Litz Wire | MWS Wire
Litz Wire & Cable Manufacturer : Y. D. Kim Int'l Inc.
Who makes a speaker with Litz wire for VC?
-RNM
Litz Wire & Cable Manufacturer : Y. D. Kim Int'l Inc.
Who makes a speaker with Litz wire for VC?
-RNM
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Hi Richard,
That simply doesn't make any sense at even AM band frequencies. Not unless I'm missing something. You lose volume taken up by insulation and also a collection of smaller wires. Not unless they flatten to pack better. Even still, it doesn't make any sense. Then there is the cost angle..
-Chris
That simply doesn't make any sense at even AM band frequencies. Not unless I'm missing something. You lose volume taken up by insulation and also a collection of smaller wires. Not unless they flatten to pack better. Even still, it doesn't make any sense. Then there is the cost angle..
-Chris
Me in red, and following.
I've made large coils with Litz, and it is amazing to see them remain flat with inductance and resistance out to 50 kHz, requirement at the time was 1khz, but I wanted some headroom. Single strand didn't even remain flat to 300 hz, and it was an air core. One learns very quickly with large projects, that even if you make the specifications and the machine is world class, there will always be the eventual demand to upgrade performance. Giving them a factor of 50 means they will leave me alone for at least two years..perhaps I will even be able to retire with my dignity(whatever is left of it).
I personally would not care if my speakers had very low distortion, but that's me. Others may be more picky in their listening, so additional cost might be worth it.
Jn
Ps. To me, the most important listening audience for my rants, is the speaker manufacturer R and D engineers. They need to get off their duffs and improve their product rather than stick with 100 year old technology. Some are trying hard, some not, but they really need to understand the physics.
I've made large coils with Litz, and it is amazing to see them remain flat with inductance and resistance out to 50 kHz, requirement at the time was 1khz, but I wanted some headroom. Single strand didn't even remain flat to 300 hz, and it was an air core. One learns very quickly with large projects, that even if you make the specifications and the machine is world class, there will always be the eventual demand to upgrade performance. Giving them a factor of 50 means they will leave me alone for at least two years..perhaps I will even be able to retire with my dignity(whatever is left of it).
I personally would not care if my speakers had very low distortion, but that's me. Others may be more picky in their listening, so additional cost might be worth it.
Jn
Ps. To me, the most important listening audience for my rants, is the speaker manufacturer R and D engineers. They need to get off their duffs and improve their product rather than stick with 100 year old technology. Some are trying hard, some not, but they really need to understand the physics.
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I, for one, am doing my best to keep up. Some of this would be nearly impossible to implement in production but many ideas are worth pursuing.
The voice coil to basket link is not litz, its tinsel wire which consists of cotton or similar threads wrapped in thin copper foil for maximum flexibility. Its a bit of a PITA to deal with but has shown to hold up well. There are other possibilities for this as well as for the spider that handles most of the restoring force. However there is a substantial infrastructure in place for making speaker as they are. In fact most of the worlds factories for speaker parts have relocated to China and bringing new solutions to Chinese vendors can be challenging.
LMS did include skin effect in the speaker simulation models. Winding a voice coil with Litz is really interesting if it can be shown to make an improvement. It would sell in the Audiophile circles if its just hard to do. Highest return would be on tweeters where it would be the most difficult.
I remember comparing a litz coil (made from MWS wire) to an equivalent copper foil coil. The Q was significantly higher with the Litz coil and to much higher frequency. It was much less cost as well.
On the powdered metal (mush metal?) pole pieces maybe they behave more like laminations than solid. I don't have a driver handy with an accessible magnet structure or I could check for conductivity of the pole pieces.
The voice coil to basket link is not litz, its tinsel wire which consists of cotton or similar threads wrapped in thin copper foil for maximum flexibility. Its a bit of a PITA to deal with but has shown to hold up well. There are other possibilities for this as well as for the spider that handles most of the restoring force. However there is a substantial infrastructure in place for making speaker as they are. In fact most of the worlds factories for speaker parts have relocated to China and bringing new solutions to Chinese vendors can be challenging.
LMS did include skin effect in the speaker simulation models. Winding a voice coil with Litz is really interesting if it can be shown to make an improvement. It would sell in the Audiophile circles if its just hard to do. Highest return would be on tweeters where it would be the most difficult.
I remember comparing a litz coil (made from MWS wire) to an equivalent copper foil coil. The Q was significantly higher with the Litz coil and to much higher frequency. It was much less cost as well.
On the powdered metal (mush metal?) pole pieces maybe they behave more like laminations than solid. I don't have a driver handy with an accessible magnet structure or I could check for conductivity of the pole pieces.
Hi John,
I was referring to frequencies well outside the audio band. I have done a lot of practical work with speakers. Both in system design and failure analysis. With woofers there are enough problems with the mechanical cone behavior that would very likely bury any improvement brought about by litz wire. Current solutions seem to have hit a good balance with the flat wire to wind the voice coil.
You may be onto something with applications in midrange and tweeter drivers. I'm not sure how much importance a slightly varying inductance makes over the operating frequency range. Zobel networks help to correct for rising inductance. If these drivers are driven directly, as they would be in a top performing system, would the inductance change really affect performance that much? My current thinking is that litz wire may really help drivers used behind a crossover.
If there is a cost effective improvement in performance there, I'll be behind you 100% In a practical sense, I'm not sure I see it being effective.
-Chris
I was referring to frequencies well outside the audio band. I have done a lot of practical work with speakers. Both in system design and failure analysis. With woofers there are enough problems with the mechanical cone behavior that would very likely bury any improvement brought about by litz wire. Current solutions seem to have hit a good balance with the flat wire to wind the voice coil.
You may be onto something with applications in midrange and tweeter drivers. I'm not sure how much importance a slightly varying inductance makes over the operating frequency range. Zobel networks help to correct for rising inductance. If these drivers are driven directly, as they would be in a top performing system, would the inductance change really affect performance that much? My current thinking is that litz wire may really help drivers used behind a crossover.
If there is a cost effective improvement in performance there, I'll be behind you 100% In a practical sense, I'm not sure I see it being effective.
-Chris
Magnetic metal
(“Born in the USSR, boy”) 8-10times greater BHmax than C8 ferrite magnet
On a dissected 4inch car speaker, the center pole piece and the front plate show a dead short, I very much doubt they are compressed powdered metal
. The ferrite magnet shows open circuit.
LCR meter, 100Hz to 100kHz, Probe tips spacing 1mm
Hi Chris
Maybe not that important as John has confessed. But in the spirit of optimization…
Rising impedance is the manifestation of eddy currents at work.
The zobel network is good for counteracting the inductive effect toward the driving amplifier. It doesn't affect the eddy currents generation, nor their local effects.
George
Happy holidays Pavel
Sure, Holidays mode
Re monitoring the coil’s impedance in vivo. What to expect, how to interpret the readings regarding with what happens inside the motor.
What about starting with in vitro test.
Doing a set of impedance frequency sweeps with increasing signal level –say on 10 steps- on a driver (preferably a cone-less).
Tabulating the 10 Z readings for each frequency and plotting a Z versus signal level.
George
Sure, Holidays mode
Re monitoring the coil’s impedance in vivo. What to expect, how to interpret the readings regarding with what happens inside the motor.
What about starting with in vitro test.
Doing a set of impedance frequency sweeps with increasing signal level –say on 10 steps- on a driver (preferably a cone-less).
Tabulating the 10 Z readings for each frequency and plotting a Z versus signal level.
George
Hi Chris
Maybe not that important as John has confessed. But in the spirit of optimization…
Rising impedance is the manifestation of eddy currents at work.
The zobel network is good for counteracting the inductive effect toward the driving amplifier. It doesn't affect the eddy currents generation, nor their local effects.
George
Until we come up with a fundamentally new way of sound production.... I think we can just keep refining and refining what we have. So, every bit counts and adds to the total.
THx-RNMarsh
Insulating former and Litz is not to attack Le(x). It is to attack velocity induced gap flux modulation only. Yhis part of the discussion is only to attack intermodulation products.
Jn
Magnetic metal
(“Born in the USSR, boy”) 8-10times greater BHmax than C8 ferrite magnet
and only some uranium.
There are vanadium alloys that take high flux as well.
On a dissected 4inch car speaker, the center pole piece and the front plate show a dead short, I very much doubt they are compressed powdered metal
The ferrite magnet shows open circuit.
LCR meter, 100Hz to 100kHz, Probe tips spacing 1mm
Hi Chris
Maybe not that important as John has confessed. But in the spirit of optimization…
Rising impedance is the manifestation of eddy currents at work.
The zobel network is good for counteracting the inductive effect toward the driving amplifier. It doesn't affect the eddy currents generation, nor their local effects.I mentioned ruler flat L and R only to show the coils do not proximity even with high self induced fields.
George
Jn
Agreed.
It's almost like spending all the time developing methods of quickly igniting lots of candles, using piezo igniters, portable flames, carrying a flame with you, high power glow sticks, or mirrors and apertures to a central source...then someone says "what's that switch on the wall near the door for?""
I have never seen eddy based flux modulation ever considered, theorized, or tested.
Anybody else find that? I mean, I'm not a speaker guy, maybe it's been done?
Ps. Ragnar was the machine Speakerlab used to use to magnetize their assembled speaker magnets.
It was in their brochure, a pic of Andre (sp) using it on a 15 incher.
Jn
As I said, two fundamental problems, the driver, and how to drive it.
If you only want to try to optimize the "garbage" you can buy, that is fine. Somebody has to do the electronics end of it, and that certainly takes engineering skills.
But at some point, lasers, accelerometers, linear encoders, capacitive pickups, even pickup coils, shorting rings and unproduceable magnets, it's all lipstick on a pig. High tech lipstick, but still lipstick.
Even I can wet wind a Litz coil.
Don't let the fact that I am not a speaker guy confuse you. One of the best technicians I worked with, when I explained how to make or do something, would look at me dumbfounded and say "would you show me?". It is important that the engineer have the skill sets to build, otherwise you end up with magnets being built that can crush errant fingers to a pulp. My friend knew that well.
I am a magnet guy who knows the value of collaboration with those of other expertise.
Jn
Ps. If it were my job to produce a transducer with high accuracy, I would never accept what you consider state of the art. So many fundamental design flaws, some of which has not been understood, so could not be addressed.
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Part of the problem is, there are ways to make a much better pig, that doesn't need any lipstick. There's research projects that have made much better transducers than standard cone and magnet jobbies.
However - there is no business case for the expenditure to turn them into production products. 99.99% of the worlds music consumers are happy with what there is, and it's price points. HiFi as we consider it is a tiny market. So, lipstick for the pig is the only way to go for now.
To illustrate that, I was invited (for business) to the Horse Show at Olympia at the weekend...
They have a big screen slung over the arena to show close ups etc. There's also a big slung sound system. The sound was poor - all boom and tinkle, which was ok for commentary but awful for music when played. And the screen was dropping frames all the time.
No one else, as far as I could tell, noticed or cared....
However - there is no business case for the expenditure to turn them into production products. 99.99% of the worlds music consumers are happy with what there is, and it's price points. HiFi as we consider it is a tiny market. So, lipstick for the pig is the only way to go for now.
To illustrate that, I was invited (for business) to the Horse Show at Olympia at the weekend...
They have a big screen slung over the arena to show close ups etc. There's also a big slung sound system. The sound was poor - all boom and tinkle, which was ok for commentary but awful for music when played. And the screen was dropping frames all the time.
No one else, as far as I could tell, noticed or cared....
That's because they were not there for the screen or sound.
Ah, I've waited long enough and call no joy...(we have dropped below the hard deck)
Recall Demian's plot of current vs difference? The difference, with good coupling, should be the real or resistive value of the driven coil, but loops in the x/y plot showed. That is a consequence of something happening that is 90 degrees out of phase to the current.
Since the current is a direct representation of the force being applied to the mass, acceleration, what entity is 90 degrees out of phase with acceleration?
Velocity. So, what entity is velocity dependent?
Eddies are one. And as I've said, current control can't fix that.
Jn
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