Hi i measured some panels for my ESL63 , and i discovered that original panels res (while under high voltage) is around 70 hertz.
now my question is. as far as i know they use the same panels in the ESL 63 ESL 988 and the 989 (i think even in the latest model) they all reach lower then the ESL63. but how ?>?>? ofc they got more surface area. but still they got a res around 70hz how can the 989 reach 40 hertz ? must be minus several dB. or did they just reconfigured there filters.
woukld be more effective if the panels of a 989 would have a res of around 40-50. but then again membrane stability could be a problem. and since everyone is just swapping them around. it looks like they are the same. anyone ever measured a single panel of a 989 or a 988 ?
now my question is. as far as i know they use the same panels in the ESL 63 ESL 988 and the 989 (i think even in the latest model) they all reach lower then the ESL63. but how ?>?>? ofc they got more surface area. but still they got a res around 70hz how can the 989 reach 40 hertz ? must be minus several dB. or did they just reconfigured there filters.
woukld be more effective if the panels of a 989 would have a res of around 40-50. but then again membrane stability could be a problem. and since everyone is just swapping them around. it looks like they are the same. anyone ever measured a single panel of a 989 or a 988 ?
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Are you measuring one panel by itself in free air? or mounted with the other panels in the baffle with all panels playing.
The airload increases significantly due to mutual coupling when several panels are mounted next to each other which will lower resonance frequency. The small baffle edges around the perimeter of the frame also increase the airload. I had posted a measurement in the AMT thread showing that adding baffle edges to a small panel lowered resonance by ~10%...mutual coupling has an even greater effect.
http://www.diyaudio.com/forums/planars-exotics/153220-electrostatic-amt-18.html#post1981871
According Baxandall ESL chapter and Walker AES paper, resonance frequency of the ESL63 panel array should be about 45 - 50 Hz.
http://www.diyaudio.com/forums/plan...range-electrostatic-question.html#post3965195
Hmm nice interesting bolsert as usually !
i measured 2 panels standing upright (free air), just for comparison for spl. i wanted my panels to be exactly as loud. (witch i managed thank god ) but the resonance of one original panel standing upright is 70 hz +- witch baffled me. but now this explains allot. its good to know it has to be around 70 when i test panels separately.
so a 989 uses 6 panels and resonance drops with 10 hz , thats why it can reach 40 instead of the 50 of the esl63
looks like it drops 5 hz with every panel added. at least this goes for 1 to 4 from 70 to 50 and as wel from 50 to 40 with 6 panels
i measured 2 panels standing upright (free air), just for comparison for spl. i wanted my panels to be exactly as loud. (witch i managed thank god ) but the resonance of one original panel standing upright is 70 hz +- witch baffled me. but now this explains allot. its good to know it has to be around 70 when i test panels separately.
so a 989 uses 6 panels and resonance drops with 10 hz , thats why it can reach 40 instead of the 50 of the esl63
looks like it drops 5 hz with every panel added. at least this goes for 1 to 4 from 70 to 50 and as wel from 50 to 40 with 6 panels
Something diff................bolsert .....can you help ?........if I have a tranfourmer running in a tube bais setup...........that has 120 ac primary side......an 6V output on the secdary side.......this tranfourmer can get vary warm..................
the bass tran in the 121interfaces.....or othere ESL ......like soundlabs....Ml.....well these trans ever get hot..................an still work?.................why??
thanks
the bass tran in the 121interfaces.....or othere ESL ......like soundlabs....Ml.....well these trans ever get hot..................an still work?.................why??
thanks
I think this might win a prize for most off-topic post
Transformers get hot because of power lost as heat in the windings:
Power loss = (winding resistance) * (current)^2
With power transformers like the 6V filament transformer you mentioned, the input voltage is a steady known value. So the transformer is usually designed to work within temperature ratings of the wire insulation using minimum amount of iron and copper to save money for the manufacturer. If they used more iron and/or copper the transformer would run cooler, but they wouldn't make as much money selling the transformer.
ESL transformers do not have a steady input voltage. Music has a large Peak/RMS ratio. Usually the ESL transformers are not designed to handle Peak output voltage for sustained periods of time. If you applied maximum peak output possible from music (40 - 50 Vrms @ 30Hz) for a sustained period of time the windings would burn up on the Acoustat bass transformer before you felt the core of the transformer getting warm. Fortunately music doesn't have this type of sustained voltages so the windings have time to cool off between bass peaks.
If you put in a steady lower voltage (15Vrms @ 60 Hz into the Acoustat bass transformers for an hour you would feel them getting warm.
Yes the panels is the same.
Thats why i have 9 pairs esl63 in the basement
Electrically no cange, different layout on the circuit boards. Better?
No.. I would guess worse.
In Esl 63 the HV circuit board was dipped in Bees wax to get ridge of creepage currents.
Works fine even in humidity. Today they have increased the distances between the components, better? I doubt.. cheeper yes.
Mechanically the new ones is much much more rigid and better. But to increase the stiffness of the 63s is not that difficult. Resonance. Each panel has a wery fine mesh which have a huge impact of the resonance Q value. I know of no other electrostatic speaker with this feature.
Thats why i have 9 pairs esl63 in the basement
Electrically no cange, different layout on the circuit boards. Better?
No.. I would guess worse.
In Esl 63 the HV circuit board was dipped in Bees wax to get ridge of creepage currents.
Works fine even in humidity. Today they have increased the distances between the components, better? I doubt.. cheeper yes.
Mechanically the new ones is much much more rigid and better. But to increase the stiffness of the 63s is not that difficult. Resonance. Each panel has a wery fine mesh which have a huge impact of the resonance Q value. I know of no other electrostatic speaker with this feature.
I agree that the vast majority of ESLs have little if any damping. Obviously the Acoustat’s thick felt stator pads provide acoustic damping of the diaphragm resonance, although not in as elegant a manner as with the Quads. Some of the STAX full range ESLs used mesh similar to Quad although the weave wasn’t as tight and the mesh was attached on the outside of both stators. (attached pic of ELS-F81)
But, you are probably talking about current production.
The only other manufacturers that I know of that use damping is JansZen and PIO Sound.
Here are some quotes I pulled from the JansZen website.
“…You might be familiar with see-though ESL's, but these and most other non-JansZen ESL's are similar to one another, in the sense that the membrane motion is not damped. Our membranes, however, have just the right amount of damping….”
“…To prevent natural membrane resonances from coloring the sound, it is important to provide acoustical membrane damping. Many ESL's use a see-though design that increases loudness at the expense of resonant coloration, as well as inviting intermodulation distortion during resonant excitations. In JansZen ESL's, membrane resonances are fully damped…”
PIO Sound is actually trying to get a patent on using the mesh for damping ESL diaphragm resonance.
Brochure, review, and patent application attached.
Attachments
It depends on what the load on the secondary is at the frequency you are driving the transformer with. For the Acoustat, at low frequencies (ie < 100 hz) the load on the secondary of the LF transformer from the mixer and HF transformer would by drawing less than 20mA, so even at worst case the secondary winding would be dissipating less than 1 watt of heat. At higher frequencies the current thru the secondary and heat dissipated will increase because the impedance of the capacitive part of the load decreases.
In the case of your filament transformer, the secondary will likely be dissipating as much if not more heat than the primary is all the current running through the filaments will be passing through the secondary.
I agree that the vast majority of ESLs have little if any damping. Obviously the Acoustat’s thick felt stator pads provide acoustic damping of the diaphragm resonance, although not in as elegant a manner as with the Quads. Some of the STAX full range ESLs used mesh similar to Quad although the weave wasn’t as tight and the mesh was attached on the outside of both stators. (attached pic of ELS-F81)
But, you are probably talking about current production.
The only other manufacturers that I know of that use damping is JansZen and PIO Sound.
Here are some quotes I pulled from the JansZen website.
“…You might be familiar with see-though ESL's, but these and most other non-JansZen ESL's are similar to one another, in the sense that the membrane motion is not damped. Our membranes, however, have just the right amount of damping….”
“…To prevent natural membrane resonances from coloring the sound, it is important to provide acoustical membrane damping. Many ESL's use a see-though design that increases loudness at the expense of resonant coloration, as well as inviting intermodulation distortion during resonant excitations. In JansZen ESL's, membrane resonances are fully damped…”
PIO Sound is actually trying to get a patent on using the mesh for damping ESL diaphragm resonance.
Brochure, review, and patent application attached.
nice speakers to look at. but nothing new here indeed
except for the cardiod dipole sub :0 never seen that combination before through. measurements seem bit crude immense dip at 2 khz :0heeey is this an inverted esl, they talk about carbon nano fibres etc... wont be needed if it was a normal one
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Correct. The PIO ESLs use the inverted drive arrangement.
I guess this shouldn't much of a surprise since PIO is the latest company of the FINAL designer.
Quote from the White Paper:
“With the PIOSound ADS technology the converted audio signal is fed to the diaphragm or membrane through a proprietary electrical module which uses a new and innovative transformer technology while a high voltage + and – DC signal is applied on the stator plates.”
aha thought it had more distortion this way.. to work well resistance on foil must be as low as possible?. segmentation is done then on the membrane. hmm well hopefully there coating is better this time
or they are sold all broken on second hand web pages again.Dennesen tweeters, designed in some partnership with Jansen* of JansZen decades ago, also have some amount of light paper towel stuff pasted behind the rear stator for higher-frequency damping.
These cells are clever devices, 4-inch disks with the stator made by winding a wire round and round. I've always thought the fast-track to making DIY ESLs is to find plastic forms (like fluorescent lamp covers) to serve as the stators.
Ben
*got his training at MIT under Hunt who conceived the basic ESL analysis long ago.
These cells are clever devices, 4-inch disks with the stator made by winding a wire round and round. I've always thought the fast-track to making DIY ESLs is to find plastic forms (like fluorescent lamp covers) to serve as the stators.
Ben
*got his training at MIT under Hunt who conceived the basic ESL analysis long ago.
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![DSC06910[1].jpg](/community/data/attachments/477/477570-5e24a526fae74feb87f751cfec94ac73.jpg)
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