Mapman,
What was done to the drivers? That's actually a very interesting question! When I spoke with John, he said something like (and this is a paraphrase from my unreliable memory), "We have a lot of room to play with that tweeter." The impression I got was that he wanted to "goose" or somehow play with the tweeter response. What he did, exactly, I'm not sure, but the difference is palpable right out of the box.
For example, I have a Sheryl Crow greatest hits CD. The recordings are very processed, very "studio" sounding, and yet, very pleasing in their own, rock 'n roll way. The opening instrumental sequence of Every Day Is a Winding Road, begins with some noodling around on an organ (the notes seemed to float in midair... very cool) followed by complex bongo drumming coming from both channels, before the guitars kick in. The first thing I was aware of listening to this track, which I like quite a bit, was that the modified speakers really projected a sense of "fingertips slapping skins" on those bongo drums... I mean, they sounded great before, but now you could really make out the particular percussive surface being played. This was quite startling. Also, I was listening to The Goodbye Look from Donald Fagen's first solo album, which begins with a lot of Marimba and other percussion, and the sense of being surrounded by all those instruments was remarkable.
By the way, for what it's worth, I was interested to see the construction of the drivers themselves. At the bottom of the drivers, you see what looks like a typical speaker cone like you might see on, say, a 4 inch or 5 inch midrange driver. Not knowing any better, it looks as if the driver fires downward into the speaker cabinet... I mean, it seems to have a rubberlike surround and everything. Of course, you can't actually look inside the driver, so you cannot see the cone shaped Walsh radiator. But I do wonder what's actually going on in there...
Both on the old and new set of drivers, that bottom surface that looks like a speaker cone is written on with blue ink or blue paint. There is a date, presumably, the date of manufacture, along with an arrow pointing in the direction of the super tweeter. Also, each set of drivers is painted with the initials "JS" -- presumably, John Strohbeen. Also, the newer set of drivers each has the letters SP (presumably for "special") painted on it. Interesting...
