Shorthorn Impedence Question

[JRklipsch]

Hi,

I have been working on a restoration project of a pair of Klipsch Shorthorns, I have finished one speaker cabinet and working on the second but I do have a driver/crossover question. I have a K-1000-5000-W crossover, T-35 tweeter horns (8 Ohms), K-55-V (16 Ohm?), and K-33 Woofers (4 Ohm?) What are the correct impedences of the drivers for this crossover? I have an old sales sheet that shows you can buy an upgrade for the K-Ortho to a K-77, K-55, K-33 driver compliment, but do you have to change the crossover? I beleive the University SA-HF is 16 ohm, what about the K-77/T-35, and the K-33/Stephens Trusonic Woofer?

I have been looking for the original drivers, but I wanted to use what I had for time being, will these work?

Thanks,

John

[CaptnBob]

Hi, JR,

On my Shorthorns the tweeter and midrange are 16 ohms and the woofer is nominally 4 ohms. The cabinet loading brings the woofer impedance up.

Having differing impedances will move your crossover points around, but I'm not sure where. I just discovered I've been using an 8 ohm T-35 in one Shorthorn for years without any deleterious effects. (Somewhere along the line the 16 ohm voice coil was replaced with an 8.)

Glad to hear your project is coming along.

Capt'n Bob

[mungkiman]

JR,

I have '59 Shorthorn 15's with K-1000-5000 networks. The K-77's are 16 Ohm and the SA-HF's are 16 Ohms, but the Stephens Trusonic 103LX woofers are also 16 Ohm with a DCR of 10. The faceplates on these networks are stamped 16 Ohm as well. You might have to alter the tap setting on mine to use a K-33-E woofer, but you probably wouldn't with Capt'n Bob's. The tap settings on mine are: 4,2, and 0. Hope this helps.

Chris

[Jim Cornell]

I believe they are rated at 16ohms, same as the Klipschorns in the same era!

Jim

[JRklipsch]

Hi Guys,

The EV T-35s are rated 8 Ohms. I guess I will have to find another tweeter horn, the speakers sound realy nice as is. I was suprised at the amount of bass they put out. I had read that the Shorthorn was Bass poor, but mated with a K-Horn it rounded out the stereo image as the high frequency horns matched. Eventhough they do not have near the bass my K-Horns do, they are respectable.

So, am I correct to say that having different impedence drivers changes the crossover point only and will not otherwise damage the speaker or amp?

I would like to thank Capt'n Bob and Mungkiman for all the measurements and help you have given me on this project. I have not had as much time to work on them as I would like, but one cabinet is finished and the other about 75%. I have included a picture so you can see my progress.

Thanks,

John

[Stovebolt6]

Wow! That looks fantastic!

Nice job John!

[Randy Bey]

Gorgeous, you should be proud.

[CaptnBob]

Nice work!

The only problem as far as damaging the speakers goes is if you drop the crossover point below what the tweeter or squawker can comfortably handle.

I must respectfully disagree...

The 15WK (The "K" is usually a very small stamping on the back plate after the "15-W")is the four ohm version of the Electro-Voice woofer - the one designed for folded horns. If yours are 16 ohms, they may have been reconed somewhere along the line. But as far as I know, the woofers in Klipshorns, Patricians, Centurions, Georgians, Shorthorns, Regals and even Cornwalls are supposed to be 4 ohms.

I tried a pair of 16 ohm Altec 515bs in my Shorthorns for a while. They went plenty deep, but seemed about 6db down from everything else.

Capt'n Bob (stirring up trouble as usual.)

[Malcolm]

The relevant EV literature shows the 15WK as having 16 ohms nominal impedance and 3.2 ohms DCR.

[CaptnBob]

Exactly - when it's in the cabinet the amplifier will see the 15WK as a 16 ohm load. But if you test it with an ohm meter, it will register a resistance of about 3.2 ohms - which is what 4 ohm drivers usually do.