Freek Audio

Hey all, Thanks for the great work and build shots of everyone here in this thread. Been great to read through. We're looking to build 4 x of these to run with a pair of PM90's (and perhaps some Martin Audio 213 Mk3's after that). We have 4 x B&C 18SW115's that we were hoping to load the cabinets with. We had a couple questions: Could anyone provide any commentary / sims on how the 18SW115 would run in this cabinet? We'd like to cut an adaptor plate for the 18's - to keep the option open to install some 21's at some point in the future. Will the adaptor plate impact the sound of the cabinet in meaningful way?