I have coaxial 2x Radian 5215Be drivers that i want to put into some bass reflex cabinets. I thought the easiest solution for me would be to purchase some flat packs from diysoundgroup and see if they would work. Can anyone provide me with the port lengths i would need? And any suggestions on if this is a viable option? I want to use the Titan 615 Narrow flat pack for the build. Your input is appreciated.