K-51V Klipsch Midrange Driver

[BEC]

I bought a pair of these that were on K-600 horns awhile back. First time I had ever heard of them. They test a lot like the K-55M on the specturm analyzer but extend a bit higher in frequency.

Since one of them was bad when I got them, gave me a good reason to take one apart to see how the insides look. Uses the same diaphragm as the K-55V.

Pictures to follow.

Bob Crites

[BEC]

The back.

[BEC]

The front.

[BEC]

Inside with diaphragm removed. Notice 2 piece phase plug and perhaps you can make out the name Atlas Sound at the bottom edge.

[BEC]

This picture is the diaphragm mount on the K-55V spring terminal type to show the 1 piece phase plug.

Bob Crites

[dodger]

Thanks BEC, appreciated

Hope all is well.

dodger

[Deang]

The K-51-V is the ceramic magnet version of the K-55-V (with soldered terminals).

[BEC]

Dean,

That is something I would like to get cleared up. "V" has meant alnico in typical Klipsch labeling. I can't tell the magnet material by seeing the driver apart, but since it is marked K-51V, I think it would be alnico.

Bob Crites

[djk]

Sure looks like a ceramic magnet K51V to me. Give it the screwdriver test, an alnico one is virtually shielded.

[Hardhead]

I seem to remember some discussion about Klipsch having problems with the K-51-V driver. It was used for only about a year, I think--that says a lot in my book.

[dodger]

If that is the same as the Atlas mentioned in another Forum, It is alnico.

I would be willing to send it to Bob to allow him to analyze it.

[dodger]

It was time to put this to bed.

I called Hope.

Years ago I had dealt quite a bit with Hope, prior to Indy. Ironically there was a very nice person named Hope that I would speak with.

The Operator is one of the most pleasant people I have talked with.

I called, spoke with a very nice person that said, "sounds like the K-55v." We discussed further how I obtained the horn and Driver - a definite yes, the PD 4V WAS used as a K-55v - the v being a designation for alnico. Atlas would run out of the 5, the 4 was used in the Heresy and some other models.

It was used in a number of Heresys. Those I have noted had the spring terminals. (Push-in, insert wire)

Also, those have had AS the Atlas a "stripe" of reddish orange paint for the positive terminal. 3 pins - raised.

As this was a toll call for me, I tried to verify as strongly as possible, without being obnoxious to someone that nice.

I am in his debt as I also am to the Operator for her kindness.

dodger

[mike stehr]

"I seem to remember some discussion about Klipsch having problems with the K-51-V driver. It was used for only about a year, I think--that says a lot in my book."

Can you elaborate?

Mine seem to be working just fine.

[BEC]

I can see no obvious reason that the K-51V should not be as good or perhaps a better driver than either the K-55V or the K-55M. Seems built a lot like those as far as I can see and its frequency response is perhaps a bit better than either.

On the subject of Alnico or Ceramic for the magnet. I think I would have to take off the nice rubberized covering to tell that by examination. I can say that as far as the screwdriver test goes, it is more attractive of a screwdriver at the side than is the K-55V but much less than the K-55M. I think that it is likely that the large iron bell covering the magnet assembly of the K-55V is the reason little magnetism is felt outside of that one. Obviously the K-51V does not have that bell. I can say that either it is alnico or Klipsch should have marked it K-51M to hold to their convention.

Bob Crites

[Deang]

Win, your source in Hope is incorrect. The 'V' is the designation for Atlas, just as the 'M' is the designation for Electrovoice. The last character specifies the vendor, not the magnet material. The dual port K-55-V and K-51-V are identical with the exception of the magnet material. When Electrovoice presented their own dual port phase plug ceramic version, the Atlas K-51-V was dropped by Klipsch, and they went with the new Electrovoice driver, designating it the K-55-M.

As a side note: if 'V' means Alnico, and 'M' means ceramic, then what is 'H', as in the K-52-H? I think the 'H' means Hepner, and I'm pretty sure that's not a magnetic material.

[BEC]

Dean,

Then the "X" in K-55X would mean??

Bob

[WMcD]

I thought there was a little joke in X.

Firesign Theater had a little quip about movies (?).

"X" the unknown, absolutely no one admitted.

Gil

[Deang]

"Then the "X" in K-55-X would mean?"

Evidently it's the new designation for Atlas. Probably changed to differentiate it from the older Atlas units before the Heritage "redesign". As far as why Klipsch felt the need to do this -- your guess is as good as mine.

Maybe Gil is right.

[dodger]

I have tried not to be a smart snot, but the sources years ago that I purchased from were Authorized Klipsch Dealers and an Authorized Klipsch Rep.

We all know many different drivers were used.

I have double checked the part number, called Klipsch at my expense an also did find from Atlas information.

Between the other thread regarding Heritage and this one, I felt I was conveying information.

As its said, I was born in the afternoon, but it wasn't yesterday afternoon.

Atlas confirmed the alnico.

But there have been no quirks, no substitutions, etc. in manufacturing. I believe you all now.

I have wasted my time and money for nothing. I have a life not attacking or trying to prove someone wrong. At this point I don't care whether anyone gets any information about the driver - 1 - because it has ceased to matter, 2. I have a life full of more important private things..

I own it, I have it. I have a spec sheet now. It's part of one of my alarm systems. It does a great job, if I have a driver go bad I can use this until I get a correct one.

Win EDITED: TO delete names and for clarification. END EDIT

[dodger]

edit