It can't be both ways.
I agree with everything that Kal said; regarding some tutorials or guides, try this perhaps:http://www.dolby.com/us/en/consumer/...ide/index.html
There's also some acoustics info available:http://www.realtraps.com/video_setup.htm
Regarding new speakers, I agree with Kal as well. Regarding the question over Bose speakers - they aren't terrible, but they're still subject to the laws of physics. In other words, they're very small speakers - and like any other "very small speakers" they will have limitations in terms of frequency extension and output. Depending on the environment and the listener's personal taste, they can be quite suitable, but it's not generally a direction that I'd like to advise people in. Here's basically why:
The Polk speakers you already have fit into that "very small speakers" category as well; the Bose system will not overcome many of the limitations of that paradigm. Sure, it may be a slight improvement, but if you transitioned towards something different (say, Polk Monitor series bookshelves), you would "change the game" so to speak (you would have mains or satellites able to dig lower than around 200hz, for example).
I'm not saying they would sound exactly the same, just that you're not overcoming any of the problems with the "very small speakers" scenario.
If you're going to buy new equipment, I would look at the subwoofer and LCR first; get a subwoofer that can hit harder and dig lower, and an LCR setup that can do the same. Those Polk speakers are probably perfectly fine as your surrounds.