I waded through the paper to the point that it seems to be about commercial recording microphones more than measurement mikes. Even then I'm not sure it brings much useful to the table. B&K discusses bootstrapped mike preamps and clearly its possible to get 20G equivalent impedance across most of the band. Some potential for peaking at high frequencies with small (1/4") capsules is mentioned.
Joe's Earthworks is a good microphone. The early ones used selected Panasonic capsules. I'm not sure who the current vendor is since Panasonic left the business. The Earthworks guys told be that they found the Microtech-Gefell MK301 was the best reference microphone for extended response, at least using their spark discharge test.
The graph that shows the relationship between capsule capacitance and impedance:
(source: Holger Pastillé;Electrically Manifested Distortions of Condenser Microphones in Audio Frequency Circuits, J.AudioEng.Soc., Vol.48, No.6, 2000June, 562)
IIRC we've discussed the distortion topic quite intensively already in January 2019 and the relevant publications were quoted/posted/linked.
This article by Pastillé was later part of his PhD Thesis (unfortunately available only in german) which I've most likely linked to also in Januar.
(source: Holger Pastillé;Electrically Manifested Distortions of Condenser Microphones in Audio Frequency Circuits, J.AudioEng.Soc., Vol.48, No.6, 2000June, 562)
IIRC we've discussed the distortion topic quite intensively already in January 2019 and the relevant publications were quoted/posted/linked.
This article by Pastillé was later part of his PhD Thesis (unfortunately available only in german) which I've most likely linked to also in Januar.
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Terry, I say that Large BQP's have effect, is that crazy ?.
Joe, I don't consider you crazy buy you do confuse understanding of your arguments and findings by 'unconventional' terminology.
You're Elsinores are getting good reviews but I read this comment
Any ideas of what he means, is it needed to fine adjust compensation network values ?.
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I think buy should be but?
I think you are a bit more out there than me and some characterise me similarly when I am actually quite conservative. It's being creative that they don't understand. And I want you to be crazy.
You know we call the English Pommie Bastards, it is Aussie slang term of endearment, right? We are all a bit crazy in my book. 😀
The comment:
Dan, he sounds a bit contradictory?
I am not sure where in the room he was, very heavy drapes down the side of the hall and carpeted, soft seats, as I remember it. As you walked towards the back it got progressively darker sounding. The guy who was assisting me happily had some 12" stands to put under the Elsinores and that saved the day, but you needed to seat in the first four rows. Maybe could have used another 6" in height.
But it got a tremendous reception and as these things can be so hit and miss, I was very pleased it went so well. I got a number of calls in the days after, made some friends down there.
Next week will be involved in the Sydney Audio Club (SAC) demonstration, my part will be the electronics and the Elsinores will not be there. All are welcome, who can make it, 2PM Sunday 18th, Epping - next to the Epping Aquatic Club.
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Now for something amusing?
Mr. Vacuphile,
I DO NOT REMEMBER SAYING THAT?
That first quote would not be expected from an honest man who, according to the site linked to by Scott, fills his pockets with another man's 2.500 $ to fill that other man's Oppo with crappola. Nothing fun, nothing DIY, just spreading bogus stories and preying on the gullible for personal financial gain.
(Emoji for barf bag)
And yes, it bothers me when this happens under my eyes.
Yes, typo.
I am probably the most conservative of all actually in that I work from first principles as you are doing. I also like to prove things as you have done, I do not assume anything and I do not believe everything that is stated especially in the audio world. Those without experience of for example Large BQP just repeat what they have been told....the blind leading the blind as it were but this group of non experienced/non believers forcefully attack those with real world subjective findings, this is not logical and to me an example of why it can be useful to question 'collective wisdom' just as you have done. As Heyser said: "If any 2 people can hear a difference, then it is real!"
I'm not sure what he means, that's why I am asking.
Ok, overly big and overly damped room, not really representative of domestic environment.
Good.
Good luck with it.
Joe is offering a service and his customers are saying that they like his work, it looks like $2.5k is good value to them when compared to 'big name' offerings. You seek to denigrate and defame Joe, just what the hell is your problem ?.
Dan.
'Calling one out' should be based on undisputable facts, but did you consider that maybe you've simply misunderstood Joe Rasmussen's comment?
The paragraph that you've quoted says just (IMO of course, as it is always likely to misunderstand something in a foreign language), that he don't understand _your_ comments wrt 'the Oppo case' while your interpretation is totally different.
You've written in the post to which he responded:
".... All that Oppo-mod nonsense seems to be over, so time for something new.
Edit: you asked for my definition of nonsense, but it cannot be defined, only understood; the Oppo thread was mentioned by means of example."
and Joe Rasmussen responded with:
"The Oppo comments makes no sense to me either. To complain about it is same as complaining about DIY or about having fun. Particularly odd considering it is on a DIY website. I don't agree with everything there either, but I don't allow it to bother me, may I suggest adopting a similar stance? Just saying."
(bold feature activated by me)
which seems to me as if he was saying that your (vacuphile's) 'Oppo comments' don't make sense, as it is just diying or having fun....
and your interpretation of his response:
" I remember Joe stating forcefully that he had nothing to do with that Oppo modding nonsense. .."
which doesn't seem to fit.
Yes and from what I see you are deliberately and maliciously denigrating and defaming Joe, and you provide no proofs for 'calling him out'. So what specifically is your issue with what Joe is doing , generalisations don't cut it, you need to describe precisely what is wrong with designing, constructing and fitting custom pcb's as an improvement/upgrade service as Joe is doing or is there something else that you wish to make issue with ?.
Dan.
If you were passing a hat around in order to collect some money I guess you would call a few shirt buttons a contribution?john curl said:
If so it is unfortunate that he mainly seems to share his crazy ideas with us here. For many of us this is the only time we have come across him (and everyone else on here) so we only have what he says here to respond to. Many of the people on here have had successful careers in various technical industries or academia, but if they spout nonsense here they will be corrected. The wise ones will learn from this, as I have, and be thankful.Terry Demol said:
Before I arrived here I had no idea just how profound were some of the knowledge holes in people working in the audio business. I was quite shocked at first; now I am used to it and regard persistent nonsense as a flag that someone may be in the business.
Could you give us a clue as to what that sentence might mean? The amplifier produces a voltage and the load takes whatever current it will. In what sense is the amplifier "producing reactive current"?Joe Rasmussen said:
I think that any discussion with him is hopeless, he does not understand even very basics of electrical circuits. Probably this is the key of success in "HighEnd" audio.
You are right, the load takes whatever current it will. So I am speaking of when it deviates from a zero current phase angle.
See attachment, here the speaker is drawing the same current at all frequencies, the Yellow (CH1) is the voltage of the amplifier, and the Pink (CH2) is the current of the amplifier. It is a 2KHz square wave and yes, it is a 'measurement' - hurrah! 🙂
BTW, there is nothing wrong with 'crazy' ideas if they lead to something, it does not necessarily mean the person is crazy, but rather that he is capable of creative thinking that has possibilities that might not otherwise have been contemplated.
I am sure that the Wright brothers were accused of being crazy by someone and so too Glenn Curtiss. Only a crazy person would say it was possible to fly, right?
There are people around who are far more 'crazy' than me. I am actually in the 'tame crazy' category. More like a friendly cuddly one. 😀
Attachments
This is the crux of the problems, Joe this is what I meant by your use of 'unconventional' terminology that does not make sense. What you mean is harmonic currents, or circulating currents which means energy that is stored in the load returning to the source of the energy due to load end reactances. I could not understand WTF you were talking about one phone conversation and I tried to tell you that an amplifier 'producing reactive current' is not a term that makes any sense and such misunderstanding is the source of the communication problems and your persecution. I then tried to explain to you that you mean harmonic currents which is a standard term in AC theory, radio theory and power distribution theory.....I must say that I question your training in and understanding of AC theory.
Joe, this impedance equalisation really is just application of AC theory and optimising the system, the same as is done on radio systems and electrical power distribution systems to provide maximally efficient power transfer from generator to load. There is no need for BS/confusion terms like 'amplifier producing reactive current' and there is no need for BS/confusion terms like 'back EMF impedance' when you mean resistance (or impedance) in series with driver back EMF. A loudspeaker with impedance equalisation presenting as clean resistive load means that there is no reflected energy and this lack of return energy is what brings the subjective benefits and by several concurrent means.
All you need to do is describe your Elsinore speakers as being impedance equalised which means they present as clean resistive load which all amplifiers will perform their best with. The technically astute will understand that amplifier output resistance and cable resistance will serve to attenuate loudspeaker output level but not alter loudspeaker frequency response and are therefore relatively irrelevant. Joe, this loudspeaker impedance equalisation is nothing new but it is relatively rare principally because of cost of components and cost of implementation. Joe, what you are doing is good, very good, especially in the tube amplifier world and is required for optimal sound reproduction but it is not 'crazy' and it is not groundbreaking, just sayin'. All the rest of you can stop bashing Joe from now on, to do so actually indicates that the aggressor does not understand AC theory.
Dan.
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OK, so you actually mean a reactive load. Why not say so? Reactive loads are quite normal for audio. Amps differ in how well they cope with them when near maximum output.Joe Rasmussen said:
Is the speaker approximately resistive, or the speaker plus some network you have put in parallel with it? If the latter, you have no idea what current the speaker is drawing. It may be a 'measurement', but what is it measuring?
Thus far your ideas have not led to anything. We either find that you mean something different from what you say, or we find that you are mistaken and confused about basic electronics.
Now all I can think of is the Carl Sagan quote about how "they laughed at the Wright Brothers..."
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