Donnie,
I agree about the workability of MDF and even Corian (which I hate the smell of when cutting). One thing that sits on my mind is how nasty MDF is to router bits and the like. They certainly aren't cheap, and I do my best to select a 'good' speed for them to run as well as the right cutting speed. Having said that, I usually am working with some sort of cover of solid wood over the MDF cabinet just to make things heavier, heh heh. i even reverse cut with the router when I am near a corner for the reason that you mentioned about wood, especially plywood! Nothing like that little piece that you can't replace just zinging across the shop.
Now if I were a rich man, some kind of perfect material would be used regardless of price, but for now, it's almost always the usual.

Alex-  This is my simpleton’s take on your question.  It’s not just the driver size that is the determining factor.  The size of the driver along with the cabinet size, type of cabinet and construction details ( folded horn, mass loaded transmission line, bass reflex, open baffle) will impact the room size required. Open baffles don’t have the box to better support the bass so a larger driver can be used and they still often need additional bass support (woofer/sub) depending on room and individual sound preference. How to determine the ideal room size match to a speaker is for the experts to explain…There are others here that can get into the nitty gritty above my understanding…

Hey Alex,

My listening room is approximately 13'x18'x8'.  Currently there are two pairs of rather large open baffle speakers in this space. The PAP Quintets with eight 15" woofers sound fantastic.  I've never once thought that the bass is overwhelming, lacking, or not right. They have been my main system speakers for nearly seven years now.  The bass is really good.

I also have a pair of ZF15L speakers in the room.  The same can be said of these great speakers.  The bass response is fantastic.

Prior to the Quintets I had Zu Audio Definitions which now sell for $25,000 a pair.  Being a box speaker, the bass was horrible--very boomy and unpredictable from one recording to the next.  Prior to that I had the original Azzolina Audio Gran Sferas, that used a modified La Scala bass cabinet that combined a folded horn design with bass reflex.  The bass response was far better than the Definitions, but still boomy and simply too much for the room.  Our family room speakers, old Soliloquy 5.3s with 6" woofers in bass reflex cabs, have also spent some time in the listening room.  Talk about boomy out of control bass!

So, in my room, whether using two 15" OB woofers, or eight 15" OB woofers, bass response is great.  I'm one of those guys that will never go back to box speakers.  OB bass is so natural and real sounding.....even in a small room.