I started setting up to build a new system. I was lucky to be able to purchase a pair of 476Mg's and was gifted a pair of 2216Nd's by my friend 4313B. I am going to use my favorite waveguide PTH1010. It has certain advantages similar to the 2344 because it is very short and has a rapid flare compared to the other PT Waveguides and is 100x100 which works very well in my room. I started taking some preliminary measurements on a temporary baffle of the raw drivers on the PTH1010.
It actually measures very well and has a distinct advantage over the 435Be in this application. It has a rising high frequency response which makes it much easier to set-up with systems using higher sensitivity woofers. With the 435Be on this waveguide you have to trade woofer sensitivity to get a usable last octave response. Attached are plots for the 476Be no network and 435Be with nework and raw.
Rob