Wow. I don't know what I find more frustrating here: the totally off-base implications or the blatant baiting of an Aperion employee over what appears was well dealt information with honest intentions.
Based on the photos provided by applicable forum participants, I'm left to gather that few of you build your own subs. Maybe you do, I don't know, but you can't tell from your comments.
A concession: The use of the terms "slow" or "fast" are horribly inaccurate and, indeed, misleading. To continue using them perpetuates the publics misunderstanding of popular "audio adjectives" that attempt ( albeit poorly) to explain in words the things that we hear since we rarely share a frame of reference. Also, it is a myth that an 8" driver is more capable of producing a 200hz wave than is a 12" driver. The size of the cone isn't really a part of this equation whereas the motor structure and moving mass ARE.
That said, those in the know know that building a speaker or a subwoofer is a calculated set of trade-offs. If you want to build a sub for the common man, you build it such that you maximize the inherrant values of a given driver, amp and enclosure size. Those who want a 12" sub tend to want a big bass sound with substantial SPLs in the lower frequency range. With a popular ported design, you can naturally achieve these results with a solid amp, well spec'd driver, highly rigid enclosure and properly tuned port. For use below 70 or 80 hz, this is great. However, you're going to find that this design doesn't lend itself to production of a 100 or 150hz wave nearly as efficiently and, if combined with bookshelf or satellite speakers, may leave you feeling your mid-bass region is a little anemic.
If you have just such an arrangement AND you're sensitive enough to this that you just can't live with that little hole (and let's face it... these people usually know who they are and what they need already) , then you're the sort of person that is going to spend the money necessary to get a 12" sealed, sub with exceptionally high powered amp. Maybe even a "servo-controller chip" Ooooooh. And good on ya.
None of this has anything to do with using multiple subs. Two 8"s, two 12"s an 8" and a 12"... no matter the combination, you will be generating extremely long wavelenghths from two different areas in the room which WILL give you a more even response throughout the room (note: it won't help with standing waves- you're stuck with those unless you are ready for some room treatments) What you will accomplish is a more complex wave pattern and a better overall dispersion of wavelenghts longer than 12 feet.
Word up.
