Using an underdamped 2nd order hi pass filter would be a much better approach to EQing a ported box than would an LT.It has fewer components that would need varying to change tuning and it protects the driver below Fb.
Assuming 3/4" MDF is used,it looks like the 2 opposing side panels that B1 attaches to are both 20"x15.5" and the side panels that B2 attach to are both 20"x14". The top panel is 15.5"x15.5" as is the outer bottom trim panel. The recessed bottom panel that the driver mounts to is 14" x14" and needs an 11 3/16" diameter circle cut for the driver.
Here is the link. http://www.rythmikaudio.com/download..._DIY_plans.pdf The plans look fairly straight forward,what section are you struggling with?Also if you have questions Im sure the good folks at Rythmic would answer them for you.
Hi Freak,Im not sure if this will be of much help but here are a couple of pics of one way to build and brace a box.I used dados that I cut on a table saw.It makes for easy assemble if you build your own box.Ofcourse you wouldn't be able to dado the ready made PE box .
You may get more specific replies on the Rythmic design if you can post a link to actual plans.
Here are some links that may be of help to you. http://www.hometheatershack.com/foru...-traps-eq.html