You're a native English speaker, I presume. What part of Pano's
post : " Argue the subject, which is technical, and keep away from
ad hominem posts. Those are the forum rules. Play by them." didn't
you understand ?
Flat earth too?
Joe, Steve, I just saw this thread for the first time today, and honestly, SY and Lojzek explained to you everything you need to know about this topic in the first few pages of this thread, a bit later supported by Scott and others.
Why go on? You are in a hole, not half way through a tunnel.
all due respect...i think turning Usher S-520 bookshelf speaker in an all active speaker is a more interesting project than new types of passive crossovers. I did a little math: using two chip amps good for max 50 watts, some 6 quality op amps ( OPA types) capacitors and metal film resistors , a 160 Va toroid and some Japan electrolytics is only about 40% more costly than hi quality passive crossovers but there is the power amp included and no need for fancy cables. So overall it is cheaper. And far more flexible
My old silver ashtray... it's embarrassing really.
OK, my friend. Run it past me then.
Either lives or dies, IMO. But let's discuss it. It's why we're here isn't it.
No more handwaving, Puhlease. I've nailed my colours to the mast often enough.
And while I know the rules, I often enjoy breaking them. That's creativity.
And while I know the rules, I often enjoy breaking them. That's creativity.
It really isn't. Being proud of it isn't good either.
That's up to him to out himself.
Well, you should prepare yourself to receive a nasty mail from my wife with complaint about me not getting anything done around the house, since I now will go into zombie mode in my search through all the threads trying to figure out who it can be
Cheers,
Mogens
SY, a flippin' funny post IMO. Whether ironic or sarcastic, IDK.Guys, you're trying to argue with MOZART.
I am a bit curious about a notable string theorist designing speakers, apart from myself, that is.
It's a curious fact that Professor Richard Feynman (who discovered the hugely accurate Q.E.D. theory) was a great buddy of the father of String Theory, Professor Leonard Susskind.
I've possibly given jan.didden a hard and uncomfortable time here, but I still want to know what his great speaker was. It could be good. In which case I'll promote it to Classic Monitors.
Hi Dan
This is a classic example of cherry picking, and they are very smart. The perfect current amp is no different from voltage source that can swing infinite volts and has an infinite output impedance - it sees its own output impedance before it sees any subsequent load. What effect will that have on its current phase angle? It will be zero, it will also be in the same loop, so the sum total phase current can only be zero Ohm phase angle as the sum of the loop elements. It has to return in the same state. It's not really brain surgery.
But what is interesting, is that the technique shows that the speaker is largely non-affected by the output Z of the amplifier, and that the phases that can be examined subsequent to those matching components (which are seen by the amplifier - which is what I was alluding to earlier but got caught up with other things), the filter elements that goes to the drivers sees the same thing whatever the original source Z. They will have the same slopes, so surprise, they will have the same phase shifts. I then see no conflict at all - just confected stuff, as usual. The fact that those filters/crossovers match, means that same thing is happening within each of those individual components.
Maybe I am not good at explaining the above to everybody's satisfaction (mission impossible). This has been vetted by others just as smart as they are. But cherry picking is what they do, as that suits their agenda - and why they have that I am not sure, but I think these are ripples caused by the original 'elephant in the room' and like a kangaroo caught in the headlights (something they won't understand), there is no escape.
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Can you translate this? It reads as gibberish. It might also help to be specific about what your reference is for the "phase" you're talking about.
System7,
I try to simply ask questions that make people think and hopefully some can answer with cogent answers that can cover a subject well. I do have the book by Esa on current drive of loudspeakers and believe me that leaves much to be discussed and questioned, especially about what he intends throughout the book about what he would actually change in the physical loudspeaker build to meet his requirements for a current driven device.
On the subject of the conjugate (tank circuit) again that would make a thinking person ask some questions. It seems simple enough to apply a conjugate network to counter the electrical parameters of the device itself but I will say that isn't exactly what it seems. The problem that I see is that those parameters are not fixed but shifting with the motion of the voicecoil in the majority of speakers. The inductance for one will change as the coil moves in the gap in a typical overhung voice coil situation and so there to will the capacitance and resistance, so how do you create the perfect conjugate network that is 100% effective through the entire excursion limit? So to say that you absorb 100% of the back emf seems to be counter to reality as most things are in speaker building and design. To my eyes you will still have some recirculating back emf to the amplifier and this must be controlled by the amp. These are the questions I ask, not just theoretical but practical in application. It is easy to design a perfect speaker and network in theory but then start testing and these premises start to fall apart. So who can say they know the effective result of a conjugate network with a common device, what percentage of leakage will there be as the values shift within the speaker, I surely don't know the answer to that one. I do know some who design these conjugate networks and do it well but I will add that the testing is done at very low power input to the device, 1 watt as is the usual test parameters, but I must say that this seems to be an incomplete and self deceptive set of results once we change the input power level.
I have nothing against improving the sound of a speaker and it is done all the time with improvements whether as simple as better network slopes or as complex as those who are now using convolution in their computer software to correct for many parameters including the room that the system functions in.
I am only asking for more scientific answers and real measurements backing up some claims or even a few simple measurements to show there are some real changes happening and not just self deception on many of our parts when we hope that what we have done is really doing something that we truly can hear. I have no motive to disrespect anyone here or any other thread, just questions that I would like to see answered.
I try to simply ask questions that make people think and hopefully some can answer with cogent answers that can cover a subject well. I do have the book by Esa on current drive of loudspeakers and believe me that leaves much to be discussed and questioned, especially about what he intends throughout the book about what he would actually change in the physical loudspeaker build to meet his requirements for a current driven device.
On the subject of the conjugate (tank circuit) again that would make a thinking person ask some questions. It seems simple enough to apply a conjugate network to counter the electrical parameters of the device itself but I will say that isn't exactly what it seems. The problem that I see is that those parameters are not fixed but shifting with the motion of the voicecoil in the majority of speakers. The inductance for one will change as the coil moves in the gap in a typical overhung voice coil situation and so there to will the capacitance and resistance, so how do you create the perfect conjugate network that is 100% effective through the entire excursion limit? So to say that you absorb 100% of the back emf seems to be counter to reality as most things are in speaker building and design. To my eyes you will still have some recirculating back emf to the amplifier and this must be controlled by the amp. These are the questions I ask, not just theoretical but practical in application. It is easy to design a perfect speaker and network in theory but then start testing and these premises start to fall apart. So who can say they know the effective result of a conjugate network with a common device, what percentage of leakage will there be as the values shift within the speaker, I surely don't know the answer to that one. I do know some who design these conjugate networks and do it well but I will add that the testing is done at very low power input to the device, 1 watt as is the usual test parameters, but I must say that this seems to be an incomplete and self deceptive set of results once we change the input power level.
I have nothing against improving the sound of a speaker and it is done all the time with improvements whether as simple as better network slopes or as complex as those who are now using convolution in their computer software to correct for many parameters including the room that the system functions in.
I am only asking for more scientific answers and real measurements backing up some claims or even a few simple measurements to show there are some real changes happening and not just self deception on many of our parts when we hope that what we have done is really doing something that we truly can hear. I have no motive to disrespect anyone here or any other thread, just questions that I would like to see answered.
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In some respects (including this one) 'roos are much like deer, with which those of us in the north are quite familiar. Herbivore, herds, harems, headlights, highway hazards, hopping over fences, hanging out in suburban yards. Maybe some other things that begin with H.
It would seem to me that an amplifier doesn't see an impedance until something is connected to it, whereupon it sees everything in circuit at the same time.
It would seem to me that an amplifier doesn't see an impedance until something is connected to it, whereupon it sees everything in circuit at the same time.
No.
If it gibberish to you, then maybe I have spared you.
Perhaps, but what you have spared me (and everyone else) is a coherent explanation of what you're trying to say, assuming there is a coherent explanation. If there isn't, you've answered the question- any explanation for nonsensical claims will necessarily be gibberish.
"Esa" quoted here several times is M.Sc. Esa Meriläinen, author of "Current-driving of Loudspeakers" His homepage Current-Drive - The Natural Way of Loudspeaker Operation
An interview here Shaking The Foundations Of The Audio Industry Esa Merilineno, Author Article By Zygmunt Jerzynski
An interview here Shaking The Foundations Of The Audio Industry Esa Merilineno, Author Article By Zygmunt Jerzynski
At one point I tried to clarify things for Joe; Joe is this what you mean? A picture and 1000 words and such?
OK, went and simulated such a situation. A voltage source driving a reactive network, versus a current source driving the same reactive network.
Graphs show voltage across the network (left axis) and current through the network (right axis).
Top with a 1V, 1kHz V-source. As predicted by theory, the current leads the voltage because of the C.
Now I changed the V-source to an I source, with the same amplitude as the current that I saw in the voltage drive case, which happened to be 161mA.
The result - exactly the same! This current generates the same 1V amplitude across the network as in the first case. Phase shifts are the same in magnitude and relation.
Only difference is the start of the zero crossing of the generator, which is (of course) voltage in the 1st case and current in the 2nd case.
So unless this is NOT what Joe means, it appears to me that the reason he has issues to explain what he means is that what he thinks how it works, is wrong.
Jan
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