I would absolutely recommend Infinity Reference REF1200s they require less than a cubic foot of air space. I am very impressed with these subs, the box I have them mounted in is 4.5" wide. They bump very hard I love them. I have them set at 4 ohms on a 250 watt rms amp. They do exactly what I was hoping for. Great value great product. I was skeptical of slim subs in general but being that I have a crew cab Silverado I had limited space to work with. The mirror actually vibrates and I can feel the bass hit. More than I expected for sure.