Guys, I wouldn't worry about the sound system. As Scott has said in past interviews I have listened to, he used a sub in a bandpass box.
He used a technique that gained a lot of popularity in the "boomin system" days of the 90's and 00's. A properly sized bandpass box will make a cheap $12 Partsdirect sub coupled with a half-way decent amp blast out anything else in your game room.
Pins don't sound as good as the TNA proto did because they use cheap under-powered amps, and a "Woofer" in a free air setup. The highs are rarely any good, nor crossed over correctly, if at all. None of this is expensive to put into a game, but always seems to be an after though from pinball designers.