I am going to have to make my 2 Pis from 3/4" material instead of 5/8" and understand adjusting dimensions +1/4" in all directions to maintain the proper cabinet volume. Regarding the port length, do I need to maintain the overall 1-7/8" port length or do I add 1/8" to the port length to maintain the same port length inside the box?Also, am I correct in thinking the edge of the port cutout should begin 2" from the bottom and 2" from the edge of the assembled speaker cabinet face? Thanks