2.1 vs 3.1?

In my opinion....NO. Most of today's wimpy centers are easily drowned out by any decent pair of tower speakers. If you are not going to run 5.1 using four small satellites/bookshelf speakers and a center you are problably better of just using 2.0 stereo for your movies and music.

It depends IMO. If we are talking a set of really nice towers paired with a center with 4.5" speakers then I agree that it wont sound good at all. However for myself I am using two Infinity Primus 162's as my fronts and plan to add the PC350 as its quite a nice massive center when I can to my office setup.

I dont notice a huge lack of vocals when watching movies from my computer through my Denon 1610, but there is a discernable difference between my office setup and my bedroom (which has a center). The bedroom is a simple 3 channel setup (Polk R50's as fronts and CS1 as center) and the center does make a difference, even if its only being used mostly for HDTV and not movies.

What set of towers are you looking at, what center, and what size room are we talking? These pieces of info will help us give you better info. A image of your layout would be most helpful as well.

if you were a heavy movie watcher, than the 3.1 would have definite advantages. For normal TV, which is stereo anyway, a 2.1 setup will do fine.

I have had a stereo system on a secondary TV setup for many years and never had a problem with dialog, but it is a smaller room and the stereo soundstage works fine. We tried a similar system on my sister's setup in her open living room and the addition of the center channel was a huge improvement.

Experiment....start with the 2.1 setup and IF there is a problem with voices and dialog, then try the extra speaker.

Hmm. I've owned over 10 centers within the last two years along with various tower speaker setups. And none of the conventional centers with twin 5"-6" woofers paired with a 1" dome tweeter center made any difference in my setups. The only centers I've ever heard that actually did make a discernable difference were two custom centers I built. One with with a 1" dome tweeter, 5" mid, and two 10" woofers. The second has a 3" horn tweeter, 6" mid, and two 12"s. The second center is by far my favorite and it can easily fill up an medium sized room on it's own at moderate volume.

Most of these smaller centers just don't get it done in my opinion. But to each his own.

Anyway you look at it you will want a sub for your layout IMO. Your price per speaker is more than enough to get you some good options, but take your time to go listen to everything. I personally would suggest getting a center at a later date if for nothing else than for movies. You can run everything without one and my brother in law does and it doesnt sound bad. I myself am just OCD about having a center.

I would start with 2.1 and see how you like it. If you feel the need to buy a center just make sure you decide within the return period if it helps your system at all and if not return it.

I will also mention that room accoustics play a HUGE role in how speakers sound. You need to kinda layout your room so that your not sitting in a null zone. In my last apartment two of the seats were in one simply due to the layout. In my new place they are all positioned properly and it does make a difference.

The subwoofer will be needed.

Ron