Well its all about preference. Sealed is definitely the way to go for sq. No ported box will get the same kind of punchy tight bass you can get out of an optimum sealed enclosure. However i like a combination of SQ and SPL so I run custom built ported enclosures designed for the subs i run and the car i run them in. Ive gotten pretty lucky since the owner of the audio shop i buy from owns a Grand Prix and has built many boxes and designs for his so he knows the dynamics of my car quite well. Plus hes interested in my box designs since most of the ones I come up with are things he hasn't seen before. For SPL the guys i'm having build my box hold a few world championships in DB-drags. They also have won quite a few SQ competitions in Missouri so i think the box they build will be just fine for my taste.
Check my build logs! After doing it, I'm sure it could be done with cut outs too
