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From: shop@uwmcsd1.UUCP (Electronics Shop)
Newsgroups: net.audio
Subject: Re: ribbon vs. electro statics
Message-ID: <351@uwmcsd1.UUCP>
Date: Tue, 30-Jul-85 09:00:10 EDT
Article-I.D.: uwmcsd1.351
Posted: Tue Jul 30 09:00:10 1985
Date-Received: Thu, 1-Aug-85 00:24:51 EDT
References: <42400009@hpfclo.UUCP>
Organization: U of Wi-Milwaukee, Computer Services Div
Lines: 37

> A salesperson at a local audio store recently pointed out to me that
> there is a difference between electro-static and ribbon speakers. Could
> someone explain to me the difference, and how electro-static speakers
> work? Thanks in advance.
> 
> Bob Schneider
> {ihnp4|hplabs}!hpfcla!hpfclo!rjs

If I recall correctly, ribbons work by electromagnetic induction through the
aluminum ribbon voice coil. Electrostatics are full range speakers ( I've
seen ribbon midrange but not ribbon woofers :-) .

The basic 'static is a thin piece of film-like material, such as mylar, that
is driven by the audio signal. This film is suspended between two perforated
metal plates that are charged to a couple of kilovolts. The audio signal is 
also stepped up through a transformer. One plate is charged positive and the
other negative, and the mylar moves toward one and is repelled by the other
due to electrostatic attraction/repulsion.

The major difference is that the ribbon is 'just' a tweeter (or mid)
but a 'static is a full range, although many complain of lack of lower
bass. A subwoofer helps, but is sometimes too slow, and there might be 
an audible delay. Some disadvantages of 'staics are the low impedance,
sometimes as low as two ohms -- need an arc welder to drive them sometimes.
Another is the high cost -- my Koss ESP-10 headphones retailed for $350, 
and Quads can cost up to $2K or more. If you have a limited budget,
ribbons can be bought to upgrade your existing speakers, or if you
have bucks and an amp that can power New York City, electrostatics 
can be the best investment you ever made.


Thomas Krueger
-- 
Engineering Electronics Shop
U of W - Milwaukee
ihnp4!uwmcsd1!shop 
uwmcsd1!shop@wisc-rsch.arpa