may be a stupid question but just curious to know what difference would it make if a sub is turned around like if the magnet is in the box or out of the box
like taylor said, there are those who argue that the motor structure causes a loss of a bit of spl. but others say that the waves just diffuse around it due to size. so, regardless, no difference noticable to the ear. i had the same dispute and finally understand that it's "the same sandwich." that's why i'm going inverted myself in my current install.
yup like glass said if you have a sub that has a displacememt of .25cu/ft and it requires 2.5 cu/ft for optimal sound. If you build a box 2.75 cu/ft and drop the sub in normally you will have your 2.5 cu/ft after displacememt but if you mount it backwards you will have 2.75 where your sub requires 2.5 cu/ft. it prob wont make a huge difference unless it is ported but if it is sealed .25 cu/ft really doesnt make that much of a audible difference at all if any.