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Music Science

New Headphones Generate Sound With Carbon Nanotubes 102

MTorrice writes "A new type of headphone heats up carbon nanotubes to crank out tunes. The tiny speaker doesn't rely on moving parts and instead produces sound through the thermoacoustic effect. When an alternating current passes through the nanotubes, the material heats and cools the air around it; as the air warms, it expands, and as it cools, it contracts. This expansion and contraction creates sound waves. The new nanotube speaker could be manufactured at low cost in the same facilities used to make computer chips, the researchers say." And it exists in the real world: "The Tsinghua researchers integrated these thermoacoustic chips into a pair of earbud headphones and connected them to a computer to play music from videos and sound files. They’ve used the headphones to play music for about a year without significant signs of wear, Yang says. According to him, this is the first thermoacoustic device to be integrated with commercial electronics and used to play music."
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New Headphones Generate Sound With Carbon Nanotubes

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  • by Anonymous Coward

    I heard you like tubes, so I put acoustic nano tubes in your series of tubes, so you can hear the tubes while you tube!

  • Yes, but... (Score:5, Insightful)

    by mellon ( 7048 ) on Monday September 30, 2013 @06:48PM (#44996489) Homepage

    ..what do they sound like?

    • by Anonymous Coward on Monday September 30, 2013 @06:52PM (#44996521)

      They're thermoacoustic, so I'd guess they have a nice warm sound.

    • Well, assuming they get the R&D effort to refine them, presumably whatever you like, at the appropriate price point.
      A fixable issue methinks, if the basic technology works, as it seems to.

      Could be nice way of sidestepping the Chinese and their "rare earth" near-monopoly.

      (Although my old electrostatic speakers do that too, and sound fantastic. Not sure the voltages involved would scale to ear buds powered by mobile devices, tho')

      • Re:Yes, but... (Score:4, Informative)

        by PaulBu ( 473180 ) on Monday September 30, 2013 @07:02PM (#44996601) Homepage

        Could be nice way of sidestepping the Chinese and their "rare earth" near-monopoly.

        Judging from the author's names and affiliation, I quite doubt that it was their main motivation... :)

        Yang Wei *, Xiaoyang Lin , Kaili Jiang *, Peng Liu , Qunqing Li , and Shoushan Fan
        Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, P. R. China

        But, it's still VERY COOL!

        Paul B.

      • by mellon ( 7048 )

        Hm, sounds like a cheap route to shock therapy!

      • Re:Yes, but... (Score:5, Interesting)

        by jd ( 1658 ) <{moc.oohay} {ta} {kapimi}> on Monday September 30, 2013 @07:21PM (#44996729) Homepage Journal

        It depends. Sound quality doesn't scale, generally, which is why standard speaker systems have vast arrays of speakers that operate over very narrow ranges. The sound quality using cones and magnets has gone as far as it can, short of moving to superconducting electromagnets.

        There were some speakers demo'd on Tomorrow's World, way back when, which consisted of an electrode in a spherical wire mesh. The spark, pulsed at the right frequency, could generate sound. It was extremely high quality, far far higher than the Tesla Coil speakers you see on YouTube. But nothing ever came of the idea. Still not entirely sure why, but I suspect large amounts of ozone and the power you'd need to cross the gap they were using would make such a device uneconomic.

        The nanotube idea is interesting, but I have a real concern that technology these days isn't about quality but quantity. Notice how the summary emphasizes the production of the system, but also observe how DVD lifespans are pathetic, hard drives have much shorter MTBF than earlier generations, MP3s largely replaced lossless codecs, digital cameras have a fraction of the effective pixel count of film, etc. Nobody wants high-end. They want crap that's tolerable and affordable. (Which also explains why Windows is a "success" and Linux has never made it to the desktop -- yet is the only serious OS in the few luxury/demanding markets left.)

        It could be that nanotubes will prove to be capable of high-end sound, REAL hi-fi sound, but let's face facts. Even if it was, even given that the technology exists for 11.1 sound with an upper operating limit of 384 KHz at 24 bits, when was the last time you saw a CD with music recorded at that level? People want more tracks per piece of physical medium and would probably settle for 16 KHz at 16 bits resolution if it gave them a few more bonus tracks. There are audiophiles out there. I know. I'm one of them. Although, sometimes I think I'm the only one left. That depresses me, but you have to wonder. Purported audiophiles who can't tell what gives good sound and what doesn't clearly aren't audiophiles at all, they're blingophiles.

        • Re:Yes, but... (Score:4, Interesting)

          by HornWumpus ( 783565 ) on Monday September 30, 2013 @07:58PM (#44997001)

          You might be thinking of plasma tweeters. Back in the late 70s/early 80s. 10K1980$ a pair. Just tweets.

          They had a gas flame that was made to generate sound with an electric field. Note: Typical electrostatics already have membranes that weigh less then the air they're moving.

          Your dog _might_ be able to distinguish between plasma and normal electrostatics. Not that electrostatics are exactly cheap or small.

          • You might be thinking of plasma tweeters. Back in the late 70s/early 80s. 10K1980$ a pair. Just tweets.

            They had a gas flame that was made to generate sound with an electric field.


            You may be thinking of Hill Type 1 Plasmatronics that were $10k a pair back in the late 70s. The tweeters were both amazing and possibly hazardous to your health due to the ozone emitted into the room. The sound from the other drivers in the speakers couldn't keep up with the tweeters, though, especially the woofers. And unfortunately the tube amps built in to drive them were horribly unreliable, and each speaker had a helium tank you would have to get filled once in a while. Not to mention cosmetics that m

            • I specifically remember they were only tweets and they required a natural gas line to each speaker. Don't remember the brand or model.

              With the plasma generated by flame they shouldn't have made much ozone.

        • Also, to add to the other person already talking about electrostats, magnetic speaker development isn't dead by far. You don't need rare earth magnets for "living room size" speakers and you also don't need cones. In the past, experiments have been done with using flat carbon fiber honey combed round "plates" that were attached with a very light and solid construction to the voice coil of a speaker. Those took out a lot of the distortion and deformation you typically get with a classical cone speaker. Devel

        • (Which also explains why Windows is a "success" and Linux has never made it to the desktop -- yet is the only serious OS in the few luxury/demanding markets left.)

          But Linux (on the desktop) is a fucking piece of shit. Windows 2000 is far better than the latest Mint, Ubuntu or Fedora crap, let alone Windows 7.

        • You're thinking of the Plasmatronics product line, which, I believe, debuted in the late 1970s. Heard a pair once in NYC way back when & the high-end was pretty remarkable. Suitable mainly for tweeters & supertweeters. They don't use an extraordinary amount of electricity and produce only a tiny amount of ozone. But they require a supply of halogen gas, which I recall makes an annoying hissing noise.
      • by icebike ( 68054 )

        Could be nice way of sidestepping the Chinese and their "rare earth" near-monopoly.

        Rare earths used in Earbuds? Who knew?!

        They also said they used them for a year with no sign of wear.
        Just like every other pair of earbuds.

        • It is possible to blow out a pair of earbuds by cranking the volume up too high, but usually they will sound awful because of increasing distortion well before the danger point. Most earbud failures are mechanical problems - breaks in the cable or connections coming loose. Presumably this new technology will be neither more nor less prone to those problems than existing earbuds are.
    • by ackthpt ( 218170 )

      What do they look like?

      Probably like Princess Vespa's.

    • by mcgrew ( 92797 ) *

      ..what do they sound like?

      Like earbuds. Not exactly high fidelity, but what earbud is? I'm wondering how well they handle high frequencies, though, which magnetic buds do easily. Thermoacoustic seems like it would be quite a bit slower than electromechanical.

      I wonder what manufacturing costs are compared to magnetic earbuds?

      Interesting concept, though, whether or not it's really practical.

      • There are plenty of high fidelity earbuds available. Etymotic pioneered the category; now you can also buy products from Shure, Ultimate Ears, Bowers & Wilkins, Sennheiser, Klipsch, Westone, JH Audio and more. Even Grado makes some now. Bring money; most of these will cost you over $100, in some cases well over - the most expensive JH Audio and Shure models sell for $1000 or so. To be clear, these are IN-ear products; if you're looking at the kind that just kind of sit in the ear rather than having a fi
    • Re:Yes, but... (Score:5, Interesting)

      by Charliemopps ( 1157495 ) on Monday September 30, 2013 @08:55PM (#44997467)

      I'm willing to bet they have very similar performance to Electrostatic speakers. Very low distortion, acting like a dipole radiator so you have to spend a lot of time positioning them to get them to sound right, very good dampening due to low driver weight. I'd suspect these things have near perfect dampening since all they're moving is a magnetic field and air.

      There are a lot of downsides though, and I think they'd all apply here as well. Most notably, terrible bass response. And the number 1 problem in sound reproduction is and has always been bass. This is basically yet another new and inovative way to reproduce high frequencies. We have hundreds... yay... []

      • by sFurbo ( 1361249 )

        acting like a dipole radiator so you have to spend a lot of time positioning them to get them to sound right,

        Wouldn't they be monopole radiators nearly by definition? If they work by making the air expand and contract, I fail to see what part would be the other pole. And wouldn't a monopole be better in the low frequencies than a dipole?

        • I don't think so. Monopole speakers are kind of... fake. If you're increasing pressure in one direction it decreases in the other. The difference in a "monopole" is that the pressure is decreased inside an enclosure. The majority of speakers are monopole. I suspect they could mount these in such a way that they'd be mono-poles, but they still wouldn't have very good bass response unless that's a hell of a magnetic field.

          • by sFurbo ( 1361249 )
            But these are not like normal speakers. They actually have an expanding and contracting part (the air that warms and cools), in contrast to normal speakers. When the air expands, there is nowhere where the pressure decreases, only places where the pressure increases, isn't there?

            Now, judging from the rest of the thread, they have other problems, particularly dissipation of thermal energy (who would have thought that a device that works by heating air could have such a problem), so it doesn't seem like th
    • The sizzle you hear is the burning hair in your ear.

    • Who cares, they've found a way to make even more expensive headphones!

    • by sh00z ( 206503 )

      ..what do they sound like?

      Yeah. How real is it? Not a single mention of frequency response or S/N ratio in TFA. It could sound like an Edison wax cylinder for all we know.

  • by mythosaz ( 572040 ) on Monday September 30, 2013 @06:54PM (#44996543)

    Ultin I can buy replacement headphones using this technology on DealExtreme for $2 shipped, it's a novelty at best.

  • How loud could it get?
  • The only benefit to this technology that the article mentions is that it "can greatly improve the device robustness and durability" and says nothing of the sound quality. It made me assume this would be used for MP3 player earbuds rather than headphones but then the article mentions "the speakers consume relatively high levels of power, because of their low efficiency of converting electrical energy into sound." Sounds like this has no practical commercial application at the moment.
  • by Anonymous Coward

    Electrons move... bitch —Aaron Paul

  • If you're ever given the opportunity to wish for a single superpower: don't think, just blurt out "CARBON NANOTUBES".
  • by CCarrot ( 1562079 ) on Monday September 30, 2013 @07:07PM (#44996641)


    Unfortunately, the devices struggled to dissipate the heat created while generating sounds,

    Careful not to crank the music on your new nanopodz(tm) too loud, or you'll literally fry your eardrums...

    OTOH, talk about a hot beat :o)

    • by geekoid ( 135745 )

      So everyone will sound like BIlly West?

    • Careful not to crank the music on your new nanopodz(tm) too loud, or you'll literally fry your eardrums...

      No, you "literally" won't fry your eardrums, because frying by definition requires oil or fat and if it's not already there in significant quantities, it's not frying :-P

  • by BoRegardless ( 721219 ) on Monday September 30, 2013 @07:10PM (#44996657)

    The researchers noted that "unfortunately" the nanotube speakers use much higher amounts of power to drive them.

  • No need for rare earths now? Maybe we dont have to mine for that shyte anymore considering the refining process.

  • by Jah-Wren Ryel ( 80510 ) on Monday September 30, 2013 @07:15PM (#44996697)

    Forget little dinky nano-tubes in your ears, a real man would put plasma arcs in their headphones. Like this: []

  • by Puls4r ( 724907 ) on Monday September 30, 2013 @07:20PM (#44996727)
    I wasn't aware that our current headphones had any problems that would be addressed with nanotubes. We have small phones that fit in the ear, big phones that look stupid on peopel, and everything in between. In all my years of using earbuds, it's always the cord that fails. Not the buds themselves. Now if they can fix THAT problem, that'd be worth something.
    • by wjcofkc ( 964165 )
      For people who spend a tremendous amount of time listening to music on the their phone, the power those little speakers draw starts to add up. If these use any less power without sacrificing quality, it could be a big deal. Of course the article does not actually mention anything like that so if it's not the case, then yeah your right - it's kinda pointless. They talk about increased durability, but I have eight year old earbuds that sound as good as new and most people lose a set more than once a year anyw
    • Dynamic drivers, as are normally used in headphones and speakers, still have problems in that regard. We can build amps, DACs, and so on that are essentially better than our hearing. Their frequency response, noise level, and THD are so low that they are completely inaudible, you can swap them out in a blind test and nobody can tell.

      Then you hit the playback device and that all goes to hell.

      You are hard pressed to find something that is both economical and has a flat FR and low distortion. Ideally you want

    • If you pony up for the shiny earbuds (aka "IEMs") the cord is usually replaceable. For those in the $10-$20 earbud crowd, sorry but you are out of luck.
  • I can think of an application. Imagine a room where every wall was covered in this stuff. With a sufficiently complex controller, it wouldn't be 5.1 or 7.1 surround sound anymore, it would be infinity point one surround sound. Of course this would require a whole new means of encoding audio that stores each sound element separately with its own location vector. A problem for movies, but entirely feasible for games.
  • I guess it isn't known whether carbon nanotubes are toxic: "These results suggest that carbon nanotubes are potentially toxic to humans and that strict industrial hygiene measures should to be taken to limit exposure during their manipulation." (
  • Any headphones i've ever had have suffered cable problems long before the buds themselves have started to show any signs of wearing out.
    • For me it's the padding on the ear pieces that goes out first. The actual sound generating components never fail. Ultimately the new technique will have the same problems as current techniques: they'll be uncomfortable and either make your ears sweat or feel like there's something stuck in your ears. I'll gladly settle for poor sound quality if only it were comfortable.

  • so why are these better?
  • I really am uncertain on the disposal methods of nanotube based devices / materials? I know that if they get into the water, they can screw things up. Has there been a advancement in disposal I'm unaware of? And if not, would this company be responsible for the damage they could cause. At least, in theory?
  • Tsinghua University (Score:4, Informative)

    by Guppy ( 12314 ) on Monday September 30, 2013 @08:31PM (#44997299)

    The Tsinghua researchers...

    My first thought upon reading the summary was, "Which Tsinghua University"? In this case it's the one in Mainland China, but there's a fascinating backstory behind my initial confusion regarding the history of Tsinghua University [].

    Following the defeat of the Boxer Rebellion [] (1899 - 1901), the China was made to pay an enormous sum in reparations to the great powers -- Russia, Germany, France, Britain, Japan, and the US. While the American share of the reparations was relatively minor (about 7% of the total) it still represented an excessive amount. American Secretary of State John Hay -- serving in the administration of Teddy Roosevelt -- arranged for about a third of the funds to be used for to set up scholarships, as well as a new school in Beijing which served to prepare students for overseas study in the US. It was this institution that eventually became Tsinghua University, one of the most prestigious learning institutions in China.

    There's more to the history however. Following the Chinese Civil War, the defeated Nationalists retreated to Taiwan. A large portion of the Tsinghua staff fled with them and founded a new Tsinghua University in Taiwan (or perhaps they merely re-located the original to Taiwan, depending on your point of view). This other Tsinghua went on to become one of the top Universities in Taiwan as well.

    • by aiht ( 1017790 )
      Thanks, Guppy. That is a fascinating story. The world's quite an interesting place, if you only take the time to look.
  • Most people listen to MP3 files through crappy buds. I listen to mp3's myself in the car (where quality doesn't really matter), but back at home, it's either vinyl, tape, or FLAC (or 320 MP3 at least). While taking walks, I listen to tapes using a 25-year old Walkman with Porta-Pro headphones (, themselves about 20 years old.

    Besides, most of modern *music/noise* is compressed to hell to sound louder, like we d

    • Same driver as the PortaPro, but they don't hurt my ears like the PortaPros do after a while. (This may just be a fit thing, I have a large head.)

      The downside is, they look kind of odd...

  • Please wake me up when someone discovers a thing that carbon nanotubes can't do.
  • Personally I would rather keep cheap Chinese knockoff headphones full of nanotubes away from my brain. How do you know the pounding of a bass beat is not actually injecting nanotubes through the fabric and eventually migrating them with vibration into your brain? Even if there is "no chance of danger" (as if anyone has actually packaged nanotubes in an energetic, electromagnetically pumped environment near the human body) I would just not feel like it is something safe to have around. Imagine someone came u

    • If nano isn't critical and in a highly safety engineered package far from me (or at least something biologically created that I have a chance of breaking down), I don't want it.

      Better not go anywhere near any roads, then. Or anywhere at all, probably.

      I know, we'll just call them picotubes. Problem solved!

  • crank the volume to the max to get heated earphones? ;)

  • The Tsinghua researchers integrated these thermoacoustic chips into a pair of earbud headphones and connected them to a computer to play music from videos and sound files. They've used the headphones to play music for about a year without significant signs of wear

    Unless it's a really unique computer, I doubt it generates copious amounts of ear wax nor occasionally goes out in rain showers sans umbrella.

    More to the point: I've never had earphone speakers fail; it's always the wires that break. Solve *that*

  • For some reason all the music sounds like this: []

  • Doesn't this have the same amount of moving parts as any speaker? The only movement is the vibrations that are created as sound. Am I missing something?

  • This started out as pure satire, but now I'm beginning to wonder if it could be done. Consider: it's relatively easy to produce extremely accurate analog electronic waveforms. The disasters strike while trying to convert (nanotubes, rare-earth magnets, cones, electrostatics, or whatever) into a clean pressure wave in air. And all that just to drive a bunch of scilia in the inner ear, which are probably beat to shit from a lifetime of rock concerts, motorcycles, and angry spouses. So let's get going on a

"Everyone's head is a cheap movie show." -- Jeff G. Bone