Duran

With 15 cubes net I'd opt for the three 15's.

Much better port area, should do very well

Can you afford any more port area?

The Idaho guy is a rep.

At mid 150's your body is being physically raped, it is painful.

DJ Slow 'N Throw did a remix of that song, its very good.

Because xmax does not necessarily mean SPL...lol

If sound quality is the goal I'd much rather have a 21" cone than a 12" cone.

Amps have gain knobs for a reason.

Awesome boobs.

A single Q could rattle your teeth if you designed it to do so. It's all in the enclosure you put it in

That is incredible...

A 12" Q sounds incredible, both ported and sealed, it would likely be enough output for you considering you want SQ over SPL.

To answer your port area question: http://www.carstereo.com/help/Articles.cfm?id=31

More port area while retaining the same tuning would help considerably.

The N2 has less motor force, thus a more flat response, it sounds better daily. The N3 has a much stronger motor, it will peak hard right around tuning. The Supergauss response is closer to the N2, but with more output.

I understand, but like I said, what kind of space do you have to work with?

I have an N3, and it sounds just fine to me. Sound quality is objective, to Richard Clark I'm sure my N3 sounds like crap. The Supergauss woofer would excel in a daily scenario though. If weight or space is a problem, the N3 would win. Do you see what I'm getting at Opry? You asking which woofer is best does not help get your question answered.

Better for what?

Dracula?

Bigot's don't belong in office, religion doesn't either. John Adams quoted once that the United States was not founded upon the ideals of religion, the interpretation of the Constitution has become very skewed

I would imagine it is, I use a new Nano with mine, its new enough that it won't change, but it plays.

Twice as loud means a 3 decibel increase in SPL.

It would be a big upgrade with the BTL 18".

I'm 99% positive it won't be as loud. You lose a huge amount of cone area, and don't gain enough motor force to make up for it. You can always recone the BTL to an 18".