Sorry for bothering everyone. I'm looking to build the boxes, just hesitant on using new drivers and want to utilize existing 12" JBL Club which is missing information even on JBL website, like xmax, VAS, etc. The only info I found was this: General Specifications
Description
12" (300mm) car audio subwoofer
Power Handling
275W RMS, 1100W peak
Sensitivity (@ 2.83V)
93dB
Frequency Response
25Hz – 175Hz
Voice Coil Diameter
2" (50mm)
Impedance
2 or 4 ohms
Also, a note saying it has high excursion

which I'm thinking sarcastic on especially in car audio , excursion can vary greatly. It's probably about 6 to 8mm, I mean they're sitting in my truck now and I play them loud and hard. I think they should just be alin a Tuba instead, but I, I'm ignorant on this engineering business, so please chime in.
I mean, just because I can make cuts in wood making a speaker baffle doesn't mean I can stick a subwoofer in that hole and everything just go perfectly well. I know that they are ridgid and are a higher quality poly material. Thanks for reading .