Ribbon Microphone Care Tips
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 wonderfiil 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.
Never blow into this, or any type of microphone, to test it. Talk sing, play your harmonica or employ whatever the ultimate intent the user has designated. Ribbons hate wind, speaker ports, and things like bass drum close miking.
Don't Lay It Down
Never lay a ribbon mic down on any surface. The powerful magnet literally "vacuums" up microfine particles of iron, known as "tramp metal", invisible to our eyes, but lying about as the most common element on earth. Theatres and backstages, roadie and equipment storage areas are rich in minute tramp iron. Beware! Iron bits, so tiny as to pass through wind screen or foam protectors, lodge in the voice coil gaps stopping ribbon coil movement, robbing performance, first as bass frequency loss, level drop and distortion.
Protect From Air Blast
If you have to use outdoors, cover the mic with an acoustic semi- closed cell foam windscreen. If none is available, use Artfoam, a hobby shop product, 1/8 inch thick, usually grey or beige in colour and in sheets large enough to make a nice substitute protector.
Take care when using "Phantom Power" mic mixer inputs. These 48-volt power supplies are designed to provide Condenser Mics with the necessary voltage they require in order to work. Condenser mics, whether self-powered with batteries, or this line-provided voltage, use the electric current on the mic cable connected to the mic in use. If the current should get to the ribbon element, it will be destroyed instantly.
Avoid Heat, Humidity, Rough Handling
In spite of the delicate nature of the Ribbon microphone, it has survived some terrible environmental usage. Shure actually advertised that they "pounded nails" with one of the 330 or 315 series. Use a hammer! Heat and humidity are not good for any electronic devices, but a mic like this does not generate its own heat and tolerates the environment very well. Common sense should prevail for use.