Keantoken,
Your red trace is not correct..that doesn't happen.
Go to single frequency, and expand scale to two cycles visible. Show exactly where in the current waveform the eddy dissipation occurs.
Given current, or acceleration, we can integrate to get velocity, and again to get distance...then we can see exactly where the entities you've calculated come into play.
jn
Your red trace is not correct..that doesn't happen.
Go to single frequency, and expand scale to two cycles visible. Show exactly where in the current waveform the eddy dissipation occurs.
Given current, or acceleration, we can integrate to get velocity, and again to get distance...then we can see exactly where the entities you've calculated come into play.
jn
Play all you want guys! Now when it comes to loudspeakers, what do you use at home, JN? Come on, show us. I showed you mine.
Now when it comes to new ideas, unfortunately it is you guys who will not accept new knowledge.
Now, I would like a serious recommendation of advanced loudspeaker driver design in the form of a book or a series of technical articles. Anyone have any suggestions? I tried a few years ago to buy some books on the topic, and found them woefully lacking in intellectual content. Little or no physics, imagine that! However I usually buy a book a week or so, and I would love to order and read something that would put me up-to-date.
Now when it comes to new ideas, unfortunately it is you guys who will not accept new knowledge.
Now, I would like a serious recommendation of advanced loudspeaker driver design in the form of a book or a series of technical articles. Anyone have any suggestions? I tried a few years ago to buy some books on the topic, and found them woefully lacking in intellectual content. Little or no physics, imagine that! However I usually buy a book a week or so, and I would love to order and read something that would put me up-to-date.
So, you are reduced to ""my speaker is bigger than yours""?? Are you in the third grade?? Seriously?
Why not talk about what you've accomplished in this century. 18 years, you should have something to show for it, no??
You mean, like bybees?? Really?
pssst, john....pay attention here....
THAT'S WHAT I'VE BEEN SAYING ALL ALONG!!!
The "books" you are spouting are, what did YOU call them.."woefully lacking in intellectual content".. Well, DUH!! Get with the program..
Then sit back and follow along with what we are doing. Not only will you learn how to advance SOTA, you could actually be part of the group doing it. Instead of sitting on the sidelines tossing marshmallows in our direction.
John, just ask questions, don't be shy..
jn
Books are usually published by academic types who need to publish research to get promoted at work. Most modern speaker driver improvements may be proprietary where people need to keep quiet about it to avoid getting fired at work.
The lack of useful books probably doesn't mean development of speaker motors has reached the end of the line. Highly unlikely. JN is right that old models you refer to where simplified. Klippel's work may seem very advanced to some audio designers, but some of it is really is just the application of various approaches taken from modern control theory. Klippel tried a few until he found some combination he thought worked pretty well. Its good that he did but, it's not about fixing underlying problems such as JN is trying to do.
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Markw4, you are a smart guy. Should I just read Klippel? What speaker driver designs have you found or heard about that are extra special? Most here, closely following JN, appear to lack the BASICS as to how a loudspeaker driver actually works, so all they can do is blindly follow. This is what I am trying to point out.
Now, what have I done lately? Well, I have worked for five separate companies on various electronic designs, including preamps, power amps, phono stages, etc. since the year 2000 They seem to get A ratings when they come out. What about you JN? Where have you moved physics in a new direction? Come on, just give us a hint. '-)
John, come on now, you know JN has chosen to remain anonymous. Me too for that matter. People who prefer to retain a level of privacy should be able to do that without having to be argued into outing themselves.
Also, I know people who work at the cutting edge in academia, write book chapters, etc. What JN is has been saying is not out of line for people who do that type of thing. They get pretty good at estimating if they will be able to pull off something that hasn't been done before, but there is always a risk of failure doing that. However, people who don't maintain a good track record don't stay around long.
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Boloney, Markw4. JN hides his identity so he can throw more 'rocks'. I looked him up at the company he works at. He is a darn good coil winder. You, Markw4 have done some service to industry (medical) as well. Privacy has nothing to do with this. We 'know' that he doesn't invest in audio, he just talks here about it.
My loudspeakers ARE bigger than yours!!!
"FEA" analysis of the magnetic structures and the rest of the structure is old hat and the specifics of the modeling are rarely disclosed. Also not surprising is that small signal and large signal results differ. Some of the modern loudspeakers are designed to have a rising output with increasing frequency as would be expected of a piston moving a constant distance with increasing frequency.
So let the magnet structure disscusion continue in peace. The blind men examing an elephant does come to mind. So keeping in mind the motor structure a part of a transducer, albeit an important one, does serve a purpose.
Or we could continue to argue about whose er ego is bigger.
"FEA" analysis of the magnetic structures and the rest of the structure is old hat and the specifics of the modeling are rarely disclosed. Also not surprising is that small signal and large signal results differ. Some of the modern loudspeakers are designed to have a rising output with increasing frequency as would be expected of a piston moving a constant distance with increasing frequency.
So let the magnet structure disscusion continue in peace. The blind men examing an elephant does come to mind. So keeping in mind the motor structure a part of a transducer, albeit an important one, does serve a purpose.
Or we could continue to argue about whose er ego is bigger.
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So JC, what are you contributing to the discussion on speakers? Throwing insults doesn't help anyone. Also calling one of the major US research labs a 'company' is doing a disservice to them. One might think you are just trying to start an argument?
Good catch, it was a problem in my eddy loss model. It was giving the eddies zero resistance at frequencies where the skin depth is larger than the part. I was wondering why I could never get 3rd harmonics, it's because velocity eddies were getting a DC bias and the zero crossings are what cause the odd harmonics.
From top to bottom:
Cone force
Reluctance force
Eddy force
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Really? I don't know, and I don't know if you know with any certainty.
In any case, we are talking about coil winding here and some things very closely related to that. I would suggest taking a wait-see attitude and hope something good comes out of it. If you guys would stop arguing it might help. Somebody has the be the bigger person and stop first.
John this is totally out of line, you do yourself a disservice by posting this stuff.
John -- JN's identity is terribly hidden if you spend a millisecond tracing what he's shared so far and a well aimed google search. Less time than you complaining.
Richard Marsh worked in just as famous a research laboratory, LLL here in CA. Is JN polite to him? Now when it comes to speaker size, the Sequerra Met7 is pretty small, AND it is my favorite. How can this be?
When it comes to speaker design, I must admit that I don't do that anymore, but "It is better to be a 'has-been' than a 'never-was'". I did pursue loudspeaker design at the highest levels, selected the worlds' best drivers and everything, but I found that I was not very good at it, so I befriended famous loudspeaker designers and they gave me samples of the efforts, in return for my circuit designs for them. No, I did not pay for the loudspeakers that I have now.
IF I had to buy a loudspeaker, I would choose something like what Richard Marsh selected. It is a horn/direct radiator using the latest designs. YES, they improved the horn driver, and it is better than what we had to live with 45 years ago from the same company, and we ultimately rejected for the GD. John Meyer has made something similar that might be pretty darn good as well. I worked alongside John Meyer, when we made a 3 amp driven all horn design with delay line, etc. for over 1 year back in the old days. John Meyer is a brilliant speaker designer, but his effort is focused on MEASURABLE improvements, (kind of like PMA), not subtle sound differences, so we parted company decades ago, but he is still a great speaker designer.
When it comes to speaker design, I must admit that I don't do that anymore, but "It is better to be a 'has-been' than a 'never-was'". I did pursue loudspeaker design at the highest levels, selected the worlds' best drivers and everything, but I found that I was not very good at it, so I befriended famous loudspeaker designers and they gave me samples of the efforts, in return for my circuit designs for them. No, I did not pay for the loudspeakers that I have now.
IF I had to buy a loudspeaker, I would choose something like what Richard Marsh selected. It is a horn/direct radiator using the latest designs. YES, they improved the horn driver, and it is better than what we had to live with 45 years ago from the same company, and we ultimately rejected for the GD. John Meyer has made something similar that might be pretty darn good as well. I worked alongside John Meyer, when we made a 3 amp driven all horn design with delay line, etc. for over 1 year back in the old days. John Meyer is a brilliant speaker designer, but his effort is focused on MEASURABLE improvements, (kind of like PMA), not subtle sound differences, so we parted company decades ago, but he is still a great speaker designer.
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Well it's good to hear that there have been real improvements in driver design in the last 45 years, and even better that the improvements are measurable. Has Mr. Meyer detailed these improvements in a book we could read?
Funny thing is that in a blind test between JBL M2 and Revel Salon 2 the Revel was preferred.
Guys! JN can be found at the Asylum. His full name is there. Then you can see technical progress reports from places he has worked at with a little google'ing. No big deal. Go and look before he sees this and tries to clean it from AA. He probably forgot his name is there.
JBL M2 are powered by Crown sound reinforcement switching amplifiers with some DSP for cross-overs, frequency response flattening, and protection limits. They would probably sound better with better amplifiers and better dacs after the DSP.
Actually, I find that quite a few here are actually well versed in the topic. We all have slightly different specialties, but that diversity is very very important when dealing with a multidisciplinary topic such as speakers. As would be your valued expertise should you decide to engage the discussion.
The list is long. However, always remember that my role is to design, built, wire and test new hardware. Many times, that requires I make advances in the SOTA. My winders, made 25 years ago, are unfortunately still beyond SOTA. I say unfortunately, because the tech can be used to advance medical accelerators for cancer treatments, and to transfer that knowledge to industry require money, money, and money...did I mention money?
Some of the hardware is very very large, some is very small, and for much, there are no books..uncharted territory.
As such, I am typically called in to fix stuff that doesn't work as expected. And normally, that is when multiple technologies are involved, like magnetics, coils, motors, cryogens, ground loops half a mile around..
My current work is motion control for wigglers and undulators, big beastly things that weigh tons and require positioning accuracies in the 20 nanometer range. They are used to create x-Ray beams, and over half the users are biological and medical. They do the type of work that can also assist in cancer breakthroughs, so I want to do my best. Too late for some, but towards the future.
Oddly enough, coil winding is a very small part, but thanks for that accolade.
And we are actually talking about coil winding.
I do find it odd that I have to "invest" in audio in order to be allowed to contribute my expertise to a technology that you also claim is "lacking intellectually".
Yep, always have been.
JC, I hope you will engage the discussion, I do value your expertise.
Jn
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