Pioneer’s TS-SW2541D is going where few subwoofers have gone before: into shallow spaces. The woofer requires a depth of just 3-inches to produce full-sounding bass.
That means that it doesn’t require a giant enclosure to sound right. It also means that it can be situated in spaces previously unavailable to subs.
So, considering its $180 price tag, expect to see cars completely filled with these things in the near future. It’ll happen.