My old systems were
4 Olympic warrior 10" in a .808 Q box (tuned really really low usually good for overall sound quality) but those were special small enclosure subs and i was able to tune them to 47 Hz (great for rap listerns)
My next box was a Band pass box tuned for spl (overall Q ratio of 1.2 ish) that was also tuned to 47 Hhz, It took 1st place in the area 51 car comp in carson (like 5 or 7 years ago) hitting 138 DBs in a honda prelude si
then i went with my new system and setup a box to be tuned to 35 Hz with a low Q and hated it big time. ( i listen to less rap then before) but that's just too low for most of my music, i recaculated and decided to take out .8 cubic feet of air, i did that by glueing blocks of wood into my box. Now it sounds much better, but the box alone weights like 90 lbs... (with out the sub) i hate the orientation too. so i'm just waiting till i decide to 'do it right'
if you want some help figuring out response curves, tuning Fs, and what not , lmk i'll need to find some specs on the speaker you are going to by, and what type of music you like, what type of bass you like.