> Is the recommended closure ALWAYS the optimal box to build for subs? I
> have a normal size 3/4"MDF generic ported sub box. If I build a new
> box to the exact dimensions that are in the manual my subs came with,
> will I notice?
The answer is a definite "MAYBE".
Depends on a lot of factors, the difference in volume between your "generic" box
and a "proper" box being the main one, and how the design of that particular sub
reacts to those differences. Shape of the box could have a small but noticeable
effect. Position in the car may make any differences unnoticeable anyway.