gedlee said:
I don't think that there is a room for suggestion in such a comparison but perhaps I'm wrong?
gedlee said:
oh I didn't know!
Linkwitz recommends Etymotics ER-4s as well, but with equalizer, the Shures don't need equalisation in his opinion
according to manufacturer E2c employ a "Dynamic MicroDriver" as opposed to "Balanced Armature Driver" but I haven't got a clue about what it is and what it implies
best,
graaf
ucla88 said:
Mark,
Your couple of posts pretty much sum up what I think when reading this thread. I don't see much new to learn from other posts. In fact, as we know, the new concept and measure of nonlinear distortions Geddes and Lee proposed are not new to us. We've all known a traditional single number of distortion level does not mean much. And thanks to you, Zaph, and some other excellent people's contribution, many of us know how to interpret raw distortion measurements and how to use the information in designing loudspeakers.
I understand what Gedlee meant by saying the following. But it IS too bold a statement and can be misleading to people who have limited knowledge:
Jay_WJ said:
I don't think that you are being fair here. "We've all known ...", if that were true then why was there so much interest when we presented our work. And I would certainly appreciate any references to this information that "we all knew". People had talked about THD and how it was suspect and they talked about changing the way we use the harmonic information, but nobody prior to us had done the work to prove this. Again, if I am wrong here, then give me some references.
If my statements mislead those with "limited knowledge" then I am sorry - educating them is what I am trying to do here. And I will tell you with absolute certainty that the majority of people out there still believe that THD is the answer.
I suppose you know all this, but please, there are others out there not so smart who would like to learn about it.
454Casull said:
THD is meaningless and nonlinearity is not as important as its claimed to be. Nonlinearity can be made to be unimportant by proper system design. But a poor system design can have enough nonlinearity that it is an audible factor, but THD or IMD won't tell you if it is or isn't.
gedlee said:
I admit that your "we" and my "we" can be different.
My "we" were limited to people I talked about in the context of my above particular post.And I didn't mean to undermine your work. Your work is a better, formal instantiation of what some experienced people have known and used. I'm a cognitive scientist. People were very interested when the concept of short-term vs long-term memory was first domonstrated by experimental and modeling work. But many people before had such a concept.
Having a hypothesis and proving it are vastly different things, don't you agree? The hypothesis part is easy - proving it is where the work is. Most people stop at the hypothesis and just assume its proven because they thought of it.
I had guessed that your "we" was some exclusive group and I thought that was a bit unfair to bring up that way.
Everybody in audio already knows everything anyways, so there's not much point in claiming membership in that club.
I had guessed that your "we" was some exclusive group and I thought that was a bit unfair to bring up that way.
Everybody in audio already knows everything anyways, so there's not much point in claiming membership in that club.
gedlee said:
I agree. But a bit reluctant to agree with the "proving" and "vastly" parts. As scientists, we know that there is no real "proof" in empirical sciences. We only test hypotheses by theorizing and experimenting. Strictly speaking, the result is not like "proof." I use the word proof only in logics and math.
Having a hypothesis and proving it are vastly different things, don't you agree? The hypothesis part is easy - proving it is where the work is. Most people stop at the hypothesis and just assume its proven because they thought of it.
I totally agree. Excellent paper BTW.
I have to constantly do battle with subjective vrs objective in my field. I truly doubt that ppl would get on an airplane or cross a bridge or such if they believed that a final decision as to the use of a product was based on " i think its OK".
ron
(the hardest thing you can do is to make something simple)
I totally agree. Excellent paper BTW.
I have to constantly do battle with subjective vrs objective in my field. I truly doubt that ppl would get on an airplane or cross a bridge or such if they believed that a final decision as to the use of a product was based on " i think its OK".
ron
(the hardest thing you can do is to make something simple)
Jay_WJ said:
An excellent point. I will try and reserve "proof" for math. I certainly know what you are saying and you are right. The data strongly suggests our hypothesis was correct.
I once read a paper from the Defense Department on a Risk Assesment. I was very impressed by the preciseness of the language and how well they defined the terms used. In our business, at best, people only have a vague idea of what the other guy means by his terms. Precisness is reserved for name calling.
Jay_WJ said:
Jay_WJ said:
Hi Jay,
I think that there are some of us doing hopefully meaningful distortion measurement for the diy community. I have seen some posters take Dr. Geddes out of context to justify their high distortion system. Look at the kind of systems Dr. Geddes is talking about-large woofers, subwoofers, compression drivers. All of these systems will have very low nonlinear distortion and thus arguing about which is better on the basis of an arbitrary number has dubious merit. To paraphrase somewhat Dr. Geddes has said is that in a well engineered system, THD distortion isn't important. The key is, what is a well engineered system? Is that a 5" woofer connected to a short ribbon with a lower order crossover...
Measurements like mine do show higher order products and I've always stressed that these are much more important than lower order ones. Unfortunately, THD is generally dominated by the second or third order products and so of much less utility. I don't think I've ever even bothered with a THD measurement.
And audiophiles are not immune to focusing on the wrong distortion measurements even if they've looked at my or Zaph's site. I've seen it posted on more than one occasion that the xt19/25 ring radiators suffer from "too much" second order distortion. The xt series would have a highish THD. But in fact, is an excellent low distortion driver where it counts. (setting aside the other oddball directivity issues the xt has.)
Old link, has some errors I would rewrite, but useful info
As an aside at times, Dr. Geddes literary style is a tad abrasive/defensive (sorry Dr. Geddes). This seems to cause a bit of consternation
ucla88 said:As an aside at times, Dr. Geddes literary style is a tad abrasive/defensive (sorry Dr. Geddes). This seems to cause a bit of consternation
No offense taken. A polite critique like this is always welcome.
But don't underestimate the power of "shooting the messenger". I don't tell people what they want to hear.
As scientists, we know that there is no real "proof" in empirical sciences. We only test hypotheses by theorizing and experimenting. Strictly speaking, the result is not like "proof." I use the word proof only in logics and math.
I am not a scientist. I am an engineer, we make things work, we dont theorize, just solve the question of how to make it work.
ron
(doing the impossible only takes more money and time)
I am not a scientist. I am an engineer, we make things work, we dont theorize, just solve the question of how to make it work.
ron
(doing the impossible only takes more money and time)