note from PWK 1985 re: T-S paraneters

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I don't currently have a scanner but will get a scan. I asked PWK about T-S and here's the content of his reply

PAUL W. KLIPSCH
President

May 1, 1985

Dear Mr. Ireson:

The Thiele parameters apply to direct - radiator speakers (closed box and bass - reflex) and not to horns.

If you put a wrong driver in a KLIPSCHORN you will not get acceptable response.

Sincerely,
Paul W. Klipsch
 
I don't currently have a scanner but will get a scan. I asked PWK about T-S and here's the content of his reply

PAUL W. KLIPSCH
President

May 1, 1985

Dear Mr. Ireson:

The Thiele parameters apply to direct - radiator speakers (closed box and bass - reflex) and not to horns.

If you put a wrong driver in a KLIPSCHORN you will not get acceptable response.

Sincerely,
Paul W. Klipsch

Hi freddi,

Fascinating stuff - thanks for posting!

It is interesting that in May 1977, Don Keele, working for Klipsch & Associates at the time, presented an AES paper entitled "Low-Frequency Horn Design using Thiele/Small Driver Parameters" :).

Kind regards,

David
 
Better not tell David that - Hornresp uses t/s parameters to sim horns, LOL.

Hi Brian,

Just to clarify - Hornresp does not actually use T-S driver parameters in any of its simulation models (horn or direct radiator). It uses the traditional electro-mechanical parameters Sd, Bl, Cms, Rms, Mmd, Le and Re, as shown on the input parameters window :).

Kind regards,

David
 
here's a scan of that note. IIRC, I once had another note from PWK where he poked some fun at "T-S parameters" - perhaps like he didn't know what they were :D

5e3JRad.jpg
 
Just to clarify - Hornresp does not actually use T-S driver parameters in any of its simulation models (horn or direct radiator). It uses the traditional electro-mechanical parameters Sd, Bl, Cms, Rms, Mmd, Le and Re, as shown on the input parameters window :).

Yeah, but they're all directly related :). Hornresp will actually do the conversion if the driver's t/s parameters are provided on the "Input Parameters" screen after double-clicking the "Sd" field.
 
No Button!

TS parameters are derived form measurements of low frequency, small signal driver performance. To arrive at an optimal match between horn and driver parameters to fill a particular acoustic mission requires evaluation of much more. How you characterize driver performance does not change the quality of the design effort so long as such is used appropriately. I find PWK's brevity amusing. WHG
 
Models supposedly simulating drivers, boxes., ports, horns, and other acoustic elements based on idealizations of the three basic electric elements have been around a long time.

Thiele (with the later supplementation of Small) devised coherent ways to compute these models, although without much empirical verification himself and, to my eyes, much actual creative contribution. As McBean and Klipsch say, you don't need their computational approach to calculate your models. But today we just call it "T/S" to characterize the whole design field.

Simple models are simple. Are the accordion edge and spider of your driver perfect springs? Is the VC a perfect coil as it moves in and out and for all frequencies? Parameters stable from taking out of carton until a year later? And when the cone segments? And the height off the floor and the room walls? What else influences the driver besides the handful of model elements?

Not saying the simple model is erroneous. Just simple.

B.
 
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