MAKING A RIBBON MICROPHONE
PRODUCTION: MADE IN GERMANY
We are proud to say that we are one of the few manufacturers worldwide – and the only one located in Germany – to still manufacture ribbon microphones by hand. Ribbon microphones like our multiple award-winning M 160 really stand out from the crowd as far as their production is concerned, involving delicate workmanship and precision components.
Today, we will be going into detail about how we manufacture ribbon microphones at our Heilbronn site.
The centrepiece: das ribbon
The beating heart of a ribbon microphone is, of course, the ribbon. The ribbon is diaphragm and “coil” (the equivalent in a moving-coil microphone) in a single assembly with an extremely small mass. Double-ribbon microphones, as the name suggests, feature two overlapping ribbons.
Compared to most other manufacturers, we use extremely short and low-mass ribbons. What we lose in sensitivity because of this, we make up for with our special design.
But let’s look at things in the right order: What are the most important steps in the production of a ribbon microphone at our Heilbronn site? We looked over the shoulders of our production staff:
Productions steps:
1. The skeleton: assembling the magnetic structure
Permanent magnets and pole pates are stuck and screwed together to create a narrow magnetic gap with an extremely strong, defined magnetic field within which the ribbons can vibrate. This structure acts as the ribbon transducer’s “skeleton”.
2. Ribbon stamping
The extremely pure aluminium material is repeatedly rolled until it is only around 3 µm thin (corresponding to 0.003 mm). The material is then cut into coarse blanks and stamped into a special three-dimensional shape.
The extremely pure aluminium material is repeatedly rolled until it is only around 3 µm thin (corresponding to 0.003 mm). The material is then cut into coarse blanks and stamped into a special three-dimensional shape.
Any surplus material is then scraped off and the ribbon is ready.
3. Suspending the ribbons
The next step consists of suspending the two ribbons (beyerdynamic M 130 and M 160 double-ribbon microphones) within the magnetic structure so they can vibrate feely. These two ribbons overlap with a distance of around 0.5 mm between them. The lateral distance between ribbons and magnets is approximately 0.1 mm on each side.
Precision and accuracy are absolutely vital. The ribbons are inserted by our experienced production staff using microscope and tweezers. This precision work is crucial to the way the ribbons are allowed to vibrate, a factor that defines the sound of the microphone.
Precision and accuracy are absolutely vital. The ribbons are inserted by our experienced production staff using microscope and tweezers. This precision work is crucial to the way the ribbons are allowed to vibrate, a factor that defines the sound of the microphone.
4. Measuring
Measurements are taken inside an anechoic chamber under free-field conditions (i.e. in a space in which no sound reflections occur) to ensure each individual microphone conforms to the model’s specifications). Any previously unidentified problems (incorrect sensitivity, ribbon tension or contact with the magnetic structure) are detected here. In the case of errors, the ribbons must be inserted again.
5. Final assembly
The complete transducer system is integrated into the housing and the connector inserted and soldered. Finally, the upper basket is fitted and fixed to the basket ring with adhesive. The two red dots on the ring mark the longitudinal axis of the two ribbons in the M 160.
Each individual step requires the highest level of manual dexterity. From its very first inception, the (double) ribbon microphone has placed extraordinary demands on the people who produce it – from the precise strength of the pure aluminium ribbon and its exacting placement with micrometre accuracy within the magnetic gap to the testing of vibration behaviour.
This precision work is naturally reflected in the quality of the sound. Ribbon microphones are particularly popular on account of their untainted, natural reproduction of mid-range frequencies and their smooth, silky reproduction of trebles. In cases where high and fine resolution is required, when a condenser microphone might sound too “bright” or “analytical”, a ribbon microphone is a great choice.
Further reading:
Want to learn more about our “Made in Germany” approach? Find out here why we continue to manufacture products in Germany.
Whether your focus is on instruments or vocals, our premium microphones are perfect for use in the studio. Discover the best home-recording microphone for your purposes.
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