Help with port length

[on1wheel01]

Well building a box with 1 6" aero port. Box is 30" wide 12" high 21" deep for 1 15" memphis m3 mojo 15. Looks to be 3.5 cubes before port. Im using a 6" precision flared tube and have no idea what length to make it. Help plz

[plugitin]

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[on1wheel01]

Ahh very nice hat off to u sir. Says for a tuning of 33 hz flared port length is 17. So pretty much a whole aero with 1" cut off right?