Klipschorn bass response

[bodcaw boy]

Roy, talk about being bent out of shape.

My response was very pointedly in response to the allegation that Heyser's plot was, or may have been, "fabricated". My original post was totally without regard to anything you may have posted. But if you want to interpret anything as being directed to or about you, you are of course free to do as you wish.

And I certainly apologize for responding with a few specific references to things which Heyser did cite in the review.

Heyser did indeed qualifiy much of his measurements, although perhaps not to the extent we might now wish he had. But given the constraints he mentions, I see no problems. Especially as 1/3 octave smoothing was a technique he employed rather liberally as he was well aware of the correlation of perception to measurements and the limitations therein. There really is no need to go out looking for windmills to joust. Just as Heyser had no incentive to "fabricate" anything. And as to whether he employed TEF and TDS, I would love to become aware of other test equipment that easily could have been employed to generate the Nyquist displays - especially in 1986. It is always fun to learn something new.

Have fun. This is one windmill that doesn't present much of a threat. And I suspect, certainly not one for which Heyser would have felt compelled to "fabricate" results.

oooookaaaaaaaaay......[:|]

now where is the next pesky windmill.......[8-|]

roy delgado

[mas]

Roy,

Have a wonderful holiday!

Oh, and as I haven't had an opportunity to say so previously, THANKS for the work you have done and the information you have so graciously shared.

[John Warren]

If Heyser had problems with the measurements he certainly didn't allude to it in the text. He simply stated it's was a "measured response" and when Heyser calls it a measured response, we assume it's done correctly. Who better to measure, the guy invented time-delay spectrometry didn't he?

I still find it unusual to say the least, that one of audio's most respected contributors, having published extensively in the field of loudspeaker measurement, produced an amplitude response that is decidely wrong over the LF range of the response and (of course) wrong in "right" direction.

Still looks like it's just "drawn in" to me

jw

[ZAKO]

Nothing like dotting your i,s & crossing your t,s for history,s sake.

[mas]

If Heyser had problems with the measurements he certainly didn't allude to it in the text. He simply stated it's was a "measured response" and when Heyser calls it a measured response, we assume it's done correctly. Who better to measure, the guy invented time-delay spectrometry didn't he?

I still find it unusual to say the least, that one of audio's most respected contributors, having published extensively in the field of loudspeaker measurement, produced an amplitude response that is decidely wrong over the LF range of the response and (of course) wrong in "right" direction.

Still looks like it's just "drawn in" to me

jw

John, I am rather confused by your maintaining this.

He states this issue quite clearly and of the methods he employed to convolve this response ranging from the corner issues through the tweeter offset and the time issues to his use of the 13 mS window of the ETC to convolve the frequency response from the 'time slice' on pages 65-68! I am not trying to sound like a smart aleck, but are you familiar with the methods of convolving a frequency response from the ETC to which he is referring? Selecting the particular time slice will effectively remove some of the environmental pollution occurring later in time window that is integral to other frequency domain measuring methods and cannot be removed. As he mentions, how does one totally remove the room when the room is a fundamental part of the corner system being measured!? [] The KHorn is definately not a point source. LOL []

The irony is that he actually went to more exhaustive lengths than some who might simply stick a mic in front of the unit or even lay it on the ground in a quasi-PZM configuration reducing various boundary effects as Don Keele pioneered and has employed for many years.

There are ramifications to employing different methodologies. But understanding the constraints should help to illuminate the measurement and not simply result in dismissing a measurement or declaring it "decidedly wrong". May I suggest that we enlarge our scope of understanding rather than dismissing a rather complex methodology that Heyser employed as he has taken various time domain responses with various orientation considerations and convolved the frequency response from them. (One thing that would help would be to know the resolution, etc. that Dick chose in convolving the frequency...) I am curious as to how you would have addressed the fundmental issues that Heyser attempted to address differently. I suspect any differences in curves are a result of the methodology employed, and Heyser has very specifically attempted to remove extraneous 'clutter' from the measurements while simultaneously being very specific about some of the considerations and limitations addressed.

It seems to me that a fundamental issue is to what degree one is able to view a system in isolation from the environment in which it exists. Some systems are rather easy to do this. But the KHorn does present a very interesting contradiction in terms, as it includes the environmental nexus as a fundamental part of the system. And our results will necessarily be conditioned by the decisions we make in defining the question - including wjat aspects of the environment are to be included and how it is done. It appears that Dick chose to use selective time windowing of the ETC and impulse displays to convolve the various frequency 'segments'. He also apparently adjusted for time offsets in regards to driver offsets as well. There remain lots of interesting questions, but I would not label any of it fabrication or dismiss it without understanding exactly what he was doing.

This seems to me to be an opportunity to explore various techniques and technologies further, or at least a point for future exploration...and it also points to a deeper understanding of the implications of time based measurement - and dismissing one out of hand does not seem to be most prudent response.

But have fun...as I do not mean to drive this conversation in another direction. But this issue does speak directly to the various methodologies employed in mapping one topological space into another.

[John Warren]

In Heyser's eagerness to cull "environmental pollution" from the response his "convolution" dismissed a good deal of the real response of the LF horn. The article merely illustrates deficiencies in the simulation method he used at attempting to recreate a free-field response (i.e. anechoic chamber response) in his living room. This is what Roy's commented on earlier.

Bottom line...We have the benchmark to compare his convolution against and it doesn't trend, even remotely.

Also, there is a "tongue-in-cheek" reference to his "free-feild" response in the upper left-hand corner of p.68 (quotes not mine). It appears to be an editors embellishment but may be more telling.

The article was intended to be an advertisement. As Nietsche once said (loosely translated) "I listened for criticism but all I got was praise".

[ClaudeJ1]

"The article was intended to be an advertisement." John Warren.

Your last sentence is the best one out of the 126 posts. Since I got to spend a good 10 hours mono y mono (my wife understood) with PWK in 1985 and I spoke with Jim Hunter for at least an hour (his beer bottle collection must be huge by now), I got to ask lots of questions.

One of them was about Dick Heyser and TDS. PWK mentioned that while "phase coherency" was not the strong suit of a Khorn, it was deemed to be very low on "things to achieve" when it comes to human detectability on speech and music. I also asked about monster cables and PWK's reply was "it's and expensive way to supply current to a 30 AWG voice coil." Even as far back as 1985, PWK (he was 81, remember) was not as intimately involved in every day details and he didn't seem to trumpet (pun inteded) too many decisions made by marketing and sales. But even he was somewhat surprised at how large the company had gotten. Let's face it, the Heresy saved K&A from going broke and it's the smaller/cheaper speakers that pay the bills not the Khorn.

He did have a lot of respect for the Dick Heyser, but Dick LIKED the Khorns, even though they may have been at odds with the quasi-religious meanderings of the lay press at the time, concerning the relative importance of TDS in speaker design. Without getting too romantic about it, it's simply just another way (on the list of many) to test things and shows unique forms of data, but it's not the be all to end all.

As a magazine author in 2 different fields, with over 150 published articles, I have had a chance to review many products, hardware and sofware wise. If I didn't like something, it never made it to press. If I did like something I wrote it up and it got published. That is not to say you can't offer opinion on your own perception of product flaws. But, overall, when advertizing pay the bills, you can't trash a product AND ask for money.

It has been 20 years or more since I read that arcticle, and what I got out of it was that Dick found the TRANSIENT response of horn bass to sound more REAL than his custom subwoofer designed to go flat to 10 Hz.

Bottom line? Paul was RIGHT!!!

Claude

[John Warren]

Your last sentence is the best one out of the 126 posts.

Claude

You see, even a broken clock is right twice a day!

[ZAKO]

John.....It was only ment to be a review.......Not a technical paper submited to a science journal.

[bodcaw boy]

the way data is presented and, i would hope, since reviews are there to help people gather info, that the data would be as close to accurate as one could get it. just my opinion.

roy delgado

[John Warren]

Roy-

Did Klipsch ever change the "splay" angle of production Klipschorn bass units? (where splay angle is defined here as the angle of the "V" looking top-down onto the bass unit). I have early 80s units here that measure 63 degrees.

jw

[ZAKO]

Merry Christmas John.....My 72 Klipsch has a splay angle of about 63 degrees. very interesting observation.

[ZAKO]

Roy...Remember the plot data drawings, was done in the Graphic Dept. by associate art director Linda Zerelia..Who had responsibility for page makeup. The graphs do look modified for visual enhansment....Ive never seen color ink plots that thick (more like felt tip) No one knows if each final page was checked for accuracy. Graph charts look like they came from the art dept. rather than the chart paper & plot recorder I use. Its also obvious proof reading did not catch the details. I would not chuck out the review because 99.9 percent was excellent....Just to niggle over .1 percent flawed

[bodcaw boy]

Roy-

Did Klipsch ever change the "splay" angle of production Klipschorn bass units? (where splay angle is defined here as the angle of the "V" looking top-down onto the bass unit). I have early 80s units here that measure 63 degrees.

jw

not that i know of....

roy delgado

[bodcaw boy]

Roy...Remember the plot data drawings, was done in the Graphic Dept. by associate art director Linda Zerelia..Who had responsibility for page makeup. The graphs do look modified for visual enhansment....Ive never seen color ink plots that thick (more like felt tip) No one knows if each final page was checked for accuracy. Graph charts look like they came from the art dept. rather than the chart paper & plot recorder I use. Its also obvious proof reading did not catch the details. I would not chuck out the review because 99.9 percent was excellent....Just to niggle over .1 percent flawed

oh i am only too aware of that (it tends to happen here at our marketing dept []). and no one is saying to throw out the review over this. john brought it up for discussion is all and that is what we were doing. i hope that we are allowed to discuss it.........[:^)]

roy delgado

[ZAKO]

Bob ....Sure....Discuss all you want.... But it reminds me of an obsessive engineer in my dept....One day he came in with all these drawings & blue prints in his arms...I asked " what do you have there?" He said..." Its a design of a reconnaissance camera that takes a picture of its self". We gave him a three month leave of absence to rest.

[bodcaw boy]

Bob ....Sure....Discuss all you want.... But it reminds me of an obsessive engineer in my dept....One day he came in with all these drawings & blue prints in his arms...I asked " what do you have there?" He said..." Its a design of a reconnaissance camera that takes a picture of its self". We gave him a three month leave of absence to rest.

that's me, quite the obsessive one....although i don't remember spending quality obsessive time in meeting you......

roy delgado

[ZAKO]

Yes and we paid him full time pay for three months. while he was on leave. He was too valuble. hard to replace. No I,m not going to pay you to obsess with me. Not even a slab of ribs.

[bodcaw boy]

then how about the ice cream, at least....

roy delgado

[ZAKO]

Obsessivness can be a double edge sword...We learn the scripting before we are five. The good side like Einstein. The bad side like Son of Sam. Ice cream is good when your young but could contribute to your demize later in life.. A book By Eric Byrne " I,m OK You,r OK Transaxial Analisis explanes how we set up our life,s script. This is what sets up our enique personality. The difference between Mozart & Beethoven.