Building a big setup like that is NOT easy at all. Don't make it sound like it is.
Money and equipment does not = loud, which has been proven by a LOT of people who pay for big installs. It still takes a lot of testing and tuning to even think about pulling those kinds of numbers, even with "gobs" of equipment.
Lots of people build big setups and experience so many problems that it never works correctly. The only way to do what these guys do IS to have a big setup. Somebody might be able to do it with less, but they'll have to push their equipment to the max to do it.
I give props when they are due, and these big bassracers deserve it.