Moray,
I do use damping on My ribbon drivers and more so below 800 hz. on a ESL an open stator is far less efficient than a perf metal stator, this is the reason for perf stator, it is for more efficiency. If someone thought otherwise he missed ESL 101. 🙂
For clarity , if you are talking for bass then i would agree and use a perf stator , but for mid/high frequencies an open stator is superior .
Now on a 30 -40 % open stator , where you are going for better damping and efficiency , what happens to the speaker in relation to phase angle with frequencies above 8K ?
AW
I do use damping on My ribbon drivers and more so below 800 hz. on a ESL an open stator is far less efficient than a perf metal stator, this is the reason for perf stator, it is for more efficiency. If someone thought otherwise he missed ESL 101. 🙂
For clarity , if you are talking for bass then i would agree and use a perf stator , but for mid/high frequencies an open stator is superior .
Now on a 30 -40 % open stator , where you are going for better damping and efficiency , what happens to the speaker in relation to phase angle with frequencies above 8K ?
AW
If I recall correctly...
the aluminum screen wire had open areas that were 1/16" x 1/16" and the wire was the standard that we all see in bug screen. The perf metal had much larger size holes but a lot less open area overall. That was where the surprise came in. The bug screen had much better coverage as well as a far more open area but the perf metal worked better. I think that what was happening was that the reduced open area of the perf metal provided a better air impedance match between the diaphragm and the air in the room and that may be why the efficiency was better.
the aluminum screen wire had open areas that were 1/16" x 1/16" and the wire was the standard that we all see in bug screen. The perf metal had much larger size holes but a lot less open area overall. That was where the surprise came in. The bug screen had much better coverage as well as a far more open area but the perf metal worked better. I think that what was happening was that the reduced open area of the perf metal provided a better air impedance match between the diaphragm and the air in the room and that may be why the efficiency was better.
Ok,
I see, it would appear that he was using too thin a stator to generate a proper field, i would think, using something as thin as a bug screen !
I see, it would appear that he was using too thin a stator to generate a proper field, i would think, using something as thin as a bug screen !
See, this is what I am talking about. People think there hear a specific effect and then come up with all sorts of ideas about it, but no one tests the ideas so in the end, all that remains is some guy on a forum said this or that and people accept it as truth when the reality is it has never been tested.
There is no such thing as the stator being too thin to produce the required electric field. It is simple physics. 1 atom thick metal would be sufficient, but not desirable from a mechanical standpoint. Quad ESL63s for example use what is essentially perforated PCB material with a layer of copper that is certainly much thinner than the wire used in window screens.
If you want make meaningful speculation on why there may have been a difference between the speakers you have to know if all other aspects of the speakers were identical and the only difference was the construction of the stators. This seems unlikely due to the different mechanical construction techniques that would be required to support a flexible wire screen and relatively rigid perforated sheet metal.
In the end, ESL construction is dictated by aesthetic and practical considerations such as size of room and space available for the speakers, and by mechanical requirements- you have to keep a large surface area device rigid and that requires certain construction practices.
ESLs are NOT as complex as people keep trying to make them out to be. I say this from experience, not from speculation about quantum mechanical effects and other mumbo-jumbo that creeps into anything having to do with quality audio. There is no ideal formula for diaphragm coatings and no one best circuit for bias supply. There is only what works and what doesn't, what is safe and what isn't, what is reliable and what isn't. Audible differences between materials are at most minor and most of the time probably exist in the mind of the listener more than in their ears.
I_F
There is no such thing as the stator being too thin to produce the required electric field. It is simple physics. 1 atom thick metal would be sufficient, but not desirable from a mechanical standpoint. Quad ESL63s for example use what is essentially perforated PCB material with a layer of copper that is certainly much thinner than the wire used in window screens.
If you want make meaningful speculation on why there may have been a difference between the speakers you have to know if all other aspects of the speakers were identical and the only difference was the construction of the stators. This seems unlikely due to the different mechanical construction techniques that would be required to support a flexible wire screen and relatively rigid perforated sheet metal.
In the end, ESL construction is dictated by aesthetic and practical considerations such as size of room and space available for the speakers, and by mechanical requirements- you have to keep a large surface area device rigid and that requires certain construction practices.
ESLs are NOT as complex as people keep trying to make them out to be. I say this from experience, not from speculation about quantum mechanical effects and other mumbo-jumbo that creeps into anything having to do with quality audio. There is no ideal formula for diaphragm coatings and no one best circuit for bias supply. There is only what works and what doesn't, what is safe and what isn't, what is reliable and what isn't. Audible differences between materials are at most minor and most of the time probably exist in the mind of the listener more than in their ears.
I_F
I don't think it was the size of the stator wire...
I have built a good number of panels using #28 and mostly #30 gage double build magnet wire and tefzel wire wrap wire on 1/2 inch cube louvre as a base (just as in Acoustat's) with 15 -24 wires per inch. The 15 wire per inch had the same open area as the stock Acoustat's (which used 24 gage wire with very thick PVC dielectric) at 5-6 wires per inch. The 24 wire per inch versions are the best ones. I would guess their open area around 35% perhaps a little less. I use a 24 thread per inch threaded rod to align the wires so they are very uniform. It is fast and easy to wind a stator this way. The adhesive bonding is the slow part as I don't like to use really toxic adhesives. Citrus based model cement glue works well but it is slow to harden up. But you only have to do this once. I have yet to try this method with proper application of dilute base coat then full strength PVA adhesive which is totally non toxic but I do plan to give it a go sooner or later.
I have built a good number of panels using #28 and mostly #30 gage double build magnet wire and tefzel wire wrap wire on 1/2 inch cube louvre as a base (just as in Acoustat's) with 15 -24 wires per inch. The 15 wire per inch had the same open area as the stock Acoustat's (which used 24 gage wire with very thick PVC dielectric) at 5-6 wires per inch. The 24 wire per inch versions are the best ones. I would guess their open area around 35% perhaps a little less. I use a 24 thread per inch threaded rod to align the wires so they are very uniform. It is fast and easy to wind a stator this way. The adhesive bonding is the slow part as I don't like to use really toxic adhesives. Citrus based model cement glue works well but it is slow to harden up. But you only have to do this once. I have yet to try this method with proper application of dilute base coat then full strength PVA adhesive which is totally non toxic but I do plan to give it a go sooner or later.
In many cases, the quality of design is more important than the fundamental technique (ribbon/esl or hybrid/fullrange).
Making general statements about which is the best doesn't work most of the time.
Making general statements about which is the best doesn't work most of the time.
A mild rebuke PhaseLockLoopy- as someone who worked as a salesman in both audio and music shops for 20 years, I don't appreciate the 'slimy salesman' comment earlier at all. In all my time in retail I attempted to sell based on the needs of the customer, and virtually all my colleagues did too. Yes, it's business and you need to make a sale, but my philosophy always was to treat people properly to create a good relationship with the customer, that way the customer gets what they want and you get more business. It's fortunate for any dealer selling ribbons and electrostats that your prejudice means you are unlikely to trouble them by wasting a bunch of their time listening to equipment for research purposes that you'd have no intention of buying! I would also point out that I won't be the only member of the forum who has worked in retail! Salespeople may be convenient stereotypes to act as hate figures for some people, but the folks I worked with over the years- despite the odd cynic- were people who cared about audio, music and their customers, despite all too common experiences of time-wasting or abuse.
Hi,
😀
Guess, I´m doing right that for 25 years and ought to know one thing or two by now about the differences between sheet metal and wire stators and haven´t had one measurement yet which gave a hint to any phase smear effect (and I´m not talking about cheap diy-measuring stuff here!).
But since you brought this topic, I ask You kindly to proove Your (repeated) claim and show us just one measurement showing this effect!
And no, to built a ultimate ESL is no question of perf metal or wire, but to know which one suits the application best. Sheet metal has advantages with smaller d/s spacings while wire is fine for larger d/s spacing. So I wouldn´t use sheet metal for a fullranger or bass, as I do for my hybrid-panels. Wire is probably the best and easiest to use for a bass-panel (the safety requirements alone for the needed voltage values rather rule out perf metal sheets!)
Wayne´s assumption is quite the opposite, but still I regard it as wrong. So I admit not to know ESL101 at all 😀
If your aim is for example to reach highest dynamic capabilities and resolution a fully driven sheet metal panel outperforms a segmented wire stator. You can proove this in praxi as well as in theory!
A sheet metal stator usually needs far lower transformation-factors (~ factor 2) which eases the transformer design, reduces losses and allows for improved sonics simply through the superior qualities of the transformer-panel system. I find it for example rather peculiar that someone actually thinks that a transformation factor of >>200 can be of any good (see Quad).
So the ultimate ESL could only be the one that fits certain parameters and needs best and since those are variable, there is no such thing as the ultimate ESL or Ribbon or loudspeaker in general.
That is -besides rising conceptual and constructional difficulties and other severe disadvantages- the reason why I stick to hybrid-ESLs assisted by dynamic bass drivers.
It´s my opinion that the ESL with the best overall performance is a hybrid.
jauu
Calvin
Oh my gosh, I can´t see a thing! It must be some invisible alien mindray frying my brains! (just kiddin, forgive me, but I´m Calvin am I?)
😀Guess, I´m doing right that for 25 years and ought to know one thing or two by now about the differences between sheet metal and wire stators and haven´t had one measurement yet which gave a hint to any phase smear effect (and I´m not talking about cheap diy-measuring stuff here!).
But since you brought this topic, I ask You kindly to proove Your (repeated) claim and show us just one measurement showing this effect!
And no, to built a ultimate ESL is no question of perf metal or wire, but to know which one suits the application best. Sheet metal has advantages with smaller d/s spacings while wire is fine for larger d/s spacing. So I wouldn´t use sheet metal for a fullranger or bass, as I do for my hybrid-panels. Wire is probably the best and easiest to use for a bass-panel (the safety requirements alone for the needed voltage values rather rule out perf metal sheets!)
Wayne´s assumption is quite the opposite, but still I regard it as wrong. So I admit not to know ESL101 at all 😀
If your aim is for example to reach highest dynamic capabilities and resolution a fully driven sheet metal panel outperforms a segmented wire stator. You can proove this in praxi as well as in theory!
A sheet metal stator usually needs far lower transformation-factors (~ factor 2) which eases the transformer design, reduces losses and allows for improved sonics simply through the superior qualities of the transformer-panel system. I find it for example rather peculiar that someone actually thinks that a transformation factor of >>200 can be of any good (see Quad).
So the ultimate ESL could only be the one that fits certain parameters and needs best and since those are variable, there is no such thing as the ultimate ESL or Ribbon or loudspeaker in general.
To perform on an comparable level the ESL had to be of considerable larger size. The reason for this is that ESLs can´t produce as much power per unit area as dynamic speakers and therefore a ESL always has to have larger diaphragm area.
That is -besides rising conceptual and constructional difficulties and other severe disadvantages- the reason why I stick to hybrid-ESLs assisted by dynamic bass drivers.
It´s my opinion that the ESL with the best overall performance is a hybrid.
jauu
Calvin
Thats the way. Neo magnets too infinity IRS V. And ribbon tweeters too Accustat.
http://www.6moons.com/audioreviews/roadtour13/roadtour13.html
http://www.6moons.com/audioreviews/roadtour13/roadtour13.html
ABJensen,
have you thought about doing it like Stage Accompany an others? Would you lose too much diaphragm surface due to the front pole plates?
have you thought about doing it like Stage Accompany an others? Would you lose too much diaphragm surface due to the front pole plates?
el`Ol said:
Yes I have.but the only reason I can see is it is easier too make.because you dont need return wire.The problem is you get more reflektions from the iron and more non-linear field . And now it is 93db one watt. Thats enough for me.
ribbons vs electrostats
I`ve been following this thread with great interest. From my personal experience ESL`s sound hyperdetailed and dynamic in the midrange, but with very limited dynamic range in the high and low frequency portions of the spectrum. They seemingly offer more detail than exists in live music, without a proper timbre rendering of a complete instruments (or voice) sound. The most lifelike timbre I ever heard from an ESL was when I listened to one of the biggest Soundlab speakers. Most ESL`s I ever auditioned were thin sounding though. There is one particular thing that really bothers me with ESL`s and that is the sound of the foil, which is very specific. They are very sensitive to the quality of electricity and on a bad day they give a very syrupy, dead sound. Although all speakers (and systems) suffer from this to a degree, ESL`s are especially sensitive to this problem. Corrugated ribbons on the other hand, give too much artificial "sparkle" that I find downright annoying and "hifi-ish" in character. Although very airy and transparent, they have a sort of "greyish" (odd order distortions) character to their sound, which is not very close to the live sound. I do consider flat non-corrugated ribbons very interesting though and I believe that for a midrange usage they only need to be corrugated at their ends (suspension) in order to provide some practical movement of the foil. Planar magnetics are potentially very interesting, especially the likes of modified Maggies (Magnestand). I do like detailed sound, but only if it`s tonally correct. Don`t want to start a war, just my 5 cents.
I`ve been following this thread with great interest. From my personal experience ESL`s sound hyperdetailed and dynamic in the midrange, but with very limited dynamic range in the high and low frequency portions of the spectrum. They seemingly offer more detail than exists in live music, without a proper timbre rendering of a complete instruments (or voice) sound. The most lifelike timbre I ever heard from an ESL was when I listened to one of the biggest Soundlab speakers. Most ESL`s I ever auditioned were thin sounding though. There is one particular thing that really bothers me with ESL`s and that is the sound of the foil, which is very specific. They are very sensitive to the quality of electricity and on a bad day they give a very syrupy, dead sound. Although all speakers (and systems) suffer from this to a degree, ESL`s are especially sensitive to this problem. Corrugated ribbons on the other hand, give too much artificial "sparkle" that I find downright annoying and "hifi-ish" in character. Although very airy and transparent, they have a sort of "greyish" (odd order distortions) character to their sound, which is not very close to the live sound. I do consider flat non-corrugated ribbons very interesting though and I believe that for a midrange usage they only need to be corrugated at their ends (suspension) in order to provide some practical movement of the foil. Planar magnetics are potentially very interesting, especially the likes of modified Maggies (Magnestand). I do like detailed sound, but only if it`s tonally correct. Don`t want to start a war, just my 5 cents.
Hi,
The thin sound is probably caused by improperly designed full range esls.
If bass lacks, you will hear details in the midrange you didn't notice before (hyperdetail). That's probably the reason you only liked the very big esls.
Some esls like quad are a bit shy in highs because of additional protective grills/foils. But it can be the other way round as well.
I can't understand the fluctuating performance unless humidity of air is a factor.
The thin sound is probably caused by improperly designed full range esls.
If bass lacks, you will hear details in the midrange you didn't notice before (hyperdetail). That's probably the reason you only liked the very big esls.
Some esls like quad are a bit shy in highs because of additional protective grills/foils. But it can be the other way round as well.
I can't understand the fluctuating performance unless humidity of air is a factor.
Re: ribbons vs electrostats
I think it is all about controlled motion of an area of foil or film.
Whether driven by lorentz force or electrostatically does not
matter to our ears. Using electrostatic force it is maybe more
easy to apply that force to a larger area. Using lorentz force
this is more difficult and you have to introduce voice coil like
structures on the moving foil by glueing, printing or vaporizing.
In case of a magnetic transducer with large area the shape of
the magnetic field gets more complex, because you will need
more than one N-S pole and you cannot avoid to place magnets
in front or behind the diaphragm.
Thats why a "true" ribbbon tends to implement a line source.
This is the "natural" way of constuction, which is able to
keep the diaphragm free from disturbing magnet structures in
front or behind, thereby allowing dipole radiation
if you want.
But the normal way of doing this, using a long ribbon
fixed at its short ends and folded or rippled multiply along
the short side, leads to some disadvantages.
- the ribbon produces a bowing along the long side when moving,
with maximum excursion in the middle. This is commonly solved
by introducing some more fixing points along the ribbon, if its
a really long one.
- there is a long slot at both sides of the ribbon, it cannot
contact airtight to the magnet pieces. Both slots are bordered
by the diaphragm, which is thin and sharp.This causes noise and
distortion with higher excursions.
- because of the high excursion in the middle, the magnetic
gap has to be rather deep along the whole length of the
ribbon to obtain a homogenous field, even though you would
not need that depth of the gap along the whole length concerning
excursion only.The deep magnetric gap will cause protruding edges
in front and behind the ribbon, which spoils radiation pattern
and proper acoustic coupling with the surrounding air.
- it is impossible to adjust the diaphragm to a resonant frequency
high enough for practical efficiency unless using tension along
the ribbon - which in turn causes AGEING.
All of those problems can be solved by using a folding along the long
side of the "ribbon".
- The long sides can contact the pole pieces in an airtight manner.
- Excursion is - mutually - the same over the whole length of the ribbon.
Depth of the magnetic gap can be reduced, the diaphragm can be
mounted to change almost flat into the speakers cabinets baffle.
- Resonant frequency is tuned by appropriate folding (rippling)
concerning the mass of the diaphragm material used.
- The structure can be mounted into the frame without using tension,
which yields very good long term stability.
- Even this structure will bend when driven, but the bending mode will
improve the horizontal radiation angle, because it bends along the
short sides.
To be honest, by folding the long side, there arise some technical
problems. E.g. the electrical contacts at both ends have to be designed
not to disturb the bending motion or to introduce bending in unwanted
directions. But that can be done by proper design and experience.
IMO this kind of "ribbon" is in advantage over an electrostatic
device in at least three aspects:
- capability of large linear excursion
- far less diaphragm area needed, which leads to far less
problems with unwanted vibrational modes and beaming
- unobstructed area in front and behind the diaphragm
And by the way: This is exactly the way it sounds.
Regards
fivestring said:
I think it is all about controlled motion of an area of foil or film.
Whether driven by lorentz force or electrostatically does not
matter to our ears. Using electrostatic force it is maybe more
easy to apply that force to a larger area. Using lorentz force
this is more difficult and you have to introduce voice coil like
structures on the moving foil by glueing, printing or vaporizing.
In case of a magnetic transducer with large area the shape of
the magnetic field gets more complex, because you will need
more than one N-S pole and you cannot avoid to place magnets
in front or behind the diaphragm.
Thats why a "true" ribbbon tends to implement a line source.
This is the "natural" way of constuction, which is able to
keep the diaphragm free from disturbing magnet structures in
front or behind, thereby allowing dipole radiation
if you want.
But the normal way of doing this, using a long ribbon
fixed at its short ends and folded or rippled multiply along
the short side, leads to some disadvantages.
- the ribbon produces a bowing along the long side when moving,
with maximum excursion in the middle. This is commonly solved
by introducing some more fixing points along the ribbon, if its
a really long one.
- there is a long slot at both sides of the ribbon, it cannot
contact airtight to the magnet pieces. Both slots are bordered
by the diaphragm, which is thin and sharp.This causes noise and
distortion with higher excursions.
- because of the high excursion in the middle, the magnetic
gap has to be rather deep along the whole length of the
ribbon to obtain a homogenous field, even though you would
not need that depth of the gap along the whole length concerning
excursion only.The deep magnetric gap will cause protruding edges
in front and behind the ribbon, which spoils radiation pattern
and proper acoustic coupling with the surrounding air.
- it is impossible to adjust the diaphragm to a resonant frequency
high enough for practical efficiency unless using tension along
the ribbon - which in turn causes AGEING.
All of those problems can be solved by using a folding along the long
side of the "ribbon".
- The long sides can contact the pole pieces in an airtight manner.
- Excursion is - mutually - the same over the whole length of the ribbon.
Depth of the magnetic gap can be reduced, the diaphragm can be
mounted to change almost flat into the speakers cabinets baffle.
- Resonant frequency is tuned by appropriate folding (rippling)
concerning the mass of the diaphragm material used.
- The structure can be mounted into the frame without using tension,
which yields very good long term stability.
- Even this structure will bend when driven, but the bending mode will
improve the horizontal radiation angle, because it bends along the
short sides.
To be honest, by folding the long side, there arise some technical
problems. E.g. the electrical contacts at both ends have to be designed
not to disturb the bending motion or to introduce bending in unwanted
directions. But that can be done by proper design and experience.
IMO this kind of "ribbon" is in advantage over an electrostatic
device in at least three aspects:
- capability of large linear excursion
- far less diaphragm area needed, which leads to far less
problems with unwanted vibrational modes and beaming
- unobstructed area in front and behind the diaphragm
And by the way: This is exactly the way it sounds.
Regards
Attachments
@LineArray,
I agree with your interesting observations. I never did understand how a classic corrugation could reinforce the ribbon structure in any way, without creating more problems than it was aiming to solve. Awhile back I was thinking of vertical corrugation too, but was wondering if the air load in front and back of the ribbon would put too much pressure on the foil and force it to expand under higher excursion, which in turn could cause a short circuit (I hope I understood what you said, the photos have really low resolution). All this may not be valid for short ribbons,but for taller ribbons I do have some reservation though. I already successfully modified some commercial (smaller) ribbons with flat foils, but I am using them only well above 6 khz, because I find them very undynamic sounding below this frequency. From a phone conversation I`ve had with Aleksander Radisavljevic (RAAL), he told me how corrugated ribbons totally loose their control under high power/excursion and move chaotically. I guess even a small blast of wind could make them wave like a flag. I am considering of building myself a taller (1 or 1.5m) ribbon and am thinking of making it totally flat. I am interested only in the range above 300 hz and I wonder how much excursion would be needed in that range with a planned 2 order crossover. The ribbon itself would be about 2 cm wide and with a length of some 1.5 m there is already 300 square cm of effective surface, which is more than a 8" woofer has. I planned only a single corrugation at both ends, perhaps with small mylar foil reinforcement in order to provide some excursion under higher power. I am not sure if there is any practical need for extreme ribbon excursion in the midband and above (Advanced Ribbon Technologies claims 1" peak to peak excursion for their ribbons). At this excursion levels, doppler distortion must rise to enormous levels and the sound is probably horrible.
Best regards
I agree with your interesting observations. I never did understand how a classic corrugation could reinforce the ribbon structure in any way, without creating more problems than it was aiming to solve. Awhile back I was thinking of vertical corrugation too, but was wondering if the air load in front and back of the ribbon would put too much pressure on the foil and force it to expand under higher excursion, which in turn could cause a short circuit (I hope I understood what you said, the photos have really low resolution). All this may not be valid for short ribbons,but for taller ribbons I do have some reservation though. I already successfully modified some commercial (smaller) ribbons with flat foils, but I am using them only well above 6 khz, because I find them very undynamic sounding below this frequency. From a phone conversation I`ve had with Aleksander Radisavljevic (RAAL), he told me how corrugated ribbons totally loose their control under high power/excursion and move chaotically. I guess even a small blast of wind could make them wave like a flag. I am considering of building myself a taller (1 or 1.5m) ribbon and am thinking of making it totally flat. I am interested only in the range above 300 hz and I wonder how much excursion would be needed in that range with a planned 2 order crossover. The ribbon itself would be about 2 cm wide and with a length of some 1.5 m there is already 300 square cm of effective surface, which is more than a 8" woofer has. I planned only a single corrugation at both ends, perhaps with small mylar foil reinforcement in order to provide some excursion under higher power. I am not sure if there is any practical need for extreme ribbon excursion in the midband and above (Advanced Ribbon Technologies claims 1" peak to peak excursion for their ribbons). At this excursion levels, doppler distortion must rise to enormous levels and the sound is probably horrible.
Best regards
Hi,
imho one of the biggest failure one can make is to think that a large membrane area is something negative. Of course is it easier to have a wide dispersion with smaller, less wide structures, but the little you gain here (if it is of any positive use is debatable anyway) is offset by condsiderable losses in the dynamics and distortion department.
While the distribution character is rather a parameter which affects the kind of usage of a speaker (every day and everywhere->wide dispersion, fixed to a certain position-->listening as a act of doing nothing else besides) and is more a matter of higher freqs. Dynamics and distortion on the other hand are are directly influencing the complete frequency range and so the sound experience. It s my impression that every speaker that has deficiancies here, sounds artficial and unreal. You only can optimise dynamics and distortion at the same time by enlarging membrane area, but not by increasing excursion capabilities.
With regard to this ESLs can reach very high dynamics (comparable to horn speaker, but with even increased low level resolution) with exceptional low distortion values (the majority of distortion depends more on the used audio tranny than the panel itself).
If there would be any problem with the stators beeing ´obstacles´ within the soundpath one should see artifacts within the the distortion measurement, right? How comes then that the distortion values of a really good panel are much lower than any other principle especially at elevated SPLs?
jauu
Calvin
imho one of the biggest failure one can make is to think that a large membrane area is something negative. Of course is it easier to have a wide dispersion with smaller, less wide structures, but the little you gain here (if it is of any positive use is debatable anyway) is offset by condsiderable losses in the dynamics and distortion department.
While the distribution character is rather a parameter which affects the kind of usage of a speaker (every day and everywhere->wide dispersion, fixed to a certain position-->listening as a act of doing nothing else besides) and is more a matter of higher freqs. Dynamics and distortion on the other hand are are directly influencing the complete frequency range and so the sound experience. It s my impression that every speaker that has deficiancies here, sounds artficial and unreal. You only can optimise dynamics and distortion at the same time by enlarging membrane area, but not by increasing excursion capabilities.
With regard to this ESLs can reach very high dynamics (comparable to horn speaker, but with even increased low level resolution) with exceptional low distortion values (the majority of distortion depends more on the used audio tranny than the panel itself).
If there would be any problem with the stators beeing ´obstacles´ within the soundpath one should see artifacts within the the distortion measurement, right? How comes then that the distortion values of a really good panel are much lower than any other principle especially at elevated SPLs?
jauu
Calvin
fivestring said:
Hi fivestring, i think i understood the effect you feared.
Maybe unwanted expansion of folds when diaphragm is
loaded with over/underpressure at both sides respectively
could occur, when the folding is too deep and "edgy".
But that kind of folding is not desired anyway because the
compliance across the short side would be too high, giving
a fs which is too low. Such a folding would additionally increase
diaphragm mass to a higher extent, because more material is needed.
With the corrugation i used, this is really not an issue.
I tried to attach a better pic. The folding symply looks like
a miniature corrugated iron.
I thought of upsizing my tweeter before. To make it taller is no
problem. To make it wider (8mm wide now) is more tricky.
Using the same corrugation pattern, compliance will increase and
mass too. Which is your desired fs ? (100...200 Hz ?)
Maybe the corrugation has to be modified into flatter, maybe
at a certain point one has to think about a stiffer foil, i don't
know. But i feel probability is high, that one could make it wider
by changing nearly nothing.
I personally would not go to a completely flat diaphragm, because
i would fear uncontroled motion at the upper end of the frequency range
with a diaphragm 2cm wide. But i havent done it and maybe it is a way to go.
Would reinforcement of corrugated borders help at higher
frequencies, if the diaphragm is flat ? It seems rather complex,
but again maybe your idea is right.
I would like, if you kept me updated with your experimenting,
because someday i'd like to upsize my prototype and any
experience is valuable.
@calvin:
There seems to be a little misunderstanding. I don't think large
diaphragm area is negative as such. But please keep in mind, that the
area of my example tweeter is already much bigger compared to a dome
tweeter. It is a tweeter, not a fullrange ribbon.
Large radiating area is interesting, as long as the motion is kept
under control and there is no breakup.
The stators of an ESL can be kept rather thin and acoustically
"transparent" ore "pure resistive" that is true. With a magnetostatic
device this is more difficult, because even modern magnets need some
space for themselves and their fixation in space.
If we look at Quad ESL 63
- which to me is one of the most valid speaker designs -
the size of the radiating area shrinks with increasing frequency
As far as i know there are two reasons to do that:
- Avoiding uncontroled breakup of the radiating area at the upper end and
- Controling the radiation pattern.
A radiating area with diameter 100 x Wavelength is not really needed
or useful but has to be curved to obtain a useful radiation pattern.
Discussion depends on the aims of construction: Tweeter or Fullrange.
Best Regards
Oliver
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Hi,
the reduction in membrane area serves the linearization of the frequency response in first case. Curving a panel serves a similar purpose. Breakup can´t be avoided with both techniques, as can´t be with any speaker relying on membranes, plasma maybe the only exemption. But both techniques take care of the distribution pattern, which a non-segmented flat stator does not and which I don´t regard as a good or uptodate-design.
Though the idea behind the complex circuitry of the Quads is a brilliant theory, the concept has major basic flaws and there is nothing gained by the tremendous effort, that a much simpler electrical segmentation with resistors only, can´t do equally well. The Quads are a masterpiece to learn from how certain things should be done and other certain things should not be done. The rings belong to the things that should not be done, imho. 😎
jauu
Calvin
the reduction in membrane area serves the linearization of the frequency response in first case. Curving a panel serves a similar purpose. Breakup can´t be avoided with both techniques, as can´t be with any speaker relying on membranes, plasma maybe the only exemption. But both techniques take care of the distribution pattern, which a non-segmented flat stator does not and which I don´t regard as a good or uptodate-design.
Though the idea behind the complex circuitry of the Quads is a brilliant theory, the concept has major basic flaws and there is nothing gained by the tremendous effort, that a much simpler electrical segmentation with resistors only, can´t do equally well. The Quads are a masterpiece to learn from how certain things should be done and other certain things should not be done. The rings belong to the things that should not be done, imho. 😎
jauu
Calvin
Hi,
calvin, can you point me to an ESL design, which has
all of the design features you prefer ?
Just some Links would be helpful.
Cheers Oliver
calvin, can you point me to an ESL design, which has
all of the design features you prefer ?
Just some Links would be helpful.
Cheers Oliver
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