couple port questions for a ns v.1 12

[06 Scion xB 0]

Ok I have a saz1500d and a ns v.1 12 inch sub. Box is currently 1.45 cubes after sub displacement and current port. Port is a single 4inch aeroport which is as long as can be without touching sub, don't remember actual length, however, I do know I punched it into the port calculator on 12volt.com and it was 38.3 hz roughly. I want to bring it down to about 32-34hz. My question is would it make a big difference if I used a 3inch port with my flared ends of my 4inch aeroport? Or should I just go with two 2 inch aeroports. I would like to use what I have currently but wanted some answers to this question.

Second question, should I just keep what I have since its a higher freq and just lean more towards spl or am I actually hurting my spl because its higher then the normal 32 hz range?

I want the best of both worlds and with the rest of my system and my awesome products from Sundown Audio, I should be able to be pretty good at both. If it helps any the rest of my system consists of old school Boston Acoustics Pro series components up front, running off an old school USAmps 4 channel. Big 3 done and zero guage wire everywhere. Lastly, a second battery which is a kinetik. Head unit is a Pioneer Premier. So like I said all of this should be able to give me pretty good sound quality and spl.

Any help is greatly appreciated,

06 Scion xB

[Duran 387]

Higher tuning will yield higher numbers on a meter. I would use a flared 6" port if I were you