I would like to build the LLT. I will be using the Ultimax 15" DVC. Also have (4) 4" x 18" flared ports to use if necessary. The enclosure will be behind the couch so it will have to be narrow 18"/20" but up to 30/32" tall and 50/60" long. Recommendations for speaker/port location would be helpful. Also have 4" elbows (90 degree) if needed. Maybe fire the sub down and ports forward but the use of the the elbows would probably be needed with the limited room. I have built other subs but not one of this size. Any help with this matter would be greatly appreciated.