Help With Tunning Port

[Bills]

I am going to start a box for 2 15" DC lvl 4 subs. I am going to be putting it into a '98 Chevey Blazer. My box dimensions are 38.5 wide by 18 high by 20 deep. The subs are going to be facing up and I want the port to fire at the hatch. I have to use this setup so i can still fit my golfclubs in the back. but I want this to have good sound quality yet get loud for db drag comps in my town. I want to do a square or rectangular port insted of areo ports this time because i think a slot port might work better. i have three areo ports and iknow how to tune them. first of. does anyone think i can get good sound and loudness with the areo ports? i want to tune them in the 30's. so any help with this would be much apreciated. i ain't great at spelling, never a strong subject in school haha.

thanks

Bills

[Bills]

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