Researchers develop a paper-thin loudspeaker:
This thin-film loudspeaker produces sound with minimal distortion while using a fraction of the energy required by a traditional loudspeaker. The hand-sized loudspeaker the team demonstrated, which weighs about as much as a dime, can generate high-quality sound no matter what surface the film is bonded to.
To achieve these properties, the researchers pioneered a deceptively simple fabrication technique, which requires only three basic steps and can be scaled up to produce ultrathin loudspeakers large enough to cover the inside of an automobile or to wallpaper a room.
Used this way, the thin-film loudspeaker could provide active noise cancellation in clamorous environments, such as an airplane cockpit, by generating sound of the same amplitude but opposite phase; the two sounds cancel each other out. The flexible device could also be used for immersive entertainment, perhaps by providing three-dimensional audio in a theater or theme park ride. And because it is lightweight and requires such a small amount of power to operate, the device is well-suited for applications on smart devices where battery life is limited.
[...] A typical loudspeaker found in headphones or an audio system uses electric current inputs that pass through a coil of wire that generates a magnetic field, which moves a speaker membrane, that moves the air above it, that makes the sound we hear. By contrast, the new loudspeaker simplifies the speaker design by using a thin film of a shaped piezoelectric material that moves when voltage is applied over it, which moves the air above it and generates sound.
Most thin-film loudspeakers are designed to be freestanding because the film must bend freely to produce sound. Mounting these loudspeakers onto a surface would impede the vibration and hamper their ability to generate sound.
To overcome this problem, the MIT team rethought the design of a thin-film loudspeaker. Rather than having the entire material vibrate, their design relies on tiny domes on a thin layer of piezoelectric material which each vibrate individually. These domes, each only a few hair-widths across, are surrounded by spacer layers on the top and bottom of the film that protect them from the mounting surface while still enabling them to vibrate freely. The same spacer layers protect the domes from abrasion and impact during day-to-day handling, enhancing the loudspeaker's durability.
Journal Reference:
An Ultra-Thin Flexible Loudspeaker Based on a Piezoelectric Micro-Dome Array, (DOI: 10.1109/TIE.2022.3150082)
(Score: 2) by maxwell demon on Thursday April 28 2022, @10:23AM (1 child)
Now if they also can make that material transparent, maybe they can put the smartphone's speaker back to where it actually belongs, despite that place now being taken up by the display.
It would be nice to no longer have to see people needing to hold their phone perpendicular to their ears in order to hear something. That just looks ridiculous.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @02:41PM
Audio books For those that can't/won't read? Audio-graphic briefing material for TFG?
(Score: 1, Interesting) by Anonymous Coward on Thursday April 28 2022, @11:13AM
This sounds really good and I like the idea.
The problem of generating noise cancellation in a volume (as opposed to inside headphones) is the reflections on surfaces and the inability to source the anti-phase signals exactly where the noise originates. If the noise cancellation does not originate very close to the origins of the noise, it will not propagate the same way as the noise and some volumes of the space will experience noise cancellation whereas others amplification. With a huge array of sensors (i.e. microphones) spread over the surfaces that emanate or transmit the noise coupled to extremely fast anti-phase signal generation and the ability to inject this noise cancellation signal to exactly the right part of the surface without interfering with the noise detection, it may be possible if not feasible.
As with all new technology, let's see what the future brings before applauding. Still, I do like the idea!
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @11:14AM
Did I understand this correctly? Instead of having one large speaker their speaker is made up out of many small speakers instead?
(Score: 5, Insightful) by Snospar on Thursday April 28 2022, @02:13PM (1 child)
This is perfect for people who've grown up listening to the sound out of mobile phone speakers. All high range with absolutely no bass. They get 86 dB at 10kHz but lower than that they have much lower volume and distortion sets in. Given that Middle C is 264 Hz this is not going to produce good quality audio until they address the frequency range.
But speaker wallpaper! WTF?
(Score: 2, Interesting) by Anonymous Coward on Thursday April 28 2022, @04:47PM
Exactly, there's 20 dB of slope going one decade from 1 to 10 kHz. That's total crap for a speaker.
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @02:21PM
if you have a old (disposable) vinyl record you can take a piece of paper thin ...errr... paper, roll it into a cone shape and pierce the narrow end with needle, run the plater and drop the needle in a grove and have your analogue paper thin?
also, wikipedia:soundbug?
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @02:25PM (9 children)
Highs can be done by little flat speakers. Bass requires a speaker to move much farther back and forth than these flat speakers can do. Bass (and decent mids) always requires a cone speaker commanded by a coil producing a magnetic field. Physics, what is it?
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @03:16PM (3 children)
"move back and forth". no. sound is a pressure/density wave. you don't need movement to create it, you just need pressure/density fluctuations.
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @04:51PM (2 children)
You're completely wrong. Yes, sound is propagating prssure waves, but you need some kind of mechanical vibration or movement (back and forth) to create them.
(Score: 2) by ChrisMaple on Thursday April 28 2022, @10:48PM
Yes, generally you need a moving solid object to generate controlled sound. However, there are throttled flow loudspeakers and speakers that make sound by manipulating a plasma.
(Score: 0) by Anonymous Coward on Friday April 29 2022, @02:03AM
Don't sweat it.
Your Parent is likely trained in MBA and Marketing,
Not Physics or Engineering.
And, try as yow will, you will never convince them otherwise.
They have already been trained that they are your superior. They even have a piece of paper that says so.
If you find yourself working for one, I suggest you start looking for another job.
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @03:24PM
Of course there's no point getting the high quality paper speaker unless you also invest in the handmade gold audio cable.
(Score: -1, Flamebait) by Anonymous Coward on Thursday April 28 2022, @05:03PM
The autotuned garbage millennials listen to can be handled perfectly by little flat speakers, so stop raining on their parade.
(Score: 1, Informative) by Anonymous Coward on Thursday April 28 2022, @07:57PM (1 child)
...although these speakers were not small, but large:
https://en.m.wikipedia.org/wiki/Electrostatic_loudspeaker [wikipedia.org]
Quote: Arthur Janszen was granted U.S. Patent 2,631,196 in 1953 for an electrostatic loudspeaker. He had worked in the Navy to develop a low-distortion, high-frequency source for targeting torpedoes. After the war, he developed manufacturing technique for electrostatic speakers, to be used with conventional cone woofers, known as electrostatic hybrids.
Another quote: There is also the difficult physical challenge of reproducing low frequencies with a vibrating taut film with little excursion amplitude; however, as most diaphragms have a very large surface area compared to cone drivers, only small amplitude excursions are required to put relatively large amounts of energy out. While bass is lacking quantitatively (due to lower excursion than cone drivers) it can be of better quality ('tighter' and without 'booming') than that of electrodynamic (cone) systems.[citation needed]
---
Note that the Wikipedia speakers are LARGE; smaller speakers as mentioned in the article can't overcome weak bass this way. Arguably, since the Wikipedia speakers are always sold with a cone speaker, they don't realistically overcome weak bass either without help.
(Score: 3, Interesting) by number11 on Thursday April 28 2022, @11:37PM
Long ago (early 1970s), I had a pair of full-range Acoustech electrostatic speakers, loaned to me because they didn't fit into their owner's apartment. They were made up of small (5"x9"?) units, and each speaker comprised a panel about 2x4 ft, mounted on a heavy base that contained its amplifier (about the size of a 3U rack-mount), and with an added central dynamic bass speaker (as others have said, electrostatic speakers have poor bass performance). The sound was wonderful, we played around some recording sounds on a prosumer reel-to-reel tape deck, and doing A-B comparisons (live vs. recorded). You could not tell real from recorded if you kept your eyes closed. The disadvantage was the amount of floor space they took up, made worse because their placement was critical. They were extremely directional, your listening location had to be at the intersection of imaginary lines perpendicular to both panels (at least, in my apartment).
(Score: 0) by Anonymous Coward on Friday April 29 2022, @04:00AM
> Bass (and decent mids) always requires a cone speaker commanded by a coil producing a magnetic field.
Guess you've never heard Magneplanar speakers, have you? https://magnepan.com/ [magnepan.com] They may not satisfy everyone but my friend's pair sounded excellent to me with a variety of different source material. Not cheap, but you get what you pay for.
Roughly speaking these are the magnetic equivalent of electrostatic panel speakers. From https://magnepan.com/pages/faqs [magnepan.com]
> If you make it big enough, a full-range dipole speaker can equal the bass performance of a dynamic speaker. We could have gone the route of other companies and made a hybrid speaker that uses a dynamic woofer for the bass. We made some prototypes, but they didn't sound like a full-range ribbon speaker. Again, it was a choice. Should we stick with a purist strategy? Race car engines are not a compromise. But, there is a "price" to be paid for the performance — size.
(Score: 0) by Anonymous Coward on Thursday April 28 2022, @11:21PM
I don't know enough about speakers to comment on the fidelity of this, let alone other things. One thing which does stand out, though, is I remember hearing that speakers and microphones are effectively identical to each other. This does make me wonder if there are new applications of this same technology to make new (possibly clandestine) microphones.