Well, yeah that is the main point of using a 2.5 arrangement , it lets you use the drivers original sensitivity without having to drop it down to match the baffle step loss, plus you get two bass drivers so low frequency distortion is less.
It has been my experience that compensating for baffle step doesn't make the low pass filter anymore complicated than it already is, since the inductor value goes up and that is compensated by the cap value going down in a typical second order electrical filter. No separate mid range notch filter required.
As far as baffle step correction being unnecessary, I think you just opened a whole new can of worms making statements like that.
... and the short answer is not usually the scientific answer, nor the accepted answer found among electrical engineers.
Or if you do, you won't be talking science.
Whether a device is voltage-operated or current-operated isn't a matter of arbitrary choice, point of view, or convention, although there are conventions, and the convention is that voltage-operated devices are indeed called voltage-operated devices.
This is pure nonsense, and an exercise in hand-waving and smokescreens.
It represents high-school level pseudo pop-science at its best.
In the same manner, clever teachers will claim that gold is the best conductor, or that the earth circles the sun.
Another piece of pseudo-science.
The only matching 'constants' (variables) in any physical device will be power, which is neither created nor destroyed.
Thus, the power in matches the power out,
and the sound generated plus heat dissipated must tally up.
To claim "Force is only constant for constant current" is not only false, but nonsensical and non-scientific. It is a lexically empty expression due to ambiguity and imprecision and so is meaningless.
Again, more hand-waving and pseudo-science.
You plainly misunderstand 'force' as a Newtonian concept.
I suggest you take a physics course and get a grip on the terms you are throwing around.
Your use of the word 'constant' is also confusing and lexically empty.
Whenever a speaker cone is accelerating, neither the voltage nor the current will be constant.
No, we don't drive speakers with low impedance sources by convention at all.
We do so because this increased the damping factor and results in a less distorted signal.
There is no convention involved at all in the choice of low impedance sources for loudspeakers.
Well whoever "we" is, real designers of both drivers and speaker enclosures don't "tend to design" for flat response from a constant voltage", but they actually do design striving for flat response from a given controlling voltage, not a current. This makes a speaker a voltage-controlled device.
The reason they do this, is not convention, but because speaker drivers as actually designed respond most linearly to voltage signals across their operating range, not to 'current signals'.
Now I see you have invented yet another new term in your pseudo pop-science bag of terminology:
We have progressed from "a current device" (meaningless term #1) to"a current drive device" (meaningless term #2, another term coined by you but not given a definition in scientific literature or the field of electronics.)
Quite true,
but as usual the short answer is sloppy enough to be both meaningless and misleading.
regards,
Nazaroo
ah, no, you may not.
Or if you do, you won't be talking science.
Whether a device is voltage-operated or current-operated isn't a matter of arbitrary choice, point of view, or convention, although there are conventions, and the convention is that voltage-operated devices are indeed called voltage-operated devices.
This is pure nonsense, and an exercise in hand-waving and smokescreens.
It represents high-school level pseudo pop-science at its best.
In the same manner, clever teachers will claim that gold is the best conductor, or that the earth circles the sun.
Another piece of pseudo-science.
The only matching 'constants' (variables) in any physical device will be power, which is neither created nor destroyed.
Thus, the power in matches the power out,
and the sound generated plus heat dissipated must tally up.
To claim "Force is only constant for constant current" is not only false, but nonsensical and non-scientific. It is a lexically empty expression due to ambiguity and imprecision and so is meaningless.
Again, more hand-waving and pseudo-science.
You plainly misunderstand 'force' as a Newtonian concept.
I suggest you take a physics course and get a grip on the terms you are throwing around.
Your use of the word 'constant' is also confusing and lexically empty.
Whenever a speaker cone is accelerating, neither the voltage nor the current will be constant.
No, we don't drive speakers with low impedance sources by convention at all.
We do so because this increased the damping factor and results in a less distorted signal.
There is no convention involved at all in the choice of low impedance sources for loudspeakers.
Well whoever "we" is, real designers of both drivers and speaker enclosures don't "tend to design" for flat response from a constant voltage", but they actually do design striving for flat response from a given controlling voltage, not a current. This makes a speaker a voltage-controlled device.
The reason they do this, is not convention, but because speaker drivers as actually designed respond most linearly to voltage signals across their operating range, not to 'current signals'.
Now I see you have invented yet another new term in your pseudo pop-science bag of terminology:
We have progressed from "a current device" (meaningless term #1) to"a current drive device" (meaningless term #2, another term coined by you but not given a definition in scientific literature or the field of electronics.)
Quite true,
but as usual the short answer is sloppy enough to be both meaningless and misleading.
regards,
Nazaroo
I bow to your superior knowledge on the subject.
I've been truly put in my place.
Regards,
David
I've been truly put in my place.
Regards,
David
Truly magnanimous. It's amazing that you worked at KEF all those years without knowing about this...anyway, we can now move on. 😎
I've just realised that Troels' 2.5 Ellam has a nice reflex bookshelf lurking in it. You just dump the second woofer and all that bafflestep nonsense. Might even be able to turn it to closed box with a resistor on the woofer. The Scanspeak 15W/8530K00 has a pleasantly small inductance of 0.35mH. The Qts of 0.27 opens some interesting possibilities for wiring the two woofers in series too. You could do an unusual D'appolito design that way.
I just burst with creative ideas really. 😀
haha current vs voltage? Like chicken and egg...
hilarious.
By the end i couldnt care which was correct.
In my field of expertise a reactive device would be referred to as current controlled. Since phase angle is referred to current, more often than not.
Also POWER, being a rate, doesnt have to conform to conservation of ENERGY. the energy is conserved, but the rate of energy transduction MUST be constant for your assertion to be true.
Far better carcasses for the vultures to pick over lol.
hilarious.
By the end i couldnt care which was correct.
In my field of expertise a reactive device would be referred to as current controlled. Since phase angle is referred to current, more often than not.
Also POWER, being a rate, doesnt have to conform to conservation of ENERGY. the energy is conserved, but the rate of energy transduction MUST be constant for your assertion to be true.
Far better carcasses for the vultures to pick over lol.
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Although most of the "critique" is nonsense and the criticisms not accompanied by any argument past "you're wrong," the valid point (although irrelevant here) is that one can indeed have voltage without current and current without voltage in the Platonic limits of infinite resistance and zero resistance. The conserved quantities in any situation are charge and energy.
I think we all understand that a loudspeaker coil without resistance would just blow up a transistor (voltage) amplifier. A valve (current) amplifier probably wouldn't bat an eyelid. 😀
All ends up in the same place really. There's an end to it. 😎
An externally hosted image should be here but it was not working when we last tested it.
All ends up in the same place really. There's an end to it. 😎
Lets just say I'm a stickler for accurate expression.
And in that spirit,
thank you for your good grace. Apparently manners are important at KEF, which may indeed be more significant than scientific accuracy.
Well, I strongly suspect this interesting convention is a hangover from the transistor era, where the focus changed to current-control generally.
Even better and more accurate. 😀
Conservation of Energy is a famous axiom.
By 'power' most people in general parlance are really talking about the energy transferred, rather than the rate at which energy is transferred. 😉
For instance, speaker efficiency might be expressed in terms of a percentage of power, meaning really a measure of the amount of energy that is transformed as intended sound vs. the amount of energy lost to dissipation as heat, friction, etc.
"I see your Schwartz is as big as mine" - Dark Helmet, Spaceballs
SY said:
Although most of the "critique" is nonsense ...the valid point (although irrelevant here) is taken. 🙄
Lol of course SY you are correct; however common sense says that we all know, neither infinite R or zero R is actually possible....coming from an industry where Im measuring resistances in the order of 1-100 + Gig ohms, and of course, current still passes, albeit, at miniscule levels.
Also like we know there are better conductors than gold, but are we REALLY going to use them? How about some high temp superconducting voice coils? anyone? In my opinion this is what I hate about THEORY. Its not incorrect, just not applicable, in reality.
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I did have a few clever high school teachers and luckily none of them was stupid enough to claim that gold is the best conductor.
Mine correctly claimed that it is silver.
Hi,
Good grief. What a load of meaningless drivel regarding voltage drive.
For a loudspeaker, like any other coiled magnetic system, e.g. inductors,
solenoids, relays, motors etc, the physical reality is it is the current in
the coils that matters, completely independent of the type of drive
the system has.
Finding the simplest image I can :
Its completely clear its the current in a driver that operates a typical loudspeaker driver.
rgds, sreten.
http://www.tolvan.com/basta/Basta!TechDoc.htm
Good grief. What a load of meaningless drivel regarding voltage drive.
For a loudspeaker, like any other coiled magnetic system, e.g. inductors,
solenoids, relays, motors etc, the physical reality is it is the current in
the coils that matters, completely independent of the type of drive
the system has.
Finding the simplest image I can :
Its completely clear its the current in a driver that operates a typical loudspeaker driver.
rgds, sreten.
http://www.tolvan.com/basta/Basta!TechDoc.htm
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+1
Digging that image. puts it clearly so even a dunce like myself gets it.
Brilliant Charles, I should have remembered the thing about silver......im using it electrically all the time! Kind of like the assumption that copper is commonly used, because it is (or WAS) cheap. Just as important is the tensile strength, IIRC Aluminium isnt far behind copper, but in tension...not so good. You should see what happens to SOME Al wound rotors under stress....
Digging that image. puts it clearly so even a dunce like myself gets it.
Brilliant Charles, I should have remembered the thing about silver......im using it electrically all the time! Kind of like the assumption that copper is commonly used, because it is (or WAS) cheap. Just as important is the tensile strength, IIRC Aluminium isnt far behind copper, but in tension...not so good. You should see what happens to SOME Al wound rotors under stress....
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As far as I am aware super conductors do posses zero resistance and can have a current flowing through them without any applied voltage.
yes, my mistake. ALthough...im not sure about high temp superconductors since these are 'relatively' new, and are not operated at 0°K, so resistance IS present. Im sure that its R is nigh on un-measureable though.
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Correct Charles.
Unfortunately my (other) son came home confused because a teacher taught that gold was the best conductor, but too expensive.
I opened my 1st year Physics text and showed him that silver was indeed a better conductor.
I explained that silver was not used for contacts because of corrosion, not conductivity.
I explained that gold was used for contacts, not because of conductivity, but lack of corrosion.
He immediately went back to school, had a fierce argument with the teacher, and he was expelled.
I had failed to explain that the best conductor of other things, like business, is politeness. oops.
Ignorance trumps science every time,
both for perpetuating BS, and causing it.
Due to advances in science and engineering, currently the best conductor of static is Internet fora.
Strange, mine always claimed Herbert von Karajan was the best conductor. They threw up their hands in disgust when I said Eugene Ormandy.
(It's Otto Klemperer, really)
I thought the definition itself of a super conductor was when a material transitions into the range of operation that gives it zero resistance. I wasn't aware that there was any difference between the low and high temperature variants once that point has been reached. Of course I am not completely sure about this either but no super conductor is ever operated at 0°K, only close to it and 'hot' super conductors still need cooling down to very low temperatures it's just that they can get by with liquid nitrogen, rather then needing liquid helium.
If one could develop a room temperature superconducting material it would certainly be marvellous, though no doubt it would be quite useless for a voice coil with typical amplifiers.
Zero R is.
Doable. One of the hastalloy backed HTS from american super, wrapped on a kapton former, bonded with polyimid or stycase 2850ft. Run with the magnetic circuit cooled to nitrogen temps, helium in the gap.
The warm to cold leads would be the problem..gas cooled leads are a PITA.
Yup, you are correct.
It's zero at 1.8K, zero at 4.5K, and zero at 77K. But for use in rotating machinery and for AC, the eddy currents of the hastalloy or stainless or silver substrate heat the conductor up. The biggest app so far for HTS is energy storage, use as the inner core magnet in the 20 to 40 tesla range, and short 3 phase power transmission lines. It's not ready for prime time for accelerator magnets or MRI's
There are room temperature superconductors..
Problem is, it's a very very very very cold room. 😉
jn
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