Hey all, I'm pondering having some assinine cabinets drawn up with 21" subwoofers. As a bit of background, I do mostly sludgy drone stuff (think Jucifer, Dark Castle, et cetera) and really wanna reach for that deep earthquake rumble. I'm currently going to be using a Mesa Boogie Strategy 500, though I may end up with a couple old Sunn solid state bass heads, or Acoustic 370s when the dust settles. I'm getting a fantastic deal on the cabs, and I'm really excited... but ignorant, and well ready to admit this. I know enough to know WHY I want the big speakers, and not the least of which is the audacious visual and nausea inducing lows. I'm reaching out to the more educated, in hopes of being pointed in the right direction to take advantage of this great opportunity . Things I'm confused about, in essence: How much difference does the size of the magnet have? I'm looking at a couple options, but my lead is this'n right here, because of price and a nice frequency response. Any comments? Experiences? Reservations? Cabinet recommendations for dimensions? I should note that I'm on a budget, but I'm willing to wait in order to not have crap. Also, wait and size aren't really issues for me. Thanks a ton, guys!