Help with a 6th order enclosure for 18" Atomic APX D2

[detroitdb]

Long time no post guys, Hopefully someone can help me tune this 6th order. My gross dimensions are (rear chamber) 6.58 cuft and (front chamber) is 4.17 cuft. These dims do not include woofer displacement. I would like to use 6" aeros for porting if possible. Now what do I tune the rear chamber @ and what do I tune my front chamber to? Please help me. thank you in advance

[detroitdb]

^{is the ratio way off just wondering?}

[Sanitarium]

if this is a series tuned 6th order, then yes your ratios are hugely off.

[detroitdb]

how about 4th order?

[detroitdb]

^{any input guys,}