Compressed-air gramophones: a loud, bad, wonderful idea

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19 Responses to “Compressed-air gramophones: a loud, bad, wonderful idea”

  1. BookGuy says:

    Somewhere out there, a youth with just enough skill to be dangerous is now hooking up an air compressor to the speakers in the trunk of his Honda Civic.

  2. edgore says:

    *This* gramophone goes to “11″

  3. dragonfrog says:

    The “Fortophon Starktonmaschine” – man, I love German.

  4. Mary Rose says:

    german has made a good high technology :)

  5. Gary61 says:

    Gives ‘crank it up’ a whole new meaning. 

  6. that whole “elderly” museum website is pretty awesome! 
    steam airplanes, gyrocars, analogue computers, armored houseboats, unicycles – one could almost call it PROTO STEAMPUNK :)
    http://www.aqpl43.dsl.pipex.com/MUSEUM/museum.htm

  7. robcat2075 says:

    I have an all-mechanical non-electronic 1920-something “Victrola” and the sound quality that comes from it is comparable to what is demonstrated in that video.  The quality of the record has much to do with what comes out.  Discs made after about 1927 with electronic mics and cutters sound dramatically better than the all-acoustic captures before that, even on a non-electronic Victrola.

    John Phillip Sousa famously hated the phonograph for its poor sound quality until, near the end of his life, he heard the first electronic recordings. 

    “Gentlemen,” he said, “THAT is a band!”

  8. i’ve been keeping an eye on the site for a while now – at some point i became obsessed with mono wheel vehicles, and this was one of the best i’d found;

    http://www.douglas-self.com/MUSEUM/TRANSPORT/motorwhl/motorwhl.htm 

  9. howaboutthisdangit says:

    It combines the audio fidelity of a gramophone with the subtlety and nuance of a calliope.

  10. Jorpho says:

    I vaguely recall that some orthodox synagogues use compressed air amplification systems on the Sabbath, but perhaps I am mistaken.

    • Ultan says:

      Here’s a 1997 Technology Review article,  “Kosher Sound”.

      • Kimmo says:

        Drzewiecki says the system works by “taking advantage of the mechanical gain obtained by the deflection of a high-energy jet of air.” As a person speaks into an input horn, the pressure waves generated by the voice hit a smooth jet of air released from a canister of compressed air and cause it to vibrate.

        The wavering jet stream is then split by a thin piece of laminated plastic into two channels, one carrying the upper range of the sound waves and the other carrying the lower range. The split sound waves are then routed through separate tubes so they will bang from opposite sides into another, faster-moving jet of compressed air. As waves from one channel push on the jet stream with positive pressure, waves from the other channel, which are completely out of phase, pull on it from the other side with negative pressure, increasing the amplification effect.

        The split jets of air, which travel with much more force than a voice, cause the smooth jet they come in contact with to vibrate at the same frequency but with higher amplitude. This phenomenon can add enough kinetic energy to the pressure wave to raise its volume tenfold. The amplified sound, imprinted with the original voice harmonic, travels along plastic piping and emerges from speaker horns at the ends of the tubes.

        The army engineers were able to demonstrate that the principle worked-but were not able to get the sound loud enough to be heard on flight decks where the cacophony frequently reached 120 decibels. Part of the problem was that they did not realize they could theoretically repeat the steps of the process indefinitely to achieve the desired volume.

        o_O

        At least 1 in 50 people are smarter than me, and that’s the first thing that occurred to me as I read the description. Pretty surprising that it wouldn’t be totally obvious to even someone of average intelligence…

        Although concerning the grain silo application, I’m not sure how a conventional microphone is capable of generating sparks; the current generated is tiny, and anyway, there isn’t any obvious means to do so in the absence of something like the brushes in an old-school electric motor.

        As for the rabbinical decree that using compressed air doesn’t constitute work in just the same way as using electricity does, that’s both dubious and (somewhat) convenient…

  11. Roy Blake says:

    In England vacuum tubes were called “valves”.  Interesting to see an amplifier using an actual mechanical valve.

  12. swishercutter says:

    I am reminded of these…

    http://webfaq.phoenixphorum.com/cyclone.htm

    http://youtu.be/qmqYk0KVTA0  Video of one running.

    For a minute in the 90′s they seemed to be the new tech…along with electrostatics I guess they never caught on big.

    • Kimmo says:

      Last two comments on the vid you linked:

      I had 2 of them . Big disappointment. Low output. Very limited frequency response. I swithed to two old Image Dynamics ID15s, running infinite baffle. Absolutely blew the cyclones away!! Not even close. And i really did like the concept of the cyclones.
      bottomfeeder73 1 year ago

      Hard to believe its been 14 years but back in 1996 we got a pair of them at our stereo shop and after trying them in several enclosures and configurations we ended up returning them to PG. They work for sub sonic and ultra low bass but you still had to have regular subs for 35 hz and up. It was a good idea but not a practical product and we could never get a customer to pay $650 a piece and we couldn’t even get dealer cost which was $350 if I remember right.
      foxacoustics 1 year ago

  13. idmat says:

    If you wonder how it’s actually done (and maybe want to build such a thing yourself) Bart Hopkin of Experimental Musical Instruments explains it all in this post on Acoustic Amplifiers: http://windworld.com/tools-techniques-ideas/acoustic-amplifiers/

  14. avraamov says:

    A steam driven version of this was demonstrated by Horace Short on Ditchling Beacon (just outside of Brighton), if memory serves. It was nick-named ‘The Howling Terror’ by the local press. A friend was looking to recreate the event, but was told it broke all modern noise emission and health and safety rules, so he gave up.

  15. pjcamp says:

    If only they’d called it the Fart-O-Phone, it would still be with us.

  16. cmholm says:

    For the primary consumers of the amp given by the museum page (restaurants and other public places) this seems (seemed) a must-have, after listening to the Youtube demo. I’m sure the measured distortion looks awful on an o-scope, but the Victrola in anything but the most quiet listening conditions was otherwise useless. 

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