Check out this site http://www.mach5audio.com. The shiping is a little expensive but the quality is excellent. I would proably start with two speakers and then if you are not happy you could install the others later. From my experience just about any woofer/subwoofer will work descent it depends on what your application is going to be.

HT-EXT

maybe seal the brahma's or put them into a tl or a ported box. but no way a hw. too little port area.
the mach5 idea is great.
now, about pa woofers : i've recently been o a friend's house and listened to his system. 1 15 in a 4th order bandpass. i was thinking where are the lows ? it's a 15 dammit.

[quote author=Wreckinthehouse  link=1166651855/0#4 date=1167333409]have you ever heard one horn loaded? Now, I'm not talking about exaderated bass, I'm talking about flat bass response the way it is intended. As far as going low the HW will do it regardless of the driver being used, so his box must not have been right. My horns wont go as low as a HT sub, but WILL spank a HT sub in every ther aspect. Sensitivity, output and the most realistic live sound your gonna get without a band. Horns rule without a doubt. My autotuba will outplay both of my db 10's with a cheap $35 woofer. I'm not in anyway disrespecting Steve's designs, as I have 4-dual 15" loaded HW's and 2- Kove audio loaded db10's, but the horns are so much more efficient and sound so much better to me. There must be a lot to this horn theory or there would be no Imperial. [/quote]
i haven't heard a horn. yet  :-*
in the end it's all about the application. you don't need sub 40hz in live events but you need them in a ht setup. for IB it would be very sad to use a pa woofer with 3mm x-max. and horns are a little impractical in a smallish room.
light cones vs heavy cones ? application dependent IMHO.