Well, if we are going to keep this discussion going further I think there are a few things that need to be defined in the idea of this design research.
Most of us have settled on a 2 Way design WG/CD up top and a 15 (Or 12) on the bottom.
The next step is to agree what we want down low, lock that in place so we can start to get to work on this WG design.
Yes Penn wants a larger WG than some of the others out there, I say why not. That though, is because I have the space and now WAF to worry about.
So, Let's discuss what we want the LF driver to be. Most of us who are reading this have built some sort of sub (pure assumption) and are pretty much happy with it. So let's assume for a minute that we don't need to get super low with these things, (I know, you can burn me at the stake later). Can we still get a 15 to play nice like a 12 would? As was pointed out, it really depends on the driver and the specs as well as a whole manner of other things that we can deal with in the future like exact enclosure size sealed/ported etc.
It also seems that we should pick and stick to a CD (though the 250 seems popular) I cannot help at all on this matter as I have not heard any of them yet.
I should also add that what truly got me interested in the entire WG EWave build idea was this simple statement:
augerpro / Branon
In his thread about his Wave variant.
The ability to play loud and clean is obviously a goal, but so is the ability to also be delicate when needed. It should be able to go from Wagner to Chemical Brothers to Diana Krall with equal ease. This became a goal as I was listening to a Led Zeppelin song that perfectly captures what this speaker is all about, No Quarter
Obviously We are not trying to mimic this design, I just wanted to point out the reason I am so interested in it is 2ch Audio. If I am going to spend the time and effort on designing/building something, I want it to be as awesome as I can possibly build.
So, lets start to iron out what we want out of this design. If that means we have to compromise something, then lets discuss it and see if we are ok with making that compromise, and then settle on a design.