center channel placement ?

I think dual over under center channels will cause more problems than solve. In a real theater the speaker is behind the screen. Can't really do that with a DLP TV. I prefer setting the center just below the screen. The reason being that most dialog is sent to this speaker. Watch most material and the mouths of the people on screen are closer to the bottom. Voices from the sky are not very convincing. My rules for placement start at 24"-36" off the floor bottom edge of screen. Center speaker as close to the bottom edge of screen as possible. Higher up has less floor interaction which will muffle the sound. L&R speakers just to the side of the screen near the bottom 1/3 of the screen. This gives you decent panning left to right without sound jumping up and down vertically. If you have floor standers you can try pulling them out a bit to form a nice arc equidistant to your chair.

You can place a speaker on it's side. A 2-way won't make much difference. The 3-way might be less convincing because the drivers are spaced out more. You might hear more treble to the left and bass to the right for example. Vertical placement might be best. Tweeter just under the screen.

As for home made subs, you can spend a lot of time and money and not get good results. Also pretty much worthless resale value. The velodyne DD series is pretty impressive. Try to find a dealer that can show you the set up process. If you really must, I would find a kit or plans on-line. Maybe Madisound has one? In the end, you probably won't save money.

thanks for the info!!!

I was debating on buying 2 infinity kappa centers (use the same tweeters I use & a 5.25in driver) but I am concerned they might not have enough mid.... Those would be cheaper & easier to position then the kappa 5.1's but the 5.1's would defiantly give better mid/midbass.

So you think top/bottom is bad...... I was hopeing that if they are top/bottom they would image kinda like a L & R speaker does. Hopefully image in the middle of the screen & be angled up for the bottom one & down for the top speaker. If I do the kappa centers I could just as easily put them next to each other either under or above the TV

Back in the early 90's the AV company I worked for did a couple of these over/under center channels. We had the same idea. Image vertically. The problem is that unless you are in the perfect spot there is going to be time variance between the two. Most likely the distance to the lower speaker will be closer than the upper speaker. This is bad for imaging. Later we became a Meridian dealer. They have a cool feature called tilt on their center speakers. It psyhco acoustically raises the image in increments of 1,2 and 3 feet. It was easy to up sell a customer to a digital meridian system and use the center channel set under a 100" screen with the +3 tilt. I would not recommend mixing speakers though. Matching brands and drivers will give you the best results. You can experiment with the two Kappa speakers or use one for rear in a 6.1 configuration. The center speaker is 50% of the soundtrack, so I believe your concern for size is valid. Another option is to drop the center and run phantom. If your speakers image really well, you may prefer that. There are some threads about this in the forums. I made comments on them years ago.