http://www.jblproservice.com/pdf/Thi...Parameters.pdf
Here you can see that the XMax of the 2214H is only 6.6 millimeters. Not a huge figure really, especially compared to a typical subwoofer. Nothing is working incorrectly, you are simply bottoming out the woofer. The voice coil reaches the bottom of the voice coil gap and makes contact with the pole piece (part of the magnet). This is what causes the POP sound.
The 2214H woofer can handle quite a bit of power, and put out a lot of bass, but not at frequencies significantly below the tuning frequency of the cabinet. Below that point, output drops off very quickly and the woofer is able to move too freely, which is why it's exceeding XMax (actually exceeding "XMech" once it makes contact with the pole piece). The L100T and XPL200 are ported designs, where the resistance of the air movement through the port damps the movement of the cone, but not so much when below the tuning frequency.
It's just a matter of what it was designed to do. Specs of both the XPL200 and L100T show response down to 35Hz at -6dB. 35Hz is not an amazingly low figure (compared to something like a quality subwoofer) and output is already down a bit (-6dB) by that point anyway. Those aren't bad numbers for a speaker really. *Most* music does not even contain bass at 35Hz or below, but obviously some does.
The real solution here, if you are playing music with extremely low-frequency bass and doing so at at loud levels, is to integrate a quality subwoofer into your system. Do this using either an external crossover of some sort or use the crossover that is built-in to the subwoofer (usually by running your speakers through the high-level input/outputs on the subwoofer) to re-direct the problem frequencies
away from your speakers to the subwoofer instead.
Understand that integrating a subwoofer into your system does NOT equate to giving up on the goal of significant bass output from your XPL200 speakers. It doesn't have to be like someone who runs small bookshelf speakers with a subwoofer and a crossover set to 80-120hz. With speakers like the XPL200 you can get away with a much lower subwoofer crossover frequency. Perhaps something around 40Hz give or take. There is still a LOT of bass above 40Hz, and once you've eliminated the possibility of problematic ultra-low frequency content bottoming out the woofers, you can then get away with really pushing the XPL200s hard with bass content that they
can handle. Anything lower will be handled by your subwoofer exclusively, but that should be limited to only
very low frequencies at that point.
I have L100Ts. I power them with 700wpc and I push them VERY hard, but I also run two subwoofers. That gives me the freedom to push the 2214H woofers in my L100Ts to the limits of what they
can do rather than forcing them to do something they can't.