No, e/m is not the only thing, I've noted that prior. I've several other techs as well.
As to designing audio circuits, you are absolutely correct. And, that is what I would like to see from you. Not hooey about pics in freezers, not near superconducting garbage, actual circuits and understandings.
We all have our own talents, yours is not shilling for hucksters, it is something far better.
Jn
If I were to build a dual vc, I would do it in my basement. (I do not have a garage).
I would purchase two gauges of copper magnet wire from msw, I would use the west system type 105 resin with the tropical hardener because I'm not exactly fast, I would use some unidirectional weave graphite from that hobby store for rf planes (tower hobbies I think), and I would make my own winding mandrel on my lathe. I can do roughly one thousandth of an inch runout on the lathe.
I would wet wind as I do not have a pump to do vacuum impregnation at home.
All this is easily doable on a shoestring. Even a split mandrel, or one made of Teflon purchased from McMaster Carr (if you want to be impressed, buy something from them. How they get the product to your door by EOB the day after you order is not believable. Sorry to those outside the us.
The biggest resource to me anyway, is the people. I do not make personal thinks at my employ. That is what a basement is for.
Ps. Oh, I would also carefully gut the eminence sigma pro 18 in my basement gathering dust if I so desired. A proof of principal does not need hi temp epoxy, it just has to survive long enough to get data.
Jn
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No, where I work does not make me academically gifted. The people I work with are that. Some people here are that.
I am good because I have no problem asking others for their expertise, and using it..
Best of luck with your wife.
Jn
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That's why I said round wire only, it is a trade off.
And as I noted, this is basement only. My budget is very limited.
Jn
He's acutally a cross between B.A from A-team and macgyver but with a bigger budget 😛
There is a lot of history here. some on here have known each other for 40 years from pre-internet days. There is a cycle with some of these discussions which is akin to trench warfare. In some cases there almost seems to be cut and paste from the previous fracas. some of these cycles have been running 10 years on this forum. As such there is a degree of 'oh no not again' that you might miss. But if someone repeatable spouts nonsense then they should be corrected. If they are offending by being told that they are wrong that it not the fault of the corrector (IMO). Then it all gets out of hand. In a bad cycle threads get locked.
Sorry to hear that, hope all goes well.
Many of us would like that, however in 10 years here it hasn't happened. certain people I fear do not want to move to a common understand OR progress things.
Nonsense. We are simply pointing out his confusion and mistakes in basic circuitry. Do you support his confusion? I thought you were better informed than that. Or is this just an unthinking knee-jerk reaction in support of anyone who says anything out of the ordinary?
Anyone can pick up a textbook. This is necessary, but it is not sufficient; unfortunately, you also have to read and understand the textbook. Some people don't bother to read; others read but don't understand. Some of them can then believe that their confusion is some sort of more advanced knowledge. Language is vital; online it is about all we have to convey ideas. You are not extending language, just as you are not extending knowledge; you are merely exhibiting a failure to understand textbooks. We are not threatened by this, but your defensive comments suggest that you feel threatened. JC's 'support' suggests that he thinks you a feel threatened.
Comparing yourself and your ramblings to a giant of quantum theory is quite funny. This sort of delusion seems quite common among those who claim to advance the art of audio by ignoring physics.
You are. The fact that you do not realise this merely demonstrates the lack of understanding you have.
Real science starts with understanding existing knowledge, and then advancing it. Quack science starts with rejecting existing knowledge, and then replacing it. Someone not educated in science could get these two quite different things confused.
More confusion.
Confusion.
No.
Yes, you have given up control from the amplifier. The speaker itself now has to do all the control. Is that really a step forward? In the example you show, it looks like the electrical part of the bass damping has to be provided by the series LCR circuit in the crossover, so you are effectively using a DF around 1 which would require extra mechanical damping in order to avoid a bass boost.
Harrison was just nuts. He was a carpenter, he developed the gridiron temperature compensation scheme, IIRC, he developed the cycloidal cheeks to compensate circular error, he may have even developed the grasshopper escapement. And he refused the prize for H1, H2, and H3, only accepting it for H5.
Incredible works of brass (they are at the observatory in Greenwich and are amazing.)
Jn
😀😀
My kitchen table has a grandmother strike and chime movement on it partially disassembled for repair, and a cuckoo next in line.
I never knew Loctite came in many different favors. I am using purple for the 2.5mm screws.
Jn
Thanks for your considered post. It puts things into perspective, and as such I would like to suggest that you don't take things here too seriously. It's just a thought. All the best 🙂
Is this more creative language extension? We troll; we cannot troll; all in the same sentence.Joe Rasmussen said:
I thought all trolls are a minority?
You came here presumably to enlighten us with your new ideas and now feel hurt that we reject them on the grounds that some are incoherent (so we don't actually know what you are saying, although we suspect that you don't know what you are saying either) and some are simply wrong. To the extent that your speakers actually work (although data on this is quite thin) they don't work in the way in which you think they work.
No, technical error is not taboo here; it is commonplace. However, error is error and one of the strengths of this forum is that error will be corrected. The person propagating the error may find this disconcerting. I have sometimes been that person and I know it is not a comfortable place to be, but it is a helpful place to be for those who learn from it as I have.
That was not an assertion; it was a statement of accepted truth. Whether he minds you disagreeing with it is neither here nor there; the issue is that you are disagreeing with something which is true i.e. not a matter of opinion. Disagreeing with truth is not a good way to do engineering.
There seems to be a lot of amateur psychology breaking out all over DIYaudio at present. It puzzles me why JC is so keen to demean himself by making such silly statements.john curl said:
And it will make no difference at all if the speaker is fed from a voltage source. The reason it will make no difference is that it cannot make a difference; if it seems to make a difference then it is not being fed from a voltage source. What has this got to do with anything?Joe Rasmussen said:
Characteristic impedance at what frequency? In the audio band, cable characteristic impedance is not resistive and changes with frequency. Terminating at the RF characteristic impedance (which is resistive and fairly constant with frequency) may help reduce RFI and maintain amplifier stability in marginal cases; it certainly won't do anything to the speaker itself.Max Headroom said:
No. It cannot change in any way. This is your fundamental misconception. It puzzles me that you persist in promoting this newbie-level error as though it is some new deep insight into speaker behaviour. The speaker sees a voltage source, whatever impedance you put across the voltage source terminals. If the speaker sees any difference then it isn't a voltage source. It really is as simple as that. Talk of back-EMF etc. is merely blowing smoke (into your own eyes, as much as others' eyes, it seems).Joe Rasmussen said:
There are other people out there who are equally confused by basic circuit theory? Yes, I guess there are. Anyway, I have just put this one to bed, so no patience is needed. If you don't believe me, ask jn or Scott.
I have a fear of using the wrong loctite ever since I used studlock by mistake on something. Heck, they were both in red bottles with numbers on!
Space qual stuff I remember was particularly strong. very much 'ain't ever moving again'. I am sure there is equally interesting mixes for holding studs into unobtanium?
Space qual stuff I remember was particularly strong. very much 'ain't ever moving again'. I am sure there is equally interesting mixes for holding studs into unobtanium?
Jim Williams was particularly fond of chronometers, he had one brass one very early from the UK and one from the Naval Research Station that was about 4' tall and had weights made of platinum. He said it did 1ppm, I have no idea how he got it. I don't think many have seen his collection and have no idea what happened to it.
Hey JN, it is us 'nuts' that make progress that is lasting. What have you done, specifically, over the years? Now don't take credit for your peer's work, it doesn't count. They may be on the way to a Nobel Prize, but I doubt that you are. However, you are both an accomplished clock repairer and a coil winder as well. When I need a coil, hopefully I can come to you for advice. Seriously
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Characteristic impedance means by convention at RF, but of course you knew that already.
Terminating each end of the speaker line quenches RF pickup and RF ingress into the output port/NFB sensing port of the amplifier.
This removes a veil of low level noise, you should try it, 0.6W MF is good enough for the experiment.
Dan.
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You may also calculate a "characteristic impedance" on LF, which would be sqrt(R/G). It gives interesting numbers and interesting transition curve from LF to HF.
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