For a little while back in high school I
was an ignorant bass-head kid.
I am unfamiliar with SI Mag, but I certainly know and understand JL Audio products. Lovely.
We're all happy to help around here.
If you are still shopping for subs, my only real advice would be to take a look at SVS's offerings too. Yes, yes, the EP500 is a monster sub, no question. But HSU and SVS make some really sweet subs as well at a slightly lower price point. I love my SVS PCI+ 20-39. It's musical and tight, but can literally break my house when needed. And I dig the water-heater look.
"What's that?" That's my sub.