'been a while since I posted on this forum (horatio, but I could not get past the sign in gatekeeper with that, so I created a second one).
I built a set of the University Classics a few years ago, and got an Eminence woofer that specs out almost the same as a K33E (fs is 38 instead of 26, but other params are quite close). I was underwhelmed with this. Bass didn't go low enough, highs, not high enough.
After quite a bit of searching, seems like people like the original University 15" driver, for which there does not seem to be a modern equivalent.
But, there are posts by those who've used a K33E and an Eminence CB15 in the 'Classic, and were pleased. I am puzzled by this to no end. And all the sims everyone posts leave me cool (sorry guys, but, no one's been able to successfully model up the Khorn and tell why the K33E params work in it, either).
Here's what I have done, though: using Keele's bass horn relationships, I computed the throat and chamber volume for the speakerbuilder TS params for the University driver (series VCs), and I got a throat area and Vb that were just about spot on for what the Classic design is, if I presume a 50 Hz Fc on the flare.
Now here's where it gets interesting: running the numbers for the K33E (and my other Eminence that is in these cabs), and even the CB15 shows that the throat area and Vb of the Classic is not too closely matched by those drivers.
But the Kappa Pro 15C (from the Eminence published data sheet) comes in pretty darn close to the throat area (6x13 slot) and Vb (80 liters, give or take, as computed elsewhere on this thread). So if you believe the equations, the Kappa 15C looks to have the right stuff. It's just that the T/S parameters roll up another way on their way to hitting the target St and Vb values. The 15C should have good upper end, too, to deal with the problem of reaching 400 hz.
Anyone compute the actual design flare rate on this animal?
I figure to make this box really work, a good dsp crossover and biamping is the very least needed. My final Khorn build (which I call the 'Ultra', since I have not heard anything close since) uses a MiniDsp and is biamped with 100W MOSFET bass and a single ended triode of a handful of watts going into Altec 288's mounted to EV HR6040 CD horns. Uses the Le Clea'ch crossover topology, and the top is time aligned. Crosses at 300 Hz to avoid the upper end problem of the Khorn. Images in a way you can't believe for a horn system. Sweetness does not begin to describe it. Some day I'll go listen to a 'Jub, and see what that fuss was about.
I figure a similar go on the Classics ought to make these pretty good, too: I have a pair of EV HR9040's ('great whites') and the EV drivers for these (DH1012) and those are quite spectacular, just enormous in size. But they sit nicely on top of the Classics (laying long side down, now).
Anyway, looks to be my project this summer: Kappa 15C's and a miniDSP to biamped configuration.
-H2
