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Conference hips::uk_audioo

Title:You get surface noise in real life too
Notice:Let's be conformist
Moderator:GOVT02::BARKER
Created:Thu Jul 28 1988
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:550
Total number of notes:3847

77.0. "Tie a Yellow Ribbon ??" by 42211::MATT (Matt le Ratt) Tue Apr 18 1989 12:22

    A friend of mine has just acquired some "Ribbon" speakers.
    The speaker dimensions are approx 48"*18"*1.5". They produce quite
    a nice sound, but HOW do they work ????
    
    Any info appreciated.
    
    Matt.
    
    P.S. We couldnt get the covers off to have a look and I can't remember
    the make.
T.RTitleUserPersonal
Name		DateLines
77.1I'll stay on the bus....BAHTAT::SALLITTDave - @RKG & ICI, 0642432193Tue Apr 18 1989 13:3013
    They're probably electrostatics, � la Quad. The ribbon is charged
    electrostatically with respect to a thingy (the name of which escapes
    me), and this field is modulated by the amplifier's output. This
    causes the ribbon to vibrate, producing sound. Your size estimates
    indicate they're probably one of the American designs - Apogee or
    Magnepan perhaps?
    
    Almost certainly power-hungry and notoriously demanding on the quality
    of signal that drives them.
    
    Sorry I can't be more technical/informative.

    Dave
77.2from accross the pond...PNO::SANDERSBSomewhere between Oz and WonderlandTue Apr 18 1989 16:3518
        If they are ribbon speakers, they work by suspending a membrane,
        usually aluminum (for low frequency panels) or an aluminum ribbon
        on polyamide film in a magnetic field and applying current to the
        aluminum which causes the aluminum to be attracted to or repelled
        away from the magnets.
        
        If they are electrostatics, then that consist of a stator which
        is charged with a DC voltage, usually around 4,000 V.  The signal
        is applied to a polyamide film which is impregnated with carbon
        and stretched in front of the stator.  The AC voltage (signal)
        causes the film to be attracted to or repelled away from the the
        stator.
        
        If the speakers need ac power (they have a wall plug) then they
        are electrostatics, if not then they are ribbons.
        
        Bob