Just got my Axioms today, a question

Got a probably dumb question.

1. W22's are ported and the W150 is not. Is that because W150 is for Voice and ... and the w22's handle more range of song and music?
2. How much clearance do the w22 ports need below and to the sides of the ports to be 100% effective as designed?

Just curious

Thanks

Jeff

Fronts/Wides:M22s in/on
Center:VP150/VP100 in/on
Hghts,SS,SR:QS8s
Sub:EP500
AVR:Onkyo 3008