A ribbon microphone picks up sound wave vibrations on a thin corrugated metal ribbon suspended between poles of a permanent magnet. Minute vibrations interfere with the magnetic field of the gap. The resulting voltage differential mimics the acoustic waveform thoroughly and transmits it through the ribbon's fixed ends to the electronic output. These reliable devices serve in professional broadcasting contexts, often as the familiar lozenge-shaped microphones from the Golden Age of radio. Contemporary digital recording has created new demand for their warmer analog qualities; modern designs have improved their construction and helped overcome their reputation for frailty.
Known for its sensitivity, the ribbon microphone often sits in a shockmount to protect against the sounds of minute movements. Velocity-actuated type ribbons detect sound waves on both sides, while pressure-actuated type ribbons only detect from a single side. Ribbon microphones belong to the dynamic family of microphones, as compared to the moving-coil variety. Typical thin ribbons responds in a free and natural way to sound vibrations, which results in a realistic reproduction of even complex analog waveforms.
The sound reproduction capability of a ribbon microphone is typically smooth and detailed, with a robust range through low, mid, and high ranges. This permits versatile equalization (EQ) and experimentation, and avoids the distortions or tinny responses of other types of microphones. The ribbon microphone has a reputation for detailed responsiveness and reluctance to peak. It is also said to avoid the unnatural brightness of some condensers, as well as the inconsistencies and limited ranges of less eardrum-like plates or coils.
Sometimes the thin diaphragm of the ribbon microphone requires phantom power in order to enhance the signal for more optimal recording. These microphones are also said to be more fragile with loud noises. With a long tradition in broadcasting, antique models are sought out, while companies continue to produce innovative new varieties. Enthusiasts experiment with these microphones and their figure-eight pickup pattern by moving vocalists, instruments, or amplifiers around the room, and engineering the robust signal to suit. While relatively obscure compared with other microphone types, ribbon microphones enjoy a loyal devotion from many audio professionals.
Able to pick up sound more like the human ear, the ribbon microphone duplicates relatively warm, natural sound compared with other designs. Ribbons may capture intrinsic qualities of voices and instruments, or complex amplified effects and waveforms. Capable of delivering tones that may get electronically misinterpreted through other techniques, this microphone reproduces sounds with a characteristic edge-softening quality and heightened sensitivity. The equipment is often sold with accessories such as shock mounts and windscreens.