well an idea i had before... but tried it kind of differently on a corrugated unsupported foil (no supports on the sides, no tention not even foam supports) might be interesting :)
OOh i must add although it added 1 dB, that aint completely true, i forgot i did lower inpendace by half.. so actually lost 2 dB or at least not gain any !
Met dank aan de voorstellen van RU-vid bij een van je video’s uitgekomen. Ik ben zelf al enkele jaren een grote magnepan fan en kijk ook al vele jaren RU-vid. Dan toch vreemd dat ik je nu pas heb gevonden. Beter laat dan nooit. Het ziet er naar uit dat ik de nodige uren nodig heb om de vele video’s te bekijken. Ik kijk er al naar uit! Hele leuke content wat ik zo snel heb gezien.
oooh wat leuk om te horen !! ja het is vreemd hoe het gaat ! als het niet viraal gaat gaat het heel langzaam maar gestaag , je hebt inderdaad nogal wat te kijken :) groot percentage is mhaah, maar mensen die zelf iets willen maken, eindigen toch vaak in , maar zoveel mogelijik kijken , soms is de video niet zo boeiend maar zeg ik soms nog wel dingetjes die wel nuttig zijn voor een eigen brouwsel :) die niet gerelateerd waren aan de video zelf haha :) ach ja hoop dat het helpt. vind het al leuk als mensen zelf wat proberen !
I think you need to do a 50-1000Hz sweep at medium SPL and see what the distortion says... As it is right now the weaker magnet field (and fewer coil runs) on the out of phase outer runs just lower flap, it doesn't remove it. I think you should try to add side support to the "ribbon" now that much of the movement is gone. Maybe even add two weaker rows of magnets on the outside of the inverted phase coil runs to increase magnetic flux there and help the inverted phase force. Electro-mechanical damping doesn't work in the way you described here, what you would really need to do what you described at first is an outer coil loop with an active zero reference (an amplifier that tries to keep the voltage of that loop at zero) - this makes the amplifier "respond" to any movement of the coil (since the movement induces a current/voltage) with a symmetrical "push-back" of the same voltage. This can resonate though, the feedback needs to be tuned to the mechanical system you use. I have done this with many industrial motor controllers on larger machines and robots - same principle. Rotation, since it's a motor - but linear motion is the same thing. So a weaker, inverse polarity outer coil might be a really, really good idea. Removes the tuning necessity, you just need to adjust the force ratio between main coil / outer coil
well i cant remove the flap completely (yet since this is my first try), but getting rid of most of it helps allot. keep in mind the foil needs to be 4 or 6 times bigger. and should get better and better , this is the worst case scenario small foil trying to pooop out 38 hz :) sine wave
yeah i have to play with the ratio!, now i made the mistake of having 2 traces in phase witch are uselles since they just add up to the original coil (since i was not planning on using a audio signal) , besides that i think ading more magnets witch is rather a waste of magnets, or try to get the balance right between audio coil and break coil... oooor give it a slight support and hope i can get rid of the breaklup this way next to the coil and where it is supported
Are you progressing to some form of monitor feedback where you use one of the coils to sense movement at the edge and the others to null it out. Anyway looks to be extremely cool area of development.
in this case it is the same audio signal been out of phase keeping the edge of such foil in line (as in not going overboard in excursion/flapping) a friend of mine is working on motional feedback on a planar though.. witch works for flat panels not sure yet for corrugated ones. yet
....and I also wonder if you've ever tried a bigger bipole cone bass section. They usually blend better with planars. I've heard a really good bipolar bass section developed for and used with the QUAD ESL-63, and that was incredible
looks like the inverted polarity on the second circuit is countering the standing waves created by the first circuit, pretty interesting The questing i have is regarding the undriven spaces between the first and second circuit, are they acting as a bending point helping the counter standing wave effect?
if you extend the Y axis to the roof, create a high pass where the lower freq is using the inverted circuit and the higher freq is natural, might be a way to extend the LF with an all in one driver
Panels always show weird resonances in decay traces. I've often though what would happen if you biased the whole panel with DC? Not sure if this thought might help you perhaps without corrugation.
well all the bias you add will make the efficiency less. i mean you are trying to mitigate what the coil wants to do. its only usefull i think where the foil is going beserk, not following the thing it should do :)
@@joppepeelen I have Eminent Technology planars. Magnets on both sides. If there is a continuous signal I guess it acts to damp the last impulse, as you say not going berserk. Sort of a stiff corrugated cloth damping material on the back side. The damping material controls the resonance below 100hz. Normal operating range bottoms out 150-200hz. Seems only really large panels get below 100hz. Enjoying watching your work and experimentation.
yeah tought about it by shorting it. but its not enough :) i tried that on a tweeter years ago, so im sure it wont work for this, maybe if i add faaaaaar more traces though, would be a charming solution if it did work
