Woofers for University Classic

[Horatio]

Hello all:

A few years ago, I built a pair of University Classics, and I fitted these out with Eminence woofers with T/S parameters that ought to have been decent for horn loading (low qts, fs around 45 Hz or so; don't recall the rest, but can dig them up, as I have a file somewhere). I like the horns, but I think the woofers aren't the best fit- lows aren't where I expected them to be, and moreover, with the gentle folding of the 'Classic, I expected to reach 400 Hz and better without much issue. These struggle to make it. I have not tried actively EQ'ing them, but really don't want to go down that path just yet.

My question is, has anyone on this list tried other woofers in this design, and what seems to be the recommendation? The old University C15W does not seem to have published T/S data, so it is difficult to find something that is a reasonable match. I am considering picking up a pair of K33E's, because my experiences with a Speakerlab K showed that the standard W1504's, and some EV15L's were absolutely left in the dust by K33E's. The horns came alive with those K33E's.

Anyone with advice on this? I guess I can buy and try, but if any of you are running a set of Classics and are happy with the woofer choice, I'd like to hear about it.

[ZAKO]

University precedes TS data

[mungkiman]

I don't know anything about T/S parameters, but does this help?

Series Voice Coils

* Piston Diameter = 330.2 mm

* f(s)= 69.98 Hz

* R(e)= 6.63 Ohms

* Z(max)= 74.00 Ohms

* Q(ms)= 3.708

* Q(es)= 0.365

* Q(ts)= 0.332

* V(as)= 91.420 liters (3.228 cubic feet)

* L(e)= 1.41 mH

* n(0)= 8.19 %

* SPL= 101.20 1W/1m

* M(ms)= 58.27 grams

* C(ms)= 0.09 mm/N

* BL= 21.58

Parallel Voice Coils

* Piston Diameter = 330.2 mm

* f(s)= 69.98 Hz

* R(e)= 2.32 Ohms

* Z(max)= 18.89 Ohms

* Q(ms)= 3.965

* Q(es)= 0.554

* Q(ts)= 0.486

* V(as)= 91.420 liters (3.228 cubic feet)

* L(e)= 0.36 mH

* n(0)= 5.39 %

* SPL= 99.42 1W/1m

* M(ms)= 58.27 grams

* C(ms)= 0.09 mm/N

* BL= 10.35

[mungkiman]

Here's another source: http://community.klipsch.com/forums/storage/3/674303/C15W%20woofer.jpg

[tomlang]

I had good luck with the Eminence Legend CB15 in my University Dean (not a Classic, but very close) build. As noted in the link of the build below, I used an extreme slope crossover from the woofer to midrange. I lack measuring equipment but the amount of "highs" coming out of the horn through the Eminence woofer was substantially more before attenuating them with the 600 Hz crossover.

http://www.audiokarma.org/forums/showthread.php?t=380361&highlight=university+dean

[Horatio]

Thanks for that. Checked the T/S specs on the CB15 Legend, and these match very close to circ 1998 K33E T/S data I have tucked away. Unfortunately, those pars are very different from the Crites CS1526, which is pushed as a K33E replacement (CS1526 has quite a bit lower Fs, lower Qts and about 40% bigger Vas, for example, compared to the CB15).

How's the bass on your 'Dean with this driver? It is promising that your high end is up there; this is what I am most concerned about, as I figure the bottom end, with a well-matched driver, ought to take care of itself.

[tomlang]

The bass is kick in your chest kind of bass, not home theatre low but low enough for music it seems to me. At least as low as some Altec Valencia's I once had.

[Horatio]

Tom:

Thanks for that! I finally dug up what I am running in those Classics I built: Eminence 151311, which has these parameters:

Fs = 38Hz

Qts = 0.31

Vas = 299 liters

mms = 60 gm

xmax = 5.5 mm

SPL = 99 dB

Now, that is not a shabby woofer, at least on paper. I was going for as high an Fs value as I could find in a 15" (that had low Qts as well) to improve the uppoer end of the response. The Legend CB15 is reported as having these pars:

Fs = 34 Hz

Qts = 0.34

Vas = 336 liters

mms = 70 grams

xmax = 4.8 mm

SPL = 98

On paper, those two woofers could be mistaken for each other. I have no idea about the actual sound differences!

And the Crites' CS1526: (K33E)

FS: 26.3Hz
SPL: 97dB
Xmax: 7.15mm
Pmax: 150W
Re: 3.36 ohms
Vas: 506.3L
BL: 12.49
Qe: 0.27
Qm: 9.93
Qt: 0.26

It is clear that the woofer I am using and the Legend CB15 have pretty similar specs, as you can see. The Crite's K33E replacement is quite different (and differs from many of the published sets of T/S pars for the K33E that can be found elsewhere on this site).

Hmmmm.

What I DO know is this: I have a set of Speakerlab K's, and I was not happy with the original WS1504's that were in these, and replaced them with EV15L's. Still not what I liked, at least did not sound like the real thing. I bought K33E's from Crites and those babes woke those bass horns right up. Better on the bottom, much better above 250 Hz. I put in the Klipsch Type A or AA (can't recall, right now) and it got better still. In fact, that combo would raise the hair on my neck the way the Klipsch originals would. Never looked back with regard to woofer choice.

I am powerfully inclined to pick up another pair of the K33E replacements and see what these do.

Thanks!

[tomlang]

Horatio, excellent research and summary! If you get the Crites, I will anxiously await what you discover!

[Audio Android]

If you get the Crites, I will anxiously await what you discover!

As will many others just lurking around these parts....[:-*]