Hi Oliver,
I guess the corrugation we talk about doesn`t have to be deep at all. One could make three corrugations at the centre of the foil and when you attach the ribbon to the frame, the foil will tend to straighten itself again, but the slight corrugation ribs will remain and ensure the stabilizing effect over it`s shape, during the motion. As for the mylar reinforced corrugations at both ends of the ribbon, I only wanted to ensure some elasticity of such "suspension" and to avoid ageing of the pure stretched flat ribbon, but then again I am not sure if this would be necessary at all, since planar magnetics don`t have any suspension either (just a foil stretched onto a frame) and are used down to the mid frequencies. I don`t know, perhaps I am completely wrong...
Best regards
I guess the corrugation we talk about doesn`t have to be deep at all. One could make three corrugations at the centre of the foil and when you attach the ribbon to the frame, the foil will tend to straighten itself again, but the slight corrugation ribs will remain and ensure the stabilizing effect over it`s shape, during the motion. As for the mylar reinforced corrugations at both ends of the ribbon, I only wanted to ensure some elasticity of such "suspension" and to avoid ageing of the pure stretched flat ribbon, but then again I am not sure if this would be necessary at all, since planar magnetics don`t have any suspension either (just a foil stretched onto a frame) and are used down to the mid frequencies. I don`t know, perhaps I am completely wrong...
Best regards
Hi,
@LineArray
Mine of course
http://www.diyaudio.com/forums/showthread.php?s=&threadid=124282
Naaa, just kidding....or? 😉
Conceptually I think the ML Statement and even more the StatementII were very close to optimum. But both of rather impractical build size and price. Both with curved stators. In the DIY-segment I find the Capaciti very well made, which feature segmented planar stators.
Against many, I´m of the opinion that a Hybrid-ESL can be made with a seamlessly integrated bass. If done so You benefit from the superior qualities of the dynamic drivers in the bass region like compactness, ease of drive, higher linearity and lower distortion.
From the bass on upwards there´s nothing that imho comes close to a ESL. Linearity, distortion, resolution, naturalness are just a few points to name.
jauu
Calvin
@LineArray
Mine of course
http://www.diyaudio.com/forums/showthread.php?s=&threadid=124282
Naaa, just kidding....or? 😉
Conceptually I think the ML Statement and even more the StatementII were very close to optimum. But both of rather impractical build size and price. Both with curved stators. In the DIY-segment I find the Capaciti very well made, which feature segmented planar stators.
Against many, I´m of the opinion that a Hybrid-ESL can be made with a seamlessly integrated bass. If done so You benefit from the superior qualities of the dynamic drivers in the bass region like compactness, ease of drive, higher linearity and lower distortion.
From the bass on upwards there´s nothing that imho comes close to a ESL. Linearity, distortion, resolution, naturalness are just a few points to name.
jauu
Calvin
Calvin said:
Hello Clavin,
Interesting , quick question , have you ever tested your ESl and if so what are you using to do so .
Re: Re: ribbons vs electrostats
I agree with most of what was said, with a few exceptions. Corrugation of the ribbon element is mostly determined by size and use. Different methods of corrugation will help in controlling resonance in the audio bandwidth being used . Going flat on a thin High freq ribbon will work and work well , will not do so on a 1.5 inch width foil running a wide bandwidth. Corrugation can be extremely extremely rigid to a moderate fold but running flat on a large ribbon going below 800 hz will suffer from resonance issues, distorting the sound. Some corrugation will be required if for no more than to move the resonace frequency.
AW
LineArray said:
I agree with most of what was said, with a few exceptions. Corrugation of the ribbon element is mostly determined by size and use. Different methods of corrugation will help in controlling resonance in the audio bandwidth being used . Going flat on a thin High freq ribbon will work and work well , will not do so on a 1.5 inch width foil running a wide bandwidth. Corrugation can be extremely extremely rigid to a moderate fold but running flat on a large ribbon going below 800 hz will suffer from resonance issues, distorting the sound. Some corrugation will be required if for no more than to move the resonace frequency.
AW
Hi,
of course wayne, have the panels as well as the complete speakers been tested. 🙄
Starting from quickanddirty measurements with an DLSA (cheap mic) over DAAS32 (with MB550 mic) up to MonkeyForest (with 1/4" and 1/2" B&K mics).
Measurements we did ourselves and measurements in the big measuring room (low reflectivity) of the University Aachen (measured by Anselm Goertz, who undoubtly knows how to measure things correctly 😉 )
Both speakers exhibit extremely low distortion values. The big one measured lower than 0.2% in its complete frequency range (25Hz-20kHz) at a SPL of 95dB@4m. The small panel limits at 110dB@4m thereby measuring less than 0,3%THD over its working range (200Hz-20kHz). The THD values consist of nearly solely K2.
A typical measurement of SPL values is done at a distance of just 1m. For a 4m distance measurement 12dB should be added.
These are extremely low distortion values (You have to keep in mind that the measuring setup itself introduces a certain level of distortion. Distortion measurements with the DAAS32 and MB mic showed higher -still though comparably low- values, but prooved the MB mic to distort more than the B&K capsules and already more than the speaker itself.
The values found are much lower than You can reach with electrodynnamic drivers exempt maybe some big horns but those are very limited in bandwidth. The 110dB@4m of the smaller panel are very close to the maximum SPL that can be reached theoretically with a panel of this size anyway!
So I guess that my panel construction and the build quality are on a niveau that allows to draw conclusions about what a good panel might be able to 😉
Ohh, btw. to return to the question 😉 The speakers have been extensively tested by many ears too. And all of them have seemed to like the sound alot 😎 At least the one who declares that he/she dislikes the sound has not spoken to me yet.
jauu
Calvin
ps
Anyway...I can just encourage You to put effort and time into a ESL project. Done well this principle is indeed very rewarding. The chances of ever returning to the unnatural, smeared and restricted sound of typical electrodynamic boxes is rather low.
of course wayne, have the panels as well as the complete speakers been tested. 🙄
Starting from quickanddirty measurements with an DLSA (cheap mic) over DAAS32 (with MB550 mic) up to MonkeyForest (with 1/4" and 1/2" B&K mics).
Measurements we did ourselves and measurements in the big measuring room (low reflectivity) of the University Aachen (measured by Anselm Goertz, who undoubtly knows how to measure things correctly 😉 )
Both speakers exhibit extremely low distortion values. The big one measured lower than 0.2% in its complete frequency range (25Hz-20kHz) at a SPL of 95dB@4m. The small panel limits at 110dB@4m thereby measuring less than 0,3%THD over its working range (200Hz-20kHz). The THD values consist of nearly solely K2.
A typical measurement of SPL values is done at a distance of just 1m. For a 4m distance measurement 12dB should be added.
These are extremely low distortion values (You have to keep in mind that the measuring setup itself introduces a certain level of distortion. Distortion measurements with the DAAS32 and MB mic showed higher -still though comparably low- values, but prooved the MB mic to distort more than the B&K capsules and already more than the speaker itself.
The values found are much lower than You can reach with electrodynnamic drivers exempt maybe some big horns but those are very limited in bandwidth. The 110dB@4m of the smaller panel are very close to the maximum SPL that can be reached theoretically with a panel of this size anyway!
So I guess that my panel construction and the build quality are on a niveau that allows to draw conclusions about what a good panel might be able to 😉
Ohh, btw. to return to the question 😉 The speakers have been extensively tested by many ears too. And all of them have seemed to like the sound alot 😎 At least the one who declares that he/she dislikes the sound has not spoken to me yet.
jauu
Calvin
ps
Anyway...I can just encourage You to put effort and time into a ESL project. Done well this principle is indeed very rewarding. The chances of ever returning to the unnatural, smeared and restricted sound of typical electrodynamic boxes is rather low.
Re: Re: Re: ribbons vs electrostats
Hi a.wayne ,
maybe a am somewhat blind but i cannot see any conflict with
what i said. I agree fully with your observations concerning
the need and the use of corrugation.
When used fairly above the resonant frequency and higher
excursion is not needed (due to diaphragm size), a
flat foil might perform very well.
In my own ribbon design i introduced that corrrugation mainly
because i wanted to get down to 800Hz with an 8mm wide
diaphragm thereby keeping a controlled motion.
Best Regards
a.wayne said:
Hi a.wayne ,
maybe a am somewhat blind but i cannot see any conflict with
what i said. I agree fully with your observations concerning
the need and the use of corrugation.
When used fairly above the resonant frequency and higher
excursion is not needed (due to diaphragm size), a
flat foil might perform very well.
In my own ribbon design i introduced that corrrugation mainly
because i wanted to get down to 800Hz with an 8mm wide
diaphragm thereby keeping a controlled motion.
Best Regards
Calvin said:
LOL.
Calvin .2% THD ( 25-20K) forgive me for having a hard time in accepting that. I'm sure you and others enjoy the sound of your speakers, audio and subjectivity goes hand in hand , scratching for objectivity is the real nirvana in audio . TO say you have an ESL speaker that has .2% THD from 25-20K is unheard off on this planet or any other that i have visited in the last 10 eons, I guess you are being tongue in cheek. 😀 if not, then they are not an ESL , but more likely some Clingon verberator running on pulsewidth germainium.
High efficiency DIY ribbons use 0.5" to 1" wide NdFeB magnets to create 0.5T-1T flux in the gap. What is the best solution to minimize these magnet cavity effects on a true ribbon?
Any experience or measurements with "waveguide type" front bezel curves, or RAAL type "triangle cut" bezel plates?
------------------------------------
www.transmissionaudio.com posts "extremely low" distortion measurements for ribbons
LaScala, our top-of-the-line full-range true ribbon speaker.
Total radiating area, one speaker only: 9500 sq. centimeters = 3,740 sq. in.
Whereof: LF/MID = 9000 and HF=500 square centimeters respectively.
Max SPL for any frequency within 30Hz to 30kHz: Limited by Xmax only.
Total height: 220 cm (86 in.) Total width: 95 cm (37.4 in.)
Number of 2" wide ribbons: 9. Number of 1" wide ribbons: 1
Total ribbon length: 20 meters (787 in.).
Total magnet line length: 22 meters (866 in.)
Sensitivity: Ultra Propulsion mode: 90dB/1W/1meter;
System resonance: 4Hz.
Impedance: 8,0 Ohm at any frequency 10Hz to 40kHz (Ultra Propulsion mode);
Distortion: typically 0,05% at 110dB SPL.
Any experience or measurements with "waveguide type" front bezel curves, or RAAL type "triangle cut" bezel plates?
------------------------------------
www.transmissionaudio.com posts "extremely low" distortion measurements for ribbons
LaScala, our top-of-the-line full-range true ribbon speaker.
Total radiating area, one speaker only: 9500 sq. centimeters = 3,740 sq. in.
Whereof: LF/MID = 9000 and HF=500 square centimeters respectively.
Max SPL for any frequency within 30Hz to 30kHz: Limited by Xmax only.
Total height: 220 cm (86 in.) Total width: 95 cm (37.4 in.)
Number of 2" wide ribbons: 9. Number of 1" wide ribbons: 1
Total ribbon length: 20 meters (787 in.).
Total magnet line length: 22 meters (866 in.)
Sensitivity: Ultra Propulsion mode: 90dB/1W/1meter;
System resonance: 4Hz.
Impedance: 8,0 Ohm at any frequency 10Hz to 40kHz (Ultra Propulsion mode);
Distortion: typically 0,05% at 110dB SPL.
Attachments
High efficiency DIY ribbons use 0.5" to 1" wide NdFeB magnets to create 0.5T-1T flux in the gap. What is the best solution to minimize these magnet cavity effects on a true ribbon?
Any experience or measurements with "waveguide type" front bezel curves, or RAAL type "triangle cut" bezel plates?
Any experience or measurements with "waveguide type" front bezel curves, or RAAL type "triangle cut" bezel plates?
Attachments
When using "conventional" ribbon shape the answer is
simple: The problem stays.
Both solutions you mention (sawtooth border of front bezel,
wave guide) seem applicable to deal with that.
Maybe covering the magnet/bezel using soft and porous
materials can help too.
I used a waveguide in my own design once and was not
statisfied with the result.
I heard the Crevasse at an audio fair some years ago.
To me it sounded rather warm and balanced in the
midrange but also dull in the highs.
There was a lack of resolution and "dircectness" which
made me wonder why to use a ribbon at all ... But i do not
think that the waveguide/horn was responsible for that.
Although it is a very impressive and aesthetical design
to me, but was one of the greatest disappointments
sonically.
With a different transducer design i think there would be
higher potential. Maybe they changed somewhat in the last
years, i don't know. The Crevasse transducer that i have seen
had more than one conducting lane on its diaphragm,
so we can discuss if it is still a "true ribbon".
I don't like the term "true ribbon" by myself, but if used i would
apply it to those constructions, which have only one conducting
lane, which is the made of the diaphragm material itself.
Personally i would not bind "truth" to the way the ribbon
is suspendend/folded/currugated.
To overcome/attenuate the protruding magnets by transducer
design, like i explained before, is the way to solve
the problem at its roots IMO.
simple: The problem stays.
Both solutions you mention (sawtooth border of front bezel,
wave guide) seem applicable to deal with that.
Maybe covering the magnet/bezel using soft and porous
materials can help too.
I used a waveguide in my own design once and was not
statisfied with the result.
I heard the Crevasse at an audio fair some years ago.
To me it sounded rather warm and balanced in the
midrange but also dull in the highs.
There was a lack of resolution and "dircectness" which
made me wonder why to use a ribbon at all ... But i do not
think that the waveguide/horn was responsible for that.
Although it is a very impressive and aesthetical design
to me, but was one of the greatest disappointments
sonically.
With a different transducer design i think there would be
higher potential. Maybe they changed somewhat in the last
years, i don't know. The Crevasse transducer that i have seen
had more than one conducting lane on its diaphragm,
so we can discuss if it is still a "true ribbon".
I don't like the term "true ribbon" by myself, but if used i would
apply it to those constructions, which have only one conducting
lane, which is the made of the diaphragm material itself.
Personally i would not bind "truth" to the way the ribbon
is suspendend/folded/currugated.
To overcome/attenuate the protruding magnets by transducer
design, like i explained before, is the way to solve
the problem at its roots IMO.
Hi,
@wayne
Could you please stop citing complete texts? 😡
Sorry, that I don´t lough along with you.
I could understand your reaction if I had ´faked´ the measurement myself. But no, the measurement was executed by Prof.Dr. A.Goertz who is a well known capacity within the audio-scene and it took place on may, 19th. 2008 in the anechoic room at the RWTH Aachen which is one of the top universities in Germany for electronics and acoustics.
And simply because of You haven´t seen or heard of a speaker that performs so well doesn´t mean it doesn´t exist. I and all those who saw and heard it yet, know it exists. 😀
jauu
Calvin
@wayne
Could you please stop citing complete texts? 😡
Sorry, that I don´t lough along with you.
I could understand your reaction if I had ´faked´ the measurement myself. But no, the measurement was executed by Prof.Dr. A.Goertz who is a well known capacity within the audio-scene and it took place on may, 19th. 2008 in the anechoic room at the RWTH Aachen which is one of the top universities in Germany for electronics and acoustics.
And simply because of You haven´t seen or heard of a speaker that performs so well doesn´t mean it doesn´t exist. I and all those who saw and heard it yet, know it exists. 😀
jauu
Calvin
LineSource said:
LineArray said:
Linearray ,
I can concur with what you say, as we did come to the same conclusion. We ended up using a very short wave guide which helped, but did have a very slight change in directivity , we did pick up 1.8 db gain. and felt the gains outwayed the negative.
With a longer wave guide as illustrated above , our conclusions where the same as yours , it destroyed the sound of the speakers. What also helped was adding wings recessed 1 inch behind the front baffle and at an 'angle of no more than 45 Deg. Anything above this picked up more gain but at the expense of becoming a monolith and had too much boundary effect making the speaker less able to Image , less likely to "disappear".kinda like a big ESL where the image size is big all the time reduced dynamics ( micro and macro)
Calvin ,
Relax , I 'm here to have fun and for mutual technical exchange . No offense was intended , I do apologize if you took it differently.
My intentions was not directed @ Goertz or his testing facility , just saying regardless of how you put it . i have a hard time believing you have a speaker that has .2 % THD when measured from 25-20 k. Could you please post your SPL Sweep or any data from the lab... it would help me come up to speed as to where you are with your ESL.................
A.Wayne
RAAL's "raindrop" tweeter designed to be crossed over 3,000 Hz uses a "waveguide" type bezel for diffraction and directionality control instead of the sawtooth metal front bezel of their higher volume ribbons which are spec'ed for 1,500 Hz crossover.
Would the raindrop waveguide be a more expensive solution that can reduce distortion over the lower cost sawtooth bezel, or.....
The raindrop waveguide bezel might be used to increase SPL to match a compression horn efficiency.
The raindrop waveguide bezel might be used to better match the directionality of the horn tweeter.
A sawtooth bezel would be the easiest solution if it also produced the best sound with deep magnetic cavity ribbons.
Waveguide vs. sawtooth bezel is still the good-better-best question.
Would the raindrop waveguide be a more expensive solution that can reduce distortion over the lower cost sawtooth bezel, or.....
The raindrop waveguide bezel might be used to increase SPL to match a compression horn efficiency.
The raindrop waveguide bezel might be used to better match the directionality of the horn tweeter.
A sawtooth bezel would be the easiest solution if it also produced the best sound with deep magnetic cavity ribbons.
Waveguide vs. sawtooth bezel is still the good-better-best question.
Attachments
a.wayne said:
The Quad ESL63, build in the 80s, has distortion <0.1% from 150Hz upward. So it's not that unbelievable.
@Calvin:
Sounds like a great speaker, and the big one looks awesome too! Congratz. It takes a lot of time, effort and expense to build a speaker like that. I hope to hear it some day.
(P.S. The quote of the quad distortion is not ment as a piss ing contest.)
Hi,
I´ll try to get my fingers on the measurement data but it may take some time.
Of course I was very astonished too when A.Goertz pointed towards the monitor and asked us to have a look. I expected low distortion values for the panel, but did not equally expect them for the bass too, because its rumoured that a dipole couldn´t perform as well in this department as other principles because of the necessary larger excursions. But using 8 drivers per side and drivers with a lot of copper in the magnetic circuit seems a good starting point. Anyway, I doubt that it makes any audible difference between 0.2% and 2% of distortion in the bass.
For the capabilities of the panel... I´m not at all astonished to see such low values for ´modest´SPLs. The astonishment rather comes when there are still lowest distortion values at SPLs >100dB!
Besides precise execution of the panel build this mainly shows the high quality of the used audio transformers.
jauuu
Calvin
I´ll try to get my fingers on the measurement data but it may take some time.
Of course I was very astonished too when A.Goertz pointed towards the monitor and asked us to have a look. I expected low distortion values for the panel, but did not equally expect them for the bass too, because its rumoured that a dipole couldn´t perform as well in this department as other principles because of the necessary larger excursions. But using 8 drivers per side and drivers with a lot of copper in the magnetic circuit seems a good starting point. Anyway, I doubt that it makes any audible difference between 0.2% and 2% of distortion in the bass.
For the capabilities of the panel... I´m not at all astonished to see such low values for ´modest´SPLs. The astonishment rather comes when there are still lowest distortion values at SPLs >100dB!
Besides precise execution of the panel build this mainly shows the high quality of the used audio transformers.
jauuu
Calvin
Hi,
ohh come on AJ. 🙄 Feel free to eat whatever you like, but don´t expect answers to each and every detail of a commercial product. Just so much: the trannies are tailor made to our specifications.
jauu
Calvin
ohh come on AJ. 🙄 Feel free to eat whatever you like, but don´t expect answers to each and every detail of a commercial product. Just so much: the trannies are tailor made to our specifications.
jauu
Calvin
Hi Calvin,
I did not know it is a commercial product (I know Capacity is commercial). Anyway, since you mentioned the transformers specifically on a DIY forum, I did not realise when we're not allowed to ask anything about them. I can't see the harm done, but will refrain from asking anything about your speaker in the future.
I did not know it is a commercial product (I know Capacity is commercial). Anyway, since you mentioned the transformers specifically on a DIY forum, I did not realise when we're not allowed to ask anything about them. I can't see the harm done, but will refrain from asking anything about your speaker in the future.
On review, my post may seem a little harsh. This was not my intention (maybe has to do with a serious hangover after the Dutch football celebration last night 🙂
Hi,
and you were really entitled to do so!
What a brilliant game they played. 😀
It was a pleasure to watch.
jauu
Calvin
and you were really entitled to do so!
What a brilliant game they played. 😀
It was a pleasure to watch.
jauu
Calvin
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