Just got new speakers (Acoustic Researc 2062) and was planning on putting them in a book shelf. 2 questions: 1) The manual says the front of these speakers should be flush with the front of the bookshelf. Why is this? Do I have to do it? 2) These speakers have a port on the back (for the woofer I assume). How much space should I give between the back of the speaker and the back of the book shelf? I estmimated placing the speaker 1/2 the radius of the port away from the wall will provide enough room for air movement by comparing the surface area of a circle--the port--to that of a cylinder wall. However, I'm not sure how appropriate this is since it does not take account of acoustics.