E-V 15WK

[Don Richard]

The 1959 -1960 K-horns and Cornwalls were incredible speakers, with that 15WK. Sadly, EV discontinued those huge alnico models and substituted a much lighter, cheaper, ceramic magnet model, and those great speakers were never the same. I have always wished that Klipsch would source a 15" model with the old EV's strengths, and engineer the xovers to match. I think the current K-33, while very good, is feeble in comparison. I'm sure economics and the market have made it impossible since 1960.

Part of the difference in sound of the Khorns of that time was the 6 inch wide throat used with the 15WK. I had a 15WK years ago that I tried in my horns with the 3 inch throat and no question about it, the K-33 sounded much better.

[LarryC]

Hm, did Klipsch always use only the 6" throat with the 15WK?

I transferred my solitary 15WK out of a Model T Shorthorn into a utility model K-horn in the late 1960's, which I'm pretty sure had a 3" throat, and it sounded terrific! I could never find another EV 15WK for the other side, and therefore couldn't begin to match the sound quality.

My perception is that the 15WK is so self-sufficient in bass power and musicality that those qualities should come through regardless. OTOH, I got to try a pair of 15WK's, with what looked like original cones, in my AK-4 K-horns, and that didn't work so well, which could bear out your point.

PWK had a real struggle with his products' sound quality for some years after EV discontinued the Alnico 15WK's.

[John Warren]

PWK had a real struggle with his products' sound quality for some years after EV discontinued the Alnico 15WK's.

His challenge was to get something that people would buy using PA type compression drivers and low end tweeters. I would argue he was successful, enormously so.

Why ascribe something special about Alnico v. ceramic v. rare Earth? A highly optimized magnetic structure based on RE material will provide higher flux density in the gap when compared to the "vintage" Alnico motors. This only makes life better if your trying to get to good reproduction, no?

I think horns are fun and great "play things". Getting good sound out of them is a whole different matter and a serious challenge and if your going to make them as a business. You really have to hold your own against direct radiators which, at the starting gate, aren't plagued with bandwidth and phasing errors associated with horn path lengths, air chambers, etc. Not to mention the labor, material costs and WAF all work against the manufacturer too.

[LarryC]

His challenge was to get something that people would buy using PA type compression drivers and low end tweeters. I would argue he was successful, enormously so.

Why ascribe something special about Alnico v. ceramic v. rare Earth? A highly optimized magnetic structure based on RE material will provide higher flux density in the gap when compared to the "vintage" Alnico motors. This only makes life better if your trying to get to good reproduction, no?

I didn't. I used "Alnico" to refer to the previous, much heavier EV series represented by the EV 15WK's shown in this thread. I don't know ceramic from alnico from RE from flux density or you name it, but I do know good, musical sound and the vintage 15WK's had it IMO and the replacements did not. I have no knowledge and made no claims about alnico vs. ceramic vs. RE.

I was referring to the specific ~1960 consumer products that used the 15" driver -- K-horns, Cornwalls, the Model T Shorthorn (I never heard a 15" Model S). I still remember the dealer's great frustration with the tubby, less rich, less detailed sound from new K-horns and Cornwalls with the new woofs, and I certainly agreed. I doubt that most of his customers gave a hang about whether they were PA drivers or low end tweeters, if the end product sounded more like music than JBLs, Altecs, etc.

I did substitute a pair of vintage EV 15WK's in my AK-4 1962-built K-horns once, and quickly heard a poor match. I have no idea why. Maybe, for all I know, they needed a 6" throat, and/or the crossover needed a redesign. But the power and the musical definition of the 15WK, whether in a baffle or in open air, were undeniable.

[John Warren]

I did substitute a pair of vintage EV 15WK's in my AK-4 1962-built K-horns once, and quickly heard a poor match. I have no idea why. Maybe, for all I know, they needed a 6" throat, and/or the crossover needed a redesign. But the power and the musical definition of the 15WK, whether in a baffle or in open air, were undeniable.

I never thought much of the 15WK, low excursion and heavy for the wrong reasons. My preference for the Klipschorn is the ceramic K33P by CTS ( as opposed to the earlier Alnico K33B).

[grindstone]

datasheet page 2: "The precise size of this cavity is dependent on the design application. For further information see bulletin No. 210 on the construction of the Georgian enclosure."

Courtesy of someone here, I've seen the original Georgian DIY manual but that seems not to be it. Anyone know of the bulletin 210?

[John Warren]

datasheet page 2: "The precise size of this cavity is dependent on the design application.

Rear cavity of the folded unit for the "reactance annulling"?

[grindstone]

Fair guess but no idea. My hunch was it was more about loading the compliance to keep from finding xmech but I really have no idea.