Does that diameter away from any walls and woofer mean like all ddirections...like could it be only a couple inches away from a side wall as long as the opening is more than 4 away from the back wall?

 

Ideal is a diameter away from everything. This is not always practical but it is most important to be at least half a diameter from the back wall, a full diameter is better.

 

I just got my port pieces and other stuff yesterday so i started on my ported box the site that i ordered from had 90's so i got one of those so i could redesign my box to a more desirable shape but i was wondering how much does the 90 add to port length? do you measure from the end to center? if so its 2 7/8" so am i right in thinking that it will add 5 3/4"?