Try 4.0 or 4.1 instead of 5.1... it's worth a shot

I just had something I wanted to run by everyone.I was tweaking some on my system and I noticed I got a much better soundstage from setting my center channel processor to "off". I'm not even using a subwoofer...not by choice though.I am now convinced with several trials that not only do I not need a center channel, it actually screws things up due to EQ problems.I have tried this on several set-ups and it was true every time.As silly as it seems I urge everyone to try it.I am using Thiel cs1.5's with h/k avr510 dv-47a dvd-a/sacd/dvd player and toshiba 65hdx82 rptv.
Johnwa- On a few occasions, the added center speaker would have been nice to punch up the speech that got a little buried in the FX mix. However, as long as your speakers are symmetrically positioned about the screen and they aren't too far apart, I don't use a center channel either. Then again, why would you wish to deprive the industry of additional sales of speakers and amplification and cables and .... Trust your own ears. Enjoy!
I agree with you to a certain extent. A lot of it has to do with how you have your system optimized i.e. for two channel or for HT. Speaker placement WILL be different if seeking optimum results for each mode. Type and radiation pattern of the speakers being used is also very important.

My findings are that if you have very good quality mains that can project a very solid center image, a center channel speaker interferes with things. If your speakers don't image quite as well and / or you have them spread out a bit further than optimum, a center channel can help things out IF properly chosen and set-up. Sean
I agree with Sean. I would like to add that if you have many listeners and therefore all can't be in the sweet spot, off axis listeners might enjoy the center channel. I also strongly believe that all chanells should be as similar as possible and equidistant from the sweet spot listening position.
I believe that my secret to my success lies in my Thiel's... they just have superb imaging.However, the clear fault here is that you really just can't sonically match ANY center channel to floorstanding speakers(or at least I have not heard this,as of yet). It also bugs me that one speaker costs MUCH more than 1/2 the price of it's pseudo-matched mains!!! It just don't add up.I can certainly see the need in some situations to have a center but luckily my room's dimentions and equipment just don't require one.I don't really agree with Sean about the differences between HT and 2 ch. setup... mine would be pretty much the same.