Recommended box size is not even close to the same thing as the enclosure/sub alignment. Recommended box enclosure volume is for people who really have no clue what they're doing with enclosure design. Manufacturers do not all have the same idea for what the "recommended" alignment should be and most of the time, they just specify a range of sizes. Why? Because they actually know that people will like the sound of different alignments and there is no such thing as the "perfect" sealed enclosure.
You are making it seem like a couple fractions of a cubic foot will totally shift the alignment. Would you like him to plug in the specs for each driver and build a separate low Q, high Q, and butterworth alignment box for each sub? Putting a sub in a sealed box which is in the recc. range will give you a **** good idea of how it will sound in almost all comparable sealed box sizes. The OP is right when he says that most people will put a sealed 12 in a box around that size, its a good indication of real world results. I can see where you are coming from with ported boxes though, much less forgiving.
//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif
I guess then you're the guy who doesn't give a **** about details on paper and you cause planes to crash in the real world because you didn't want to get "too technical" about how much fuel you should put in the plane.
