How Does a Ribbon Mic Work

A 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.

 

Care and Feeding of Ribbon Microphones

By Wes Dooley

We recording engineers often swap stories about tough lessons we've learned: We remember when we didn't record a rehearsal that was the best performance. We learn that media is cheap and performance magic is unpredictable.

 

Weird Ribbon Mic Tricks

By George Petersen

A ribbon mic in front of a kick drum is a recipe for disaster, as the drum's enormous air pressure can instantly distort/destroy the mic's sensitive ribbon. However, you can often get a huge yet safe kick sound by laying a ribbon mic on a pillow inside the drum, with the mic's element pointing straight up toward the ceiling so the air flows across (and not into) the mic.

For guitar overdubs, try putting a ribbon (or other figure-8 mic) between two 412 cabinets that face each other. As the back side of a figure-8 mic is out-of-phase with the front, wire one of the 412s out-of-phase, experiment a bit with mic-to-cabinet distances and you've got a massive guitar sound like no other!

Please note that if hiring a microphone from Audio Analysis or AA Masters or Marcus Wilson Studio Hire that under no circumstance are you aloud to try this with any of our microphones, if you get the placement wrong you will destroy our microphone and you will be fined with the cost of replacing that microphone- not just the ribbon.

 

Microphone Catalogue
Rack Mount Catalogue
Care of Microphones
How Does a Ribbon Mic Work
Weird Ribbon Mic Tricks