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How to choose the right broadcast microphone by Ralph Dunlop, Sound Network What are the most common types of microphones for broadcast use and how far has microphone technology progressed in the digital world? Traditionally the most popular microphone used in broadcast and film sound recording was the “Boom” mounted mic. The problem with older boom microphones was getting the mic close enough to the artist without it appearing in shot or casting a shadow over the performer. This changed somewhat when highly directional shot gun microphones were developed as these allowed engineers to achieve much higher sound levels while further away from the performer, but in some circumstances getting the shot without seeing the microphone hovering in mid-air could still be a problem. In the 1950’s and 60’s the ‘lavalier’ microphone was developed for studio use, giving performers a greater degree of mobility whilst maintaining a constant distance between the source and microphone. These, however, were hardly discrete, and were little more than a dynamic vocal mic on a string hung round someone’s neck. As with all modern recording technology, microphone design is now a highly sophisticated art-form. With the right microphone, professional recordists can achieve the most superb and natural sound quality in the most challenging of circumstances. Continuing miniaturisation of the product has also been demanded by the visual industry and companies like DPA have been responsible for pioneering new technology and production techniques to create very high quality microphones in ever decreasing physical profiles. What are the advantages of a body worn microphone over a traditional shotgun microphone? Today, the choice of microphone is very much dictated by the working environment and application desired. For example, body worn mics with wireless microphone systems are almost exclusively used in broadcast studios by presenters, allowing complete flexibility of movement and great sound quality. Being so small, body worn mics can get closer to the sound source and be hidden easily. When choosing a lavalier microphone what should I be aware of? Analogue sound is still at the mercy of the laws of physics. Even Newton and Einstein couldn’t find a way of changing these, but what we can do is work with these limitations to produce the best solutions for the best possible results, depending on the environment and application. DPA currently have miniature microphones available with a selection of pick up patterns and a variety of sensitivities enabling the professional engineer to tailor the microphone for every situation. There are basic criteria that a sound engineer must consider when choosing any type of microphone, especially body worn transducers: Sensitivity - Sensitivity tells you how well the microphone can convert the acoustic sound into electricity. Sound pressure level (SPL) handling & total harmonic distortion (THD) SPL handling tells you how much sound pressure in dB the microphone can handle before it either clips (the diaphragm hits the backplate or the amplifier overloads) or reaches a certain level of distortion (THD or total harmonic distortion). Typically this level is either 0.5% or 1%, and the higher 58 | TV-BAY MAGAZINE: ISSUE 77 MAY 2013 TV-BAY077MAY13.indd 58 02/05/2013 21:19