You could buy big electrostatic speakers over 40 years ago. They were half the size of a door, and sounded really good. For some reason, maybe too high a price, they never really caught on. They should have a very good frequency response, if made properly. Another option was the crystal earpiece, using a piece of Rochelle salt between two electrodes. Very beloved as crystal radio receiver earpieces. You've set the mind ticking, Robert. Thank-you!
I make ESLs for a hobby. You can make good sounding esls and construction is simple. Actually graphene would not be the best coating as charge has to be static. But you may use graphene to make stators conductive. Have fun with esls.
@@AdityaMehendale ; you will have 2 stators with the film in between. It is a pushpull system with very low distortion. High voltage is put on the film. It is generated bt a cascade circuit. I know a guy who used the high voltage output of an electric mosquito killer.
@@AdityaMehendale Well I think Robert has made an ESL just for the fun of showing that it can make sound. I cant see how this kind of construction can keep up with the conventional, free moving pushpull esl.
I think you need some sort of a fixed high voltage DC bias with the audio signal superimposed on it, otherwise the sound will suffer a frequency doubling (severe distortion). As the speaker is voltage driven, and the current is negligible, I would also doubt there would be any advantage in using your highly conductive coating on the plastic - a poor one would be equally effective.
Form you description the "flyback transformer" seems to take a DC input and produce an alternating output hence the terrible distortion. It will only turn on on half of the audio cycle and only above some threshold. When I was a kid I had a valve record player and that had a normal loud speaker plus an electrostatic tweeter. I think the tweeter was just connected to primary of the output transformer, so only perhaps 100V swing, not 40kV.
I was thinking for your lab more than myself but I do want to start marking it so getting properly set up would be smart , I ordered ferric chloride stuff but got it in liquid form and after reading comments again I realized I should have got it in powder form, could I dry it to make it the same as powdered like you used although the permanganate way seems a good option I had another thought a few weeks back about fine tuning an ultrasonic bath to emit the resonance frequency of graphite and seeing your speaker video tonight , I wondered if you have thought of it or even tried it yourself , seems plausible but I can’t imagine no one hasn’t thought of it before so maybe it doesn’t help split the graphite but if it helped it could be handy Is tony still working with you on concrete development Great job as always thanks a million for everything you share Edit, This was meant to be a reply about the fume cupboard comment I made on your earlier video
Now if you held the small frame over a vented box your sound would be louder Thats why placement away from walls is critical with stats. However with the woofer id do a a periodic membrane over the front of the driver to load it down that way id get reflective bass sound off the low-end driver.
The impedance mismatch between the amplifier and the transformer is causing the distortion in the speaker .That poor transformers primary is getting saturated
Are you sure the graphene diaphragm is thin enough? Thicker material results in truncated high frequencies. I've heard this problem with an overly thick mylar diaphragm installed on a bad sample of an "Audiostatic" speaker. Extreme roll off of highs was the result while other samples of the same speaker with the right mylar sounded just fine. Unless the membrane is sufficiently thin you'll never hear the detail and transparency an electrostatic is capable of. And that graphene looks way too thick for such an application. Martin Logan diaphragms are typically about .0005 inch or 10 microns thick.
Hi ROB another great video, how about adding 4-5 mega ohms resistor in parallel and cut the sheets in a circular shape and at the far opposite side to adding an high voltage arrester then volume should be attenuated till you get the best performans not at the highest set.,keep the good work bro cheers mate .
If you cut out the centre of a sweet tin lid and force fit the sheets between would it amplify better? There's a covering for model aircraft called solar film,iron on adhesive,shrinks with heat,could it be grapheneated?
I am sure you could - have a look at commercial versions and see where they differ - build quality is on issue but to get this working I roped together some pretty basic electronics - a dedicated driver board would certainly improve it
@@ThinkingandTinkering this was used as a cheap tweeter in the early days of audio...in order to get push-pull sound , screens w/bias voltage are needed electrostatic speakers have been considered among the most accurate , but they're complicated for the home builder..... plans were available through the 50's ( AUDIO magazine) , and SPEAKER BUILDER in the 70's this reply to Archie also , because sound is degraded by enclosing an ESL , they are nearly always used as dipoles , so must be LARGE .....i dreamed for yrs. of bldg. a folding screen ESL , but never got around to it
@@ThinkingandTinkering tension your diaphragm to a frame. force used is proportional to voltage required. the buzzing sound comes from the plastic hitting stuff. if you insist on improving the driver circuit, look up schematics of old stax amplifiers. more info (200+ page thread on head-fi): google "diy electrostatic headphones"
@@kcajmortsnnew1488 you should have done - it is always a lot of fun to actually DO something rather than just talk about it - you learn so much from doing is my feeling. You are quite right to create high fidelity reproduction is a challenge but to explore the science behind it and have fun is pretty easy - positive mental attitude mate lol
@@michaelknight2342 insist? mate this is just fun to do -I don't really want to be a pedant as you are kind of right but I always thought that the force used was proportional to the mass of the membrane you are trying to vibrate and the square of the distance the membranes are apart. The strength of the field required to do that work was, i always thought, proportional to the voltage applied
Who needs a separate phone screen and speaker when the screen can be the speaker. I wonder if one could do a stereo version by separating graphene coat into 2 sections.
I may be wrong BUT this is very high voltage. You shouldn't touch it. A battery isn't enough to supply that voltage for very long I wouldn't imagine. However, Martin Logan (or one of the electro speaker makers) decided to turn a car windscreen into a stereo panel just like you described! I've never come across one in real life. Check it out though
@@lowerthetone it is high voltage but extemely low amps so the wattage is fine - a flyback is just what i had you could use a cockcroft wheaton bridge which is what they use in air ionisers and the battery version of that lasts for days - really this is just a starting point for folks to think about and to think how could they do it better - i hope they do and post some good vids on it
Hi very interesting and immediately reminded me of the Leak speakers. The inearity of the LV to HV converter will be rather bad. About the build method could you suspend the two plates capacitor(this time with a foam separator. between)and then between the two outer plates of fixed high voltage and feed the audio to the inner capacitor so the whole lot will vibrate depending on respective rigidity.???
nice one mate - personally i think time spent creating a driver board would be time well spent - rather than cobbeling it together from bits in the lab - but as demo of what can be done from bits around - ilike it
@@lowerthetone you really don't want to use an audio amplifer - it's just what i had laying around - the best thing would be to design a control board specifically for electrostatic speakers
You are missing a pre-polarised stator to get this working properly. Plus a flyback transformer is a dismal choice for the A/C side of the system. Not the most well thought out on the physics side of how an electrostatic loudspeaker works. Most ESL's are using a very high resistance film. Your graphene film will be a low resistance setup. The low resistance can work but you will have a harder time keeping a proper set of stators charged.
obviously his design is different than conventional ESLs, but clearly there is potential in this direction, and I can see some advantages over the traditional design.
Electrostatic speakers are not famous for sound quality but there's a big potential for experimentation. Like trying multiple layers, multiple frequencies, maybe one layer but with different areas for different frequencies... Have fun :)
Since when are electrostatic speakers not famous for their sound quality? The oldest commercial ones, QUAD's ESL57, was elected in January 2000 as "best audio product of the 20th century" by Hi-Fi Newes and Record Review.
"Easy" - you just need a lab with $19k in equipment and electric engineering knowledge from 6 yrs of studies. Very easy. anyone can do it after 11 hrs of work!
@@ThinkingandTinkering hi Robert , the high voltage generator works with DC voltage and amplifier works with ac, doesn't that mean it shouldn't really work? I'm trying to make one and I needed your clarification
