Best Big Sub? or duals?

Unfortunately this site http://www.servodrive.com/ is down. ServoDrive uses belt driven motors to actuate their cones. These are not self powered or crossed over and they require much less power. Ask around, these are the loudest cabinets by a large margin.

Meyer Sound has a nice selection of bins and powered units. There stuff sounds much better than their specs would have you believe.

Bag End ELF systems are typically in sealed enclosures and they also require less power and come in many sizes. Their designs may seem dated but they go lower than most anything out there, they simply work. There were two 18" cabinets, processor, and an amplifier for sale here for $1200.

12K for a sub is a joke. Do your homework. Whatever you select use a Velodyne SMS-1 then let any HT room correction take it from there.

you may be interested in something like this

12K for a sub is a joke. Do your homework

I agree for pure HT applications (just movies) it is a waste and a joke.

HOwever, it is not a joke if you want THD less than 1% and excellent transient response (say a Q of 0.5 or less) and capability to 120 db SPL or so in a large room. (As opposed to a "bass bin")

Large high quality TC Sounds drivers start around $1000 and shipping one of those 80 LB babies (yes that is JUST the driver) will cost you an arm and a leg too. (I am not sure you can even find these drivers in the DIY market anymore). Then you need a cabinet and a big amplifier. Even if you build it yourself and buy the amp you are probably looking at around a minimum $4K in parts.

See interesting pics from HT Shack. What a beauty!

Take a look at a new sub from Hsu. It is a sealed sub with a 15" driver and is also wireless. I have been reading great things about it over at AVsforum on their sub forum. A great place to read up on whats out there.