I bought an apsm 1300 and a 4 gauge wiring kit. I am building a ported box tuned to 27 hrtz. And putting in an obsidian 15" d4. I'm am deciding between this set up or 2 sa 15's. On the same 4 gauge wiring and amp. This is if the subs will fit in my 09 civic lx. I'm planning to take out the spare tire. So the main question here is if I I decide to go with the sa's for around another $200 would the results be worth it. Idk if I have the air space for the sa's to function properly. Thanks. What should I tune the sa 15's to?