Speakers: same brand?

The two fronts and center should be the same brand.  It's much less important on the sides and rear.  I'd get the Tekton center.

It is very important the center is the same as left and right. Most dialog on HT comes from center (85% of sound) it needs the same character as others. 
 

Certainly does help to have all the same. But it isn’t as important.

Thanks guys. That’s what I was thinking that the voicing of the fronts and center should be the same. An excuse to get more gear!

Not a problem.

I have ESL front and ribbon center. They integrate well.

it must be the same or the sound quality will suffer badly

Some people like to mix up all different kinds of speakers and equipment and that's what it usually sounds like.

The center speaker is the center of an HT system, if you forgo the center for any reason (you don’t like the clutter) the two mains have to pick up the center slack.

I built a pair of OB lattice towers with 6 neo 8 planar each. They are only 7" wide each. They are also 95-97% efficient. THAT is what you want to pay attention to. The higher the sensitivity on the center channel or the phantom (if you only use mains) is the key to good HT vocals. If face to face voices and whispering is a WEAK link and background noise like cars, radios, that kind of stuff if BOOMING away, guess what? The people that designed the center speaker weren’t thinking either. AT ALL?

The Lattice towers play from 150hz to 20k. I use bass columns. I place one lattice tower on either side of one (8" driver x 6) bass column. The BC are 94% efficient.

I’ll say this without a doubt. It’s the best center speaker I’ve ever heard. and will hit 120db. 25hz-25KHZ. You can hear people lick their lips.

I built 3 of those pairs before BG started thinking their drivers were made of platinum instead of aluminum and a planar film. 4-6 times the cost now.

I’ve seen a few 30-100K center speakers.. Mine may not have been as pretty but they sure worked well. I used Apatong 3/4" x 3/4" for the Lattice.

Just look up the specs on your current speakers and make sure what ever you use is a higher sensitivity. If the guy uses all the same drivers throughout his builds and the center speaker, that could be an issue for GREAT HT, which is rare anyways.

I use stereo. period. I don’t watch TV. The Bass column I used for the center I double up on. and add GR servo subs. 

Center speaker is very important in HT.  It provides all the voices and center of action, and the sides and rears are just for sound effects mostly.