Now a while back I paid attention to this in order to find how the speaker's response would work with the cabin gain. I found out that depending second and third harmonic distortions I either liked it(clean) or I didn't(muddy). A lot of that had to do with the back wave from the subs which directly related to their position in my trunk.
Anyways, here's a post that basically says go to hellMostly because the Qtc of a speaker can change as much as 10% just because of temperatures or other factors. Matter of fact, it's changing as the speaker plays.
DIYMA.com - View Single Post - Q alignment for sealed subs - which do you prefer?