sound quality isnt affected by the type of film enough to matter. In fact Kapton has better internal damping than polyester BUT again there are other factors like adhesive and foils mass that come into play and even then the results are all very similar within practical limits
Kapton does have MUCH better heat resistance than mylar (polyester film) and in my development work I always had to use kapton on the smaller drivers that didnt have the heat load spread out on a big area. The mylar filmed units would melt. Im not sure about "PET"? Is that really polyethelen Naptha?
Lobing is an ugly issue and getting the ribbons close to the planers is a big deal
I always just make my own thin ribbon to put at sides of a planer allowing me to get it very close
AND I do not like so called "line arrays" that use multiple indavidual drivers above about 2 khz. I want a liner ribbon all the way OR if indaviduals then use an odd number maybe 3 -5 total units about 10 -20 inchs in length each and setup so center of one of them is the center of line. This to avoid spaces between ribbons in line with ear height.
btw recent proto work shows a concentric ribbon between planers is superior and not by a small amount.
Kapton does have MUCH better heat resistance than mylar (polyester film) and in my development work I always had to use kapton on the smaller drivers that didnt have the heat load spread out on a big area. The mylar filmed units would melt. Im not sure about "PET"? Is that really polyethelen Naptha?
Lobing is an ugly issue and getting the ribbons close to the planers is a big deal
I always just make my own thin ribbon to put at sides of a planer allowing me to get it very close
AND I do not like so called "line arrays" that use multiple indavidual drivers above about 2 khz. I want a liner ribbon all the way OR if indaviduals then use an odd number maybe 3 -5 total units about 10 -20 inchs in length each and setup so center of one of them is the center of line. This to avoid spaces between ribbons in line with ear height.
btw recent proto work shows a concentric ribbon between planers is superior and not by a small amount.
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Gist of this topic from US Patent 6,104,825 (Thigpen): greater than 1 watt per square inch causes expansion problems with Mylar membrane (loss of tension and increased distortion, bowing from thermal expansion rate mismatch). Diaphragms over 100 square inches are normally fine.
polyethylene terephthalate
https://en.wikipedia.org/wiki/Polyethylene_terephthalate
PET is referred to by its common name, polyester . . . . Biaxially oriented PET (BOPET) film (including brands like "Mylar")
F***
you know i was this close to putting you on ignore list when you tried to lecture me on how to improve my writing style but in the end this is actually valuable information ...
it was also my experience in my previous internet life years ago here ... i had to endure an absurd amount of nonsense but in the end i received ONE comment that actually changed my mind about the system i was then designing ...
the comment was that i can't mix horns with arrays in the same system because arrays don't fall off in SPL at the same rate as point sources with distance ... when i read that i almost vomited ...
i then had to study arrays until i actually somewhat understood them ...
in the end, equipped with better knowledge, i was able to make adjustments to the system to still make it work but never the less the comment was still valuable ...
this is why i also like to spew random information nobody asked for because you never know which information actually ends up being of value to somebody ...
i just teach people everything i know that they don't whether they asked for it or not ...
you can't wait for people to ask the right question - it will never happen
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I feel honored. Almost brings a tear to the eye.
I have protos of mid/tweet planers that have a concentric tweeter rather than to the side.
With the concentric I can get away with a 10-12 inch wide planer crossed at 3khz and get good results at seat. With the tweeter at the side of the wide planer I need to take tweeter down to about 1 khz to get same subjective performance. This with speaker parallel to back wall wich I like better than toed in when using dipole . Stage is bigger and speakers disappear better.
Point is the concentric is very forgiving of speaker position and crossover point with this wider diaphragm (desirable to take mid section down to 2-300Hz) and it all just seems to be a more stable image than side mounted. I suppose if the planer was less wide overall and the tweeter mounted close by its not an issue BUT I wanted a larger planer so can go solid to 300hz so it needed to be bigger and the concentric does better
i'm sure it's great i just don't understand what you mean by "concentric"
can you post a picture ? perhaps i am looking at wrong photos in the thread you linked but i am not understanding.
Ask the man how much his system costs
https://www.sympho-tech.it/index.php/prodotto/
It's all proprietary, the panels should contain many drivers
https://www.sympho-tech.it/index.php/prodotto/
It's all proprietary, the panels should contain many drivers
check the pics in the Open Baffle thred
its just a simple planer with the center traces taped to run as a separate tweeter
its works surprisingly well
However
Running the panel full range no tweeter (very narrow listening window) IMO beats it soundly . better imaging, more dynamic, more convincing you are there type sound etc etc. To my ears the large flat beamy panel always wins
I will likely be building the next one as a curved panel to see if it will retain the flat panels superior sound but with just a bit better dispersion. I suspect there will be a tradeoff
that's what i thought but of course i am unable to do this as i am not designing my own drivers.
it sounds like you are limited in your crossover. the real way to improve your driver may actually be by using DSP.
how about just make it a 3-way planar with DSP ?
you can only curve the panel so much ?
i listened to martin logan electrostatics with curved panels and they sounded nice but the panel is only barely curved ...
i mean as a thought experiment let's curve it all the way into a tube - how will that work ? the tube will have to expand and contract somehow - but how will it remain under tension doing this ? maybe you will need to introduce creases into it to allow it to expand ...
if you only curve it as much as martin logan does then it seems it would still beam quite a bit ...
actually i think AMT may be a better candidate for curving because it already has creases so you can curve it into a half tube and it would work exactly the same as when flat but now it would have perfect 180 degree dispersion.
actually do all 3 !
do a 3-way DSP planar, a curved planar with creases and a curved AMT !
if had the freedom to design my own drivers like you do i would build a compression driver with an annular diaphragm and a V-Dosc style phase plug that goes from ring directly to slot bypassing the unnecessary middle step of going through a round hole which exists purely for legacy reasons of compatibility. i would then array them. it would outperform everything that has ever existed by a wide margin.
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another thing you should do @lowmass is make a 3-way curved DSP planar BUT don't use constant radius curvature !
instead make the curvature tighter in the center where the tweeter is and then gradually reduce the curvature towards the edges where the mids are
this way the center portion is optimized for wide directivity of HF and the sides are optimized for large linear displacement
then tune everything in DSP
i have an even more genius idea for you @lowmass !
to maintain constant tension on a curved planar inflate it like a baloon using a very small DC air pressure maintained by some kind of servo pump
this way you could curve it all the way to like 180 degrees without having the diaphragm collapse on itself on the in stroke
instead of tensioning it from top and bottom it would be tensioned on the sides using some kind of latex-like surround
also the diaphragm would have corrugations in the kapton to allow for expansion but have latex-like strips connecting across these corrugations to maintain tension
make a 6" wide and 90 inch tall such driver with perhaps 120 degree curve and flank it by arrays of 8" woofers on both sides. 300 hz XO.
to maintain constant tension on a curved planar inflate it like a baloon using a very small DC air pressure maintained by some kind of servo pump
this way you could curve it all the way to like 180 degrees without having the diaphragm collapse on itself on the in stroke
instead of tensioning it from top and bottom it would be tensioned on the sides using some kind of latex-like surround
also the diaphragm would have corrugations in the kapton to allow for expansion but have latex-like strips connecting across these corrugations to maintain tension
make a 6" wide and 90 inch tall such driver with perhaps 120 degree curve and flank it by arrays of 8" woofers on both sides. 300 hz XO.
anyway version 3.0 is coming in a separate thread ... it's already designed ...
but first i want to describe version 2.5 and why it won't happen ...
in 2.5 we simply replace 10" radian with an array of 2" Morel dome mids
https://www.parts-express.com/Morel-MDM-55-2-1-8-Soft-Dome-Midrange-287-020?quantity=1
it has aluminum VC former for heat dissipation as well as aluminum chamber and a pretty beefy 6 mm tall by 2" diameter VC
best of all it has a small square flange so they can be stacked really tight ...
the problem is my very first speaker 25 years ago used a morel dome midrange ( except it wasn't a compact neodymium model ) ...
building my last speaker with the same component as the first somehow feels very wrong ... even though i was very happy with that dome ... but we all need to believe that in life we are moving forward and not going backwards - you know ?
so i'm just throwing that option out there for anybody interested in building line arrays since it was the best driver i could come up with for keeping the overall V2 configuration and simply replacing the midrange ...
but ultimately we are going to move to a new configuration
it's insane though that Morel is still making the same models of domes as i remember from High School ... they could have at least added a shorting ring or something in that 25 years ... or how about a fiberglass former with inside-outside wound VC ?
but morel is not a prosound company and audiophiles don't care about latest tech - they still use vacuum tubes FFS ...
anyway, see you in the V3 thread ...
but first i want to describe version 2.5 and why it won't happen ...
in 2.5 we simply replace 10" radian with an array of 2" Morel dome mids
https://www.parts-express.com/Morel-MDM-55-2-1-8-Soft-Dome-Midrange-287-020?quantity=1
it has aluminum VC former for heat dissipation as well as aluminum chamber and a pretty beefy 6 mm tall by 2" diameter VC
best of all it has a small square flange so they can be stacked really tight ...
the problem is my very first speaker 25 years ago used a morel dome midrange ( except it wasn't a compact neodymium model ) ...
building my last speaker with the same component as the first somehow feels very wrong ... even though i was very happy with that dome ... but we all need to believe that in life we are moving forward and not going backwards - you know ?
so i'm just throwing that option out there for anybody interested in building line arrays since it was the best driver i could come up with for keeping the overall V2 configuration and simply replacing the midrange ...
but ultimately we are going to move to a new configuration
it's insane though that Morel is still making the same models of domes as i remember from High School ... they could have at least added a shorting ring or something in that 25 years ... or how about a fiberglass former with inside-outside wound VC ?
but morel is not a prosound company and audiophiles don't care about latest tech - they still use vacuum tubes FFS ...
anyway, see you in the V3 thread ...
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yea lots of ideas
I have built smaller curved units in past, some were corrugated so they can move in-out a bit better and others with multiple flat sections. A true curve simply cannot move enough unless very large like the Martin Logans and that isnt my desire.
Thought about the "tube" design a few times but never went there. Would be an interesting experiment BUT past tests with these types of drivers in a box( the tube will need very carful damping internally like a box.) always left me deciding on sticking with open baffle dipole
The AMT is and likely always will be limited by the high main resonance of the pleat. By the time ya make the pleet deep enough to do lower freqs ya have serious issues. I considered a Teflon ( like thred seal type tape) diaphragm once (super supple and well damped to lower the Fs) But adhesives that work on teflon were outside my pay grade ha.
My work centers in an opposite direction than what you seem to be interested in. I thrill to simplicity in design whos performance outweighs its seemingly humble appearance . Loudspeaker design is a fun outlet for that disposition.
BTW the best sound I have ever heard was a very large true ribbon. True free swinging ribbon 2 inches wide, 5 feet tall, with large 4 foot wide baffle. Unpractical and inefficient but it was the most convincingly real sound I have ever heard. Even the bass was spectacular in a way nothing else has done. It seems a driver with almost none of the common speaker resonant activity and mass issues in the lower registers is the standard to judge by
I have built smaller curved units in past, some were corrugated so they can move in-out a bit better and others with multiple flat sections. A true curve simply cannot move enough unless very large like the Martin Logans and that isnt my desire.
Thought about the "tube" design a few times but never went there. Would be an interesting experiment BUT past tests with these types of drivers in a box( the tube will need very carful damping internally like a box.) always left me deciding on sticking with open baffle dipole
The AMT is and likely always will be limited by the high main resonance of the pleat. By the time ya make the pleet deep enough to do lower freqs ya have serious issues. I considered a Teflon ( like thred seal type tape) diaphragm once (super supple and well damped to lower the Fs) But adhesives that work on teflon were outside my pay grade ha.
My work centers in an opposite direction than what you seem to be interested in. I thrill to simplicity in design whos performance outweighs its seemingly humble appearance . Loudspeaker design is a fun outlet for that disposition.
BTW the best sound I have ever heard was a very large true ribbon. True free swinging ribbon 2 inches wide, 5 feet tall, with large 4 foot wide baffle. Unpractical and inefficient but it was the most convincingly real sound I have ever heard. Even the bass was spectacular in a way nothing else has done. It seems a driver with almost none of the common speaker resonant activity and mass issues in the lower registers is the standard to judge by
i believe you but "convincingly real sound" isn't my goal
my goal is to have mids like in a dance club, lows like in a car audio with aftermarket subwoofer and highs like a bullet supertweeter 3 feet in front of you
and to have all that as a coherent whole with a sweet spot wide enough that i can sit in a chair, lay on the couch, stand up or move around a few feet such as dancing etc.
a lot of the sound quality comes down to how something was recorded and the rest to what kind of substance you're under the influence of ... the goal of a speaker system is simply to never run out of steam when you ask for more and never break ( i can accept blown ribbons if they can be replaced ).
and by "when you ask for more" i mean at any given frequency. so it must be able to deliver as much as i ask equally at 30 hz and 16 khz and do so without me having to worry what will happen.
i can't enjoy music if i have to ask myself questions like "how much can i turn it up before i put my speakers in danger" any more than you can enjoy driving if you have to ask "how fast can i go before i get a ticket"
the only way to enjoy driving is to go as fast as you like without any concern for speed limits. some people want us to believe that some cars are more fun than others - that is BS. fun doesn't come from the car - but from how you drive it. the cheapest car at 3X the speed limit is more fun than a Lambo at speed limit.
this is why my focus is on SPL across the entire frequency range as well as on vertical and horizontal coverage ... basically the same criteria as what systems in prosound are designed for ...
because prosound guys actually do studies on what people enjoy and it isn't realism - it is loudness
🙂
and frankly "real" isn't even applicable to the kind of music i listen to, which is all electronic.