Recording Studio: Ribbon Microphones

Recording Studio: What is a ribbon microphone?

A recording studio ribbon microphone is a type of dynamic mic in which a thin, corrugated strip of aluminum suspended between two poles of a strong magnet serves as the diaphragm and voice coil. The ribbon reacts to velocity of air particles (rather than the pressure, as with moving-coil dynamic mics) and as it moves within the magnetic flux field, it generates a small AC voltage proportional to this velocity. Clamps attached to either end of the ribbon also serve as contact terminals: Wires carry the signal to a step-up transformer, which then raises the output voltage and boosts the output impedance to a usable level for a preamp, typically around 150 to 300 ohms.
Because the ribbon element responds to sound waves arriving from the front or back, but is insensitive to sound coming from the sides, most ribbon mics have a natural bidirectional polar pattern, which makes them ideal for eliminating unwanted noise between two sources or for use in M/S and Blumlein stereo recording configurations. Classic ribbon designs do not contain internal electronics — just the ribbon, magnets, transformer and occasionally a passive highpass filter network.

Recording Studio: Expert advice on ribbon mics

Every good recording studio has a range of ribbon microphones.  Here are some quotes from some of the worlds best recording studio producers on when they use ribbon mics in the recording studio:
Roger Lindsay: “Lead and pedal steel guitars.”
Julian King: “I frequently use them on guitar amps, drum room mics and acoustic instruments like guitar and dobro.”
Eric Schilling: “I use ribbon mics in lots of applications, drums, horn sections, guitar amps, pianos. I often will choose a ribbon mic when I want a smoother top end and a more rounded bottom. If I am recording and find the sound too bright, I will often switch to a ribbon. I have also found that using a ribbon on an electric guitar will give me a very natural sound.”
Mike Sponarski: “Besides being in front of a high SPL guitar amp, I’ve experimented with ribbons in a kick drum and on the bass amp. There hasn’t been any clipping, distortion or damage. These ribbons have been able to handle anything I’ve thrown at them so far. I’m very happy with them.”