Grrr! Why does everyone say that. I get like 135d5-138dB with my SEALED, VOLFENHAGS! Mike, Muddy's right, you'll get extremely loud. BUT! Since L7's sound kind of crappy, and porting in my opinion makes a sub sound kind of "tinny" in comparison to sealed sub, I think the sealed would then make those subs sound deeper, and give them more of a bandwidth extension in the bass range.
That's just my opinion, I'm sure no one will agree.
Porting only sounds good though, when done right. And sometimes not at all, my friend has Kicker CompVR's in a ported box built by the installation business, and I think they were tuned to like 30-32Hz. My subs though Volfenhags owned in SQ and depth. Didn't get quite as loud, but were better in that way.
two decent subs, with decent power WILL get loud in a sealed box, but, they will get louder in ported b/c you are able to manipulate the subs suspension at certain frequencies.
bolted the sub to the box.......kinda easier to do on a W7 due to how you actually mount the sub and with the surround going over the mounting holes and what not!!
Unless your box is 2"-3" thick, using long screws is a waste. Most mdf boards used in sub boxes are only .75" and the sub itself is 1/4" thick. My box is however 1.5" thick cause of the MT sub. It weighs too much for .75".