Optimum speaker placement

I am about to go to war with my wife and set up the 2ch/5.1ch in the den as optimally as possible. Before I bring it to her (and the negotiations begin), I need to know what constitutes the "ideal" placement arrangement. I know that mathmatical formulas have been around for years, however I haven't any clue what they are. Additionally, room treatments will play a significant role. Does anyone know of any printed material (or web-based) that I can review? Thanks in advance for your advice. - Ken
There are some computer programs, like Visual Ears, Cara, or programs integrated in speaker building programs like SoundEasy 3.20(that I own), where You can model Your room and speaker placement, and get a lot of information, before placing the speakers out. I have seen programs for two-ch. stereo, only,but the programs can probably help You although. Some good book on acustics, is also recommended, and the sites mentioned above.
It depends a whole lot on your speakers - some really need breathing room, others can get by with less. It probably also depends on how precise you want to be - there are probably enough other compromises going on that a foot one way or the other isn't going to be that big a deal, unless it's the only foot between the speaker and, say, the back wall. If the speakers are rear ported, you need more room behind them than if they're front ported or non-ported. I don't imagine any speaker likes being closer than about 3 feet from a side wall.
Check out Cardas Cable's site at Cardas.com for good math and insight on speaker placement.
try the link listed below. Just a bit down the page, there are several different methods for doing speaker placement. As mentioned, this includes Cardas, Wilson, Audio Physics, etc... All of these pertain to 2 channel though, so you'll have to adapt to your individual room and installation. Keep in mind that no "formula" can take into account each rooms various furnishings, acoustics and your speakers dispersion pattern. Trial and error still works best, but at least reading the various ideas will give you a baseline as to what your working with. Sean > http://www.audioasylum.com/audio/faq.html
This is the info. I was looking for! Thank to all of you for your help. Ken