You'll be glad to know it's even better in the real world.
There are a lot of really good subs out there, including some SVS, Velodyne, and Hsu, which are great bang for the buck. Then there are some premium subs like Bag End, Revel, etc., that give a lot of bang and demand a lot of bucks.
At $2000 retail (a lot less on the street) unamplified, the S1S-EX is a huge bargain in my book. The 2242HPL is everything I've longed for in a sub: unbelievably powerful, very well controlled, amazingly fast and articulate, and just plain
stoopid in its range.
I was in the ToddAO mixing suites on Sunday where they had JBL dual 15" fronts with horns, supported by Bag End 18" subs. I would throw a comparable number of S1S-EXs against them any day. I walked out on top of the world knowing I hadn't spent that kind of coin on really good subs like the Bag Ends when the JBLs do more for less.
I have not heard a
4645C with the 2242H in it, so I can't comment from experience. However, I don't know if JBL is making a distinction by deliberately calling one driver a 2242HPL and the other a 2242H. :dont-know
I can say that with a smaller enclosure than a 4645C and three ports, the S1S-EX does not chuff at any volume and it pushes out a heck of a lot of air.