As a Visual artist i have always shied away from the Development in Audio Industry except for a few tricks (absolutely on a need to know basis).However at my day job we have been developing some Audio Visual support Media for our clients that required some crisp quality Voice recording. I found my consumer microphone to be absolutely inapt at such a task and this instigated me to do some research on this topic. What i found was a real eye opener and i am sure this info should help prosumers like me to get a jump start towards understanding Microphones.
A microphone, sometimes referred to as a mic, is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, hearing aids, motion picture production, live and recorded audio engineering, in radio and television broadcasting and in computers for recording voice, VoIP, and for non-acoustic purposes such as ultrasonic checking.
The most common design today uses a thin plastic or metallic membrane called diaphragm .It is usually round, always thin, and hopefully very light in weight. Some microphones have a diaphragm up to 25 mm (one inch) or more in diameter. Others have diaphragms as small as 3 mm (around one eighth of an inch). The Diaphragm vibrates in response to sound pressure/vibrations from the air movement which is subsequently translated into an electrical signal. The size of the diapragm dictates the quality of the frequency of the signal and is one of the prime selection criteria.
- Large Diaphragm Microphones - Large diaphragm microphones (LDMs) are generally the choice for studio vocals, and any instrument recording where a more “deep” sound is desired. A large diaphragm microphone generally warms up the sound of what it’s recording, which also leads to the myth that most LDMs reproduce low frequencies better than small diaphragm mics; this isn’t true, in fact, small diaphragm mics are much better at reproducing everything evenly, including bass. You’ll want a pop screen if using a condenser microphone for vocals; they’re so sensitive to transient noises that the “P” and “SH” sounds you make will cause distortion.
- Small Diaphragm Microphones - Small diaphragm microphones (SDMs) are generally the best choice where you want a solid, wide frequency response and the best transient response, which as we mentioned before, is the ability for your microphone to reproduce fast sounds, such as stringed instruments. SDMs are also the preferred choice for concert taping.
As a general rule, large-diaphragm microphones can be subjectively very good for vocals and single instruments on-axis. For general room pickup, the more accurate small diaphragm type is preferred.
Another very crucial thing to take into consideration is the Sound Pick up Pattern.Microphones pick up a range of noise in four patterns. The different types are:
- uni-directional or cardioid: picks up sound in a heart-shaped pattern in one direction. They generally record sound around them but not directly behind them. These are the best type to use.
- omi-directional: pick up sound coming from all directions.
- bi-directional: pick up sound from two opposite directions.
- hyper-directional: pick up sound from one direction only and have a very narrow field.
In the Market , you will come across a wide array of mics based on technology such as electromagnetic induction (dynamic microphone), capacitance change (condenser microphone, pictured right), piezoelectric generation, or light modulation to produce the signal from mechanical vibration.However the Condenser and Dynamic Microphone are the most popular kind.
Condenser MicrophonesThese are the most common types of microphones you’ll find in studios. They have a much greater frequency response and transient response - which is the ability to reproduce the “speed” of an instrument or voice. They also generally have a louder output, but are much more sensitive to loud sounds.They are generally much more expensive than dynamic microphones. They require the use of a power supply, generally 48 volt “phantom power”, and that’s supplied very easily by most mixing boards or external power supplies (look for a switch that says “P 48″ or “48V” on the channel strip or on the back of the mixer.)
Heil PR40 is a great example of a Condenser MicrophoneDynamic MicrophonesCompared to condenser microphones, dynamic microphones are much more rugged. They’re also especially resistant to moisture and other forms of abuse, which makes them the perfect choice onstage. Dynamic microphones like the Shure SM57 and Shure SM58 are legendary for not only their good sound quality, but the amount of abuse they can withstand. Any good rock club probably has at least 5 of each of these microphones in various states of aesthetic ruin; however, they still turn on and more than likely sound just as they did the day they came out of the package.
Dynamic microphones don’t require their own power supply like condenser microphones. Their sound quality is generally not as accurate, however. Most dynamic microphones have a limited frequency response, which makes them well-suited, along with their ability to withstand high sound pressure levels, for loud guitar amps, live vocals, and drums.
Shure SM58 is one of the highest selling Product in this category.
Tue, Jun 30, 2009
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