Caring For Your Ribbon Microphone
The RIBBON microphone has a history rich in sound achievements. Look at virtually any old movie newsreel, photo journal, recording promo shot, show business and political picture, and you will most likely see the gigantic cages of chrome-plated windscreen-covered, electronic contrivances we know as ribbon, or velocity, or gradient, or ribbon velocity bigradient microphones.
They all had one thing in common: a "ribbon" of foil, an "eardrum" or "tympanic" membrane. Usually, they were 1/8 inch to 1/4 inch wide, 1 to 3 inches long, very thin (thousandths of an inch) formed in a corrugated or crease-folded pattern. The foils were suspended between two poles of a powerful magnetic assembly, one end grounded to the pole pieces or generating assembly, the other end insulated above the electric potential to enable current to be formed by the moving foil passing through the dense magnetic field. Essentially, this created a voice/sound-operated electric "motor". The fact that it is air coupled to an energy source makes it a primitive wind-to-electricity conversion device. Acoustically, this air pressure deflection of the ribbon is referred to as "sound pressure level", a term used in sound specification sheets.
These microphones are considered "indoor" or studio mics, generally due to the delicate nature of the fine ribbon of foil. Strong air blasts from wind, unwitting users blowing into the mic to test its level, bass or low frequency pa. speakers, will almost certainly drive this gossamer foil from its comfortable cradle, rendering it useless. The overdriven corrugations stretch the foil, allowing it to flap out of its gap, shorting it out on anything it touches, or worse, tearing it loose from its pole clamps, killing the sound totally. The following suggestions should help users understand correct and rewarding use of this wonderful creation - so kind to the human voice - the magical Ribbon microphone! Shure, E-V, Altec, RCA, B&O, Aiwa, Reslo, STC, etc. all made them.