Mbrennwa is just plain right.
Current only matters into the driver coil, and that's obvious to any technically educated person.
I also see no controversy on this, and reasoning behind it has already been cristal-clear explained into this thread.
I'm sorry for being rude, but whoever does hold on the idea of the voltage being what is making the sound from a driver, is simply...
1/not aware of some elementary laws of electricity, and
2/not doing a favor to himself for not trying to understand why it is so obvious to sufficiently knowledged people.
Let's move on from this void discussion guys, and focus on sharing about other (better) concerns.
Kal
Current only matters into the driver coil, and that's obvious to any technically educated person.
I also see no controversy on this, and reasoning behind it has already been cristal-clear explained into this thread.
I'm sorry for being rude, but whoever does hold on the idea of the voltage being what is making the sound from a driver, is simply...
1/not aware of some elementary laws of electricity, and
2/not doing a favor to himself for not trying to understand why it is so obvious to sufficiently knowledged people.
Let's move on from this void discussion guys, and focus on sharing about other (better) concerns.
Kal
I am not smart enough to follow all the arguments here, but I’m curious: What are the implications of this idea that what we are listening to is the current? Assuming that’s true, how do we benefit from that idea? How are our audio components changed to improve the quality of our listening experience? How is that experience changed?
The voice coil is driven by current. With a voltage amp the spaekaer impedance (flat-right?) acts as teh R in a voltage to current conversation.
With a current amp the voice coil is driven directly.
With a voltage amp the speaker impedance does not affect the frequency response.
With a current amp (or even a high Rout volatge amp) the speaker (a portion of) impedance is imposed on the frequency response.
Compromises.
dave
With a current amp the voice coil is driven directly.
With a voltage amp the speaker impedance does not affect the frequency response.
With a current amp (or even a high Rout volatge amp) the speaker (a portion of) impedance is imposed on the frequency response.
Compromises.
dave
Yes, I will and it will be on my (and our) terms.
It's a good think that I am not alone.
You are right, stating the obvious like the "Lorentz force" should not be controversial. And yet you say "I still don't see the point" that I am stating the obvious?
This is really odd, because I am in fact very conservative and yet there are some who wants to paint me a New Wave lunatic. I am the exact opposite of that.
Here is a quote below that has me scratching my head. I won't quote his name but you would instantly recognise it.
This is what he said:
"Back EMF has been known for almost 100 years now. It can be shown that as far as the amp is concerned the back EMF simply looks like a complex impedance and "most" amplifiers can handle "most" loudspeaker impedances with ease. There simply is no difference between back-EMF and impedance."
[Underlining added, but I could underlined everything!]
I agree 100% with that statement! What more can I say?
And yet just before that statement above, he said:
"Joe, I have no personal issues with you, but what you are claiming is, while not completely wrong, misleading and basically irrelevant."
What is he saying? What does "not completely wrong" mean and how can that be "misleading and basically irrelevant?"
I agreed with him 100% and I am misleading?
Maybe I am the one who should complaining, I stick to the rules and still get slapped down? Now I get Lorentz force thrown at me as if I was... well, I don't know. It all seems to so odd and I am not wanting to have a go at you any more than I want you to have a go at me. Hey, I want friends, not the other kind.
PM me and I will let you see the whole quote above and there is no problem as I have his permission even to name him here.
I am the last person to stir up controversies, but I am a very inquisitive guy and like a dog with a bone, I see so many people happy with only partial explanations and I saw holes in that. So I started to chase and see what the current actually does and figured out some rather interesting things.
I well know how easy it is to mislead oneself, I sharing with others who I knew correct me if it didn't add up (and sometimes it didn't). But because I was making some good points, they only gave me encouragement. These guys are very solid (scientists) and one of them is so crusty. At one point, over two weeks, I threw dozens of things at him, some he slapped down (and I expected this) and it was a great experience. I like somebody who plays the Devil's Advocate, as the verse says "one face sharpens the face of the other" (am I allowed to quote that from the Bible?). Then you have the ego driven stuff I have experienced on social media. That leaves me cold. Know what I mean?
Cheers (the eternal optimist), Joe
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on russian forum i found opinion that if amplifier distortions is independent of the load - chain which is mentioned yellow on the pic can be removed - so they are insisting to try both with and without that chains if u have a good solid amplifier
who tried or have some experience about it
You are completely right. It makes no sense to compensate for back EMF, it hinges on some arcane believe that back EMF is bad. It only is if you work with high output impedance amplifiers, such as some tube amps.
Edit: I see this picked up already, haven't visited this thread in some time and this was one of the first posts I came across. Joe, you are peddling nonsense.
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Good points. The more you look at it, what the current does, the more you realise that you can do a number of things, like crossovers and speaker design can be improved as well as amplifiers.
For example, people who like the sound of tube amplifiers are often accused of liking second and even order harmonic distortions and that they sweeten the sound. They are told they like distortion.
Here is a quote from Esa Merilainen's book "Currrent-Driving of Loudspeakers why supposedly some people like tube amps:
"On reason may be, of course, the 'warm' distortion produced by valves... valves [tubes] are not needed unless one is seeking certain distortion effects..."
Get the picture? You like tube amplification, then you like distortion.
MAYBE NOT!
What if tube amplifiers produce more distortion on the voltage side, and what if they produce less distortion on the current side? What are we hearing? Try a tube amp where the output tubes are forced almost into unity gain (near no gain of 1.5x) and then drive an output transformer that is say 20:1 - then 100mA on the Anodes produces 2 Amp on the secondary output. Is the transformer now a step-up device? In this case yes! The speaker now responds to the current and knows nothing but the current of the amplifier. The Voice Coil will not give a damn about the voltage of the amplifier. Under these circumstances you have a low distortion amplifier on both the voltage and current side, but it is the current side that really matters. The output impedance is typically <3 Ohm.
Use a setup with a low impedance current sense resistor of 0.1R, then multiply the voltage by about 60 (assuming a 6 Ohm DC resistance of the Voice Coil). Now you have recovered the Vre of the driver and this Vre corresponds to the current of the amplifier going through the VC and forms as a voltage that we can measure the distortion as if it was voltage, when in fact we can now measure the distortion of the current side of the amplifier in the same way we measure the voltage. Try measurement of the Vre with different amplifiers and you will get different results. If some produce more Vre distortion, then that is what you will be hearing. Even different speakers will make the amplifier's VRe measure different, especially worse if they have a non-linear impedance.
So yes to your question. This can lead to better things. Like the Elsinores have this amazing 'accessibility' to its sound. No restrictions in height, width and depth, no false brightness so typical of other commercial speakers. They also seems to have unrestricted dynamics. This is what others are hearing and they are not wrong. The Elsinores were based on figuring out what current does, but also the advantage that the amplifier should produce the same current at all frequencies, that the current phase angle should be zero. This allows L1 and L2 to suppress the non-linear inductive EMF of the drivers. And the tweeter with waveguide means that C1 can be as little as 1/3rd the value and this means that isolation in the critical crossover, the high reactance of C1, basically achieves something very close to current drive, even if the amplifier is not current drive, but a conventional voltage amplifier. You will still get critical current drive at all times where it is most important: Near the crossover frequencies.
So yes, this is definitely all about the pursuit of better sound. Not 'warm' at all, basically more realism, like you would like to be there.
Cheers, Joe
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Joe, you are confusing things. Please read carefully what I (and others) wrote, and make sure you get the context right.
I (and everyone else) agree on Lorentz' force. No controversy on this.
However, the whole discussion was about the question raised in post 3272 and 3273. Please make sure to re-read those posts. The question was if/why the sound could be different with/without the impedance compensation networks. Part of your answer to this discussion was this:
I don't see how Class AB would be related to the question.
EQ of the current of the amplifier, so that the amplifier produces the same current at all frequencies, has a known effect on the Class AB transitions and avoids measurable high order distortions. The voltage and current only line up in time when the load is a resistor. The feedback can only correct the voltage but not the current. Line the two up and things work much better. But only if the load looks like a resistor.
Temporal Coherence on Amplifiers and Current EQ
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To no one in particular, it's not that simple What's happening on one side of the Zobel network, isn't happening on the other, that's the point of it. It seems timely to post this link, Variable Amplifier Impedance
What's happening on one side of the Zobel network, isn't happening on the other, that's the point of it. It seems timely to post this link, Variable Amplifier Impedance
Ahh... Rod Elliott, right here in ol' Sydney town.
He is not the only one. Ask Dave.
.
And now for a suitable break, Joe does other things:
YouTube
Was recorded on a six channel tube frontend that I made. You can get on Tidal streaming CD quality. I highly recommend Tidal.
PS: Recorded at Rancom Studios here in Sydney.
An externally hosted image should be here but it was not working when we last tested it.
YouTube
Was recorded on a six channel tube frontend that I made. You can get on Tidal streaming CD quality. I highly recommend Tidal.
PS: Recorded at Rancom Studios here in Sydney.
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