Klipschorn bass response

[John Warren]

Here's the response, you be the judge.

[John Warren]

Compare to the JAES article response-

[bodcaw boy]

john,

what are the conditions of the measurements? he calls them free field but a khorn can't be measured in free space because the khorn has no back walls. if i know mr. heyer (whom paul was VERY fond of and they were very good friends), he used some sort of time measurement which would negate the 1/8 space loading but still capture the first amplitude arrival and hence, would explain the graph somewhat better.

roy delgado

[John Warren]

Roy-

Not sure although the measurements are taken at 3.5m.

The text that accompanies the fig. is as follows (verbatum):

"Figure 4. shows the measured free-field amplitude of sound presssure as a function of frequency for a constant drive voltage corresponding to 1 average Watt into 4 Ohms. The plot is corrected for an equivalent distance of 1 meter on axis relative to the front of the enclosure although the actual distance is 3.5 meters."

Food for thought.

jw

[mas]

Differences in gain are easily adjusted for distance! Dare I suggest the thought is being focused upon the wrong aspects of the review! And it is rather ironic that Dick almost dismisses the frequency response as quite adequate only to move on to much more significant aspects of the analysis. If only we would do the same! There is indeed life beyond an RTA (although many here are quick to suggest that it is uninhabited!)

The article also actually explains quite allot about the parameters chosen, including the specification that the mid and upper frequency response corresponds to an isolated 13 mS of the sound arrival window (displayed in the ETC). I dare say that one not using a time domain measuring device such as TEF, EASERA, MLSSA or Smaart cannot isolate this window! Thus to compare a measurement taken strictly in the frequency domain with more limited frequency domain instrumentation does not address the 'same' event window and does not isolate the speaker from the more detrimental superposed room horizon...especially as we are dealing with what is essentially a delayed array system. May I also suggest that a greater understanding of the time windowing capabilities of time based equipment such as TEF (et al) as well as the restrictions Heyser placed upon the measurements due to the 1/8 corner loading described on page 65 and time offsets actually explain quite a bit.

I see nothing wrong with any of the measurements. The Nyquist, ETC and impulse displays are actually much more instructive than the frequency response curves which are actually of very little value and benefit when viewed in the total scheme of things. It is a shame that the real value of what Heyser was trying to show us (which is but a tip of the iceberg) is the part almost dismissed and subsequently ignored in favor of the least significant measurement. And it is a shame that we tend to dismiss what we do not understand and instead expect someone such as Heyser to cater to our lack of awareness rather than to expand our understanding to approach some of the insights that he chose to share!

I do not, nor do I expect anyone to understand everything. But may I suggest that our ignorance is not grounds to question the integrity of someone who quite literally possessed a much greater understanding of acoustical phenomena than any of us (to the degree that I am aware!).

[bodcaw boy]

Differences in gain are easily adjusted for distance! Dare I suggest the thought is being focused upon the wrong aspects of the review! And it is rather ironic that Dick almost dismisses the frequency response as quite adequate only to move on to much more significant aspects of the analysis. If only we would do the same! There is indeed life beyond an RTA (although many here are quick to suggest that it is uninhabited!)

The article also actually explains quite allot about the parameters chosen, including the specification that the mid and upper frequency response corresponds to an isolated 13 mS of the sound arrival window (displayed in the ETC). I dare say that one not using a time domain measuring device such as TEF, EASERA, MLSSA or Smaart cannot isolate this window! Thus to compare a measurement taken strictly in the frequency domain with more limited frequency domain instrumentation does not address the 'same' event window and does not isolate the speaker from the more detrimental superposed room horizon...especially as we are dealing with what is essentially a delayed array system. May I also suggest that a greater understanding of the time windowing capabilities of time based equipment such as TEF (et al) as well as the restrictions Heyser placed upon the measurements due to the 1/8 corner loading described on page 65 and time offsets actually explain quite a bit.

I see nothing wrong with any of the measurements. The Nyquist, ETC and impulse displays are actually much more instructive than the frequency response curves which are actually of very little value and benefit when viewed in the total scheme of things. It is a shame that the real value of what Heyser was trying to show us (which is but a tip of the iceberg) is the part almost dismissed and subsequently ignored in favor of the least significant measurement. And it is a shame that we tend to dismiss what we do not understand and instead expect someone such as Heyser to cater to our lack of awareness rather than to expand our understanding to approach some of the insights that he chose to share!

I do not, nor do I expect anyone to understand everything. But may I suggest that our ignorance is not grounds to question the integrity of someone who quite literally possessed a much greater understanding of acoustical phenomena than any of us (to the degree that I am aware!).

dude,

what are you saying?

i hope that you are not implying that only you can grasp what heyser does. i admire his work quite a bit and became quite fascinated by his work (so did paul).

i only am trying account for the difference in freq responses because how you measure does make a difference (i do trust his measurements cause he earned it!!). if he did indeed (and try to remember this, i do not have the article) use tef or some time domain analysis, then it would make sense to me why the curves are different and knowing heyser and his work, i would bet that he did use tef.

Nyquist, ETC and impulse displays are instructive before the fact. if the designer knows this things up front then he can choose to improve the components and then use them to improve the system. to display these pieces of data after your done is like saying, i hate the color of the bricks on my house after the house has been built. by then, its too late.

roy delgado

[John Warren]

Mas-

No one is arguing about the context of the article beyond the amplitude response. The discussion is amplitude response.

Regarding the measurement method taken in Fig. 4, nothing above what I stated is said other than the distance the measurements were taken from. Nor am I discussing any of the other measuremets shown in the article. I am only discussing the amplitude response, nothing else.

There is no question that a very "significant" difference exists between Heyser's measurements that the anechoic measurements taken by Roy. That difference requires an explanation. If you see nothing unusual about the Heyser plot than so be it.

I have a different take on it.

jw

[ZAKO]

I believe I would stand behind Mac on this one....No one on this Forum could hold a candle to Heyser on scientific audio background.

[mikebse2a3]

Roy if your interested check your work e-mail for info on the Heyser Review.

For those wondering about the Khorn that was tested by Heyser it is in the Museum in Hope along with the Empty Cabinet used for the Cover Photo(The One Actually Tested was in a Walnut Finish. I had wondered for many years which networks was used/tested for the review and it was the AK-2.

mike tn[]

[mikebse2a3]

Network in the Khorn tested in the Audio Magazine Review

mike tn

[mikebse2a3]

Serial Tag on Khorn Reviewed.

This Khorn of course used the K55M/K77M drivers

miketn

[mikebse2a3]

Actual Khorn Tested was in a Walnut Finish

mike tn

[mikebse2a3]

This is the Empty Khorn cabinet used for the Cover Photo Shot

mike tn

[ZAKO]

Beautiful grain pattern....I wonder who ownes that French horn on that cover photo shot?

[bodcaw boy]

I believe I would stand behind Mac on this one....No one on this Forum could hold a candle to Heyser on scientific audio background.

and just who said they did?

roy delgado

[mas]

Differences in gain are easily adjusted for distance! Dare I suggest the thought is being focused upon the wrong aspects of the review! And it is rather ironic that Dick almost dismisses the frequency response as quite adequate only to move on to much more significant aspects of the analysis. If only we would do the same! There is indeed life beyond an RTA (although many here are quick to suggest that it is uninhabited!)

The article also actually explains quite allot about the parameters chosen, including the specification that the mid and upper frequency response corresponds to an isolated 13 mS of the sound arrival window (displayed in the ETC). I dare say that one not using a time domain measuring device such as TEF, EASERA, MLSSA or Smaart cannot isolate this window! Thus to compare a measurement taken strictly in the frequency domain with more limited frequency domain instrumentation does not address the 'same' event window and does not isolate the speaker from the more detrimental superposed room horizon...especially as we are dealing with what is essentially a delayed array system. May I also suggest that a greater understanding of the time windowing capabilities of time based equipment such as TEF (et al) as well as the restrictions Heyser placed upon the measurements due to the 1/8 corner loading described on page 65 and time offsets actually explain quite a bit.

I see nothing wrong with any of the measurements. The Nyquist, ETC and impulse displays are actually much more instructive than the frequency response curves which are actually of very little value and benefit when viewed in the total scheme of things. It is a shame that the real value of what Heyser was trying to show us (which is but a tip of the iceberg) is the part almost dismissed and subsequently ignored in favor of the least significant measurement. And it is a shame that we tend to dismiss what we do not understand and instead expect someone such as Heyser to cater to our lack of awareness rather than to expand our understanding to approach some of the insights that he chose to share!

I do not, nor do I expect anyone to understand everything. But may I suggest that our ignorance is not grounds to question the integrity of someone who quite literally possessed a much greater understanding of acoustical phenomena than any of us (to the degree that I am aware!).

dude,

what are you saying?

i hope that you are not implying that only you can grasp what heyser does. i admire his work quite a bit and became quite fascinated by his work (so did paul).

i only am trying account for the difference in freq responses because how you measure does make a difference (i do trust his measurements cause he earned it!!). if he did indeed (and try to remember this, i do not have the article) use tef or some time domain analysis, then it would make sense to me why the curves are different and knowing heyser and his work, i would bet that he did use tef.

Nyquist, ETC and impulse displays are instructive before the fact. if the designer knows this things up front then he can choose to improve the components and then use them to improve the system. to display these pieces of data after your done is like saying, i hate the color of the bricks on my house after the house has been built. by then, its too late.

roy delgado

Well, may I suggest you read the review. I have sometimes felt it to be an advantage to read it before debating it.

As far as what is useful for design....OK....unfortunately the article by Heyser is a review. And reviews are typically done after a product is built. To fault reviews for not being done before the product is built would, I suspect, cause others a bit of concern.

And Nyquist, etc. displays are quite useful to understand what is happening after something is built as well! Thus I suspect this may be why Heyser chose to employ them. I realize that I far out on a limb on this one, but that's my guess!

I also trust his measurement! That is exactly my point! But it seems some are more concerned that a review is done after the fact than with the allegation that Heyser "fabricated" and hence falsified results. Heyser mentions plenty of caveats, and qualifications for his methods. Does he explain them completely to the degree some would hope? Probably not. Do we need to guess whether he used a prototype of the TEF. Well, as he mentions he did, and many of the plots are watermarked "TEF", I suspect we needn't guess.

My response was to John's allegation regarding the fabrication of the measurement (as I have quite enjoyed his other posts!) There are plenty of things to discuss in evidence (if one actually reads what Heyser wrote) without manufacturing crises based upon our ignore-ance of what information is provided.

One step at a time.

[bodcaw boy]

Differences in gain are easily adjusted for distance! Dare I suggest the thought is being focused upon the wrong aspects of the review! And it is rather ironic that Dick almost dismisses the frequency response as quite adequate only to move on to much more significant aspects of the analysis. If only we would do the same! There is indeed life beyond an RTA (although many here are quick to suggest that it is uninhabited!)

The article also actually explains quite allot about the parameters chosen, including the specification that the mid and upper frequency response corresponds to an isolated 13 mS of the sound arrival window (displayed in the ETC). I dare say that one not using a time domain measuring device such as TEF, EASERA, MLSSA or Smaart cannot isolate this window! Thus to compare a measurement taken strictly in the frequency domain with more limited frequency domain instrumentation does not address the 'same' event window and does not isolate the speaker from the more detrimental superposed room horizon...especially as we are dealing with what is essentially a delayed array system. May I also suggest that a greater understanding of the time windowing capabilities of time based equipment such as TEF (et al) as well as the restrictions Heyser placed upon the measurements due to the 1/8 corner loading described on page 65 and time offsets actually explain quite a bit.

I see nothing wrong with any of the measurements. The Nyquist, ETC and impulse displays are actually much more instructive than the frequency response curves which are actually of very little value and benefit when viewed in the total scheme of things. It is a shame that the real value of what Heyser was trying to show us (which is but a tip of the iceberg) is the part almost dismissed and subsequently ignored in favor of the least significant measurement. And it is a shame that we tend to dismiss what we do not understand and instead expect someone such as Heyser to cater to our lack of awareness rather than to expand our understanding to approach some of the insights that he chose to share!

I do not, nor do I expect anyone to understand everything. But may I suggest that our ignorance is not grounds to question the integrity of someone who quite literally possessed a much greater understanding of acoustical phenomena than any of us (to the degree that I am aware!).

dude,

what are you saying?

i hope that you are not implying that only you can grasp what heyser does. i admire his work quite a bit and became quite fascinated by his work (so did paul).

i only am trying account for the difference in freq responses because how you measure does make a difference (i do trust his measurements cause he earned it!!). if he did indeed (and try to remember this, i do not have the article) use tef or some time domain analysis, then it would make sense to me why the curves are different and knowing heyser and his work, i would bet that he did use tef.

Nyquist, ETC and impulse displays are instructive before the fact. if the designer knows this things up front then he can choose to improve the components and then use them to improve the system. to display these pieces of data after your done is like saying, i hate the color of the bricks on my house after the house has been built. by then, its too late.

roy delgado

Well, may I suggest you read the review. I have sometimes felt it to be an advantage to read it before debating it.

uh sorry....i am not debating the review. the discussion, i thought, was the freq response and then all the other "technical" plots were brought in on the premise that they were being ignored although, they were not pertinet with what john was discussing. all i asked from the review was, how was the speaker tested? kinda revelant don't you think?

As far as what is useful for design....OK....unfortunately the article by Heyser is a review. And reviews are typically done after a product is built. To fault reviews for not being done before the product is built would, I suspect, cause others a bit of concern.

again, you brought up the other plots not me. in a reveiw those plots can reveal just how well thought the designer did his work.

And Nyquist, etc. displays are quite useful to understand what is happening after something is built as well! Thus I suspect this may be why Heyser chose to employ them. I realize that I far out on a limb on this one, but that's my guess!

both heyer and keele, i believe, did these plots. we use to do them for spec sheets for our pro line. again to show that maybe someone has done their work or what was compromised in the design.

I also trust his measurement! That is exactly my point! But it seems some are more concerned that a review is done after the fact than with the allegation that Heyser "fabricated" and hence falsified results. Heyser mentions plenty of caveats, and qualifications for his methods. Does he explain them completely to the degree some would hope? Probably not. Do we need to guess whether he used a prototype of the TEF. Well, as he mentions he did, and many of the plots are watermarked "TEF", I suspect we needn't guess.

dude you are getting bent all out of shape for nothing. the responses are different; i know that heyser knows how to measure stuff; therefore, logic dictates that there is a logical reason why the responses are different, unless........i made up the curves (that's always possible). and the obvious escapes you......i don't have the article; that is why i am asking.....

My response was to John's allegation regarding the fabrication of the measurement (as I have quite enjoyed his other posts!) There are plenty of things to discuss in evidence (if one actually reads what Heyser wrote) without manufacturing crises based upon our ignore-ance of what information is provided.

One step at a time.

comprehension of what is being discussed is always good too.....maybe that should be the first step.....

roy delgado

[bodcaw boy]

Roy if your interested check your work e-mail for info on the Heyser Review.

For those wondering about the Khorn that was tested by Heyser it is in the Museum in Hope along with the Empty Cabinet used for the Cover Photo(The One Actually Tested was in a Walnut Finish. I had wondered for many years which networks was used/tested for the review and it was the AK-2.

mike tn[]

thanks miketn.

now i can read the article and see what else heyser made up.....[]

roy delgado

[bodcaw boy]

Mas-

No one is arguing about the context of the article beyond the amplitude response. The discussion is amplitude response.

Regarding the measurement method taken in Fig. 4, nothing above what I stated is said other than the distance the measurements were taken from. Nor am I discussing any of the other measuremets shown in the article. I am only discussing the amplitude response, nothing else.

There is no question that a very "significant" difference exists between Heyser's measurements that the anechoic measurements taken by Roy. That difference requires an explanation. If you see nothing unusual about the Heyser plot than so be it.

I have a different take on it.

jw

okay john,

back to the difference in the freq response (since he has now made me learn how to read all those plots!!), it semms to be that the difference is just that he had to "resort to computer software and physics". it looks like he just had a hard time measuring it. i remember that keele, use to use nearfield techniques to qualify the low end of a speaker.

this article has one of paul's favorite quotes (from one of paul's favorite people), "accurate percussive bass is a specialty which a properly setup corner horn seems to have to itself."

roy delgado

[mas]

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.