No expert at all, but I do keep my ears open!! :)
Thanks though for the kind words. It does help that I've been around them now for (yikes) about 15 years or so.
If we only count production models, I think there are three. The 'original' that has small supports inside the bass bin to hold the sides still (there is a story there too). Roy redesigned it to create the updated version that had "shelves" going all the way around the bass bin. By using the 'shelf' it was easier, faster to produce and made a stronger cabinet.
I'm guessing in the engineering world, that might be a win/win/win??!!
The "story" on the supports....
Years ago, it seems Roy/Klipsch got some complaints about the Jubilee bass bin resonating. Not all of them, just one here and one there. It was an inconsistent issue.
He finally figured it out. It turned out the manufacturing company that provided them the plywood for the cabinets was the culprit. I don't know the specifications, so let's just say that Klipsch spec'ed the plywood for the Jubilee to be .75 inches, plus/minus .03 inches.
He found out that the company producing the plywood was able to be pretty consistent with the plywood thickness. and it generally came in say, .74 to .73 (but ironically, hardly ever OVER .75!
None the less he discovered that when the production was (for example) .73 and THAT thickness was used for the rear panel, they had a terrible resonate problem..... if it was thicker, then the resonate issue wasn't there (or was greatly reduced ??). So he put those supports in much like some folks put a support in the mouth of a LaScala to keep the side walls from resonating.....essentially the same issue.
So he put those support wings/tabs in there and that cleared it up but I don't think he liked the in-elegance of that.....so went back several years later and redesigned it with (what I call) the 'shelf's' in there which also guaranteed the problem was fixed, made a stronger cabinet, easier to build and in my mind, looks nicer.
So that would be (as best I know) the second version and the third would be the one pending with the vented horn where he's taken one of the drivers (Jubilee uses two 12" drivers) OUT of the bass bin and he's ported that space or something to somewhere of the horn. I'm not sure what he's done other than the video that Klipsch has posted about it.
