1 Microphones 6-195

Section1 PHOTO - VIDEO - PRO AUDIO Wired Microphones Introduction to Microphones ....8-9 AKG ...........................................10-25 Audio-Technica ........................26-50 Azden .............................................50 Audix ........................................51-57 Beyerdynamic ..........................58-65 Blue ...........................................66-69 Countryman.............................70-71 Crown .......................................72-85 DPA............................................86-93 Earthworks ...............................94-99 Electro-Voice ........................100-107 Neumann..............................108-123 Rode ......................................124-126 Samson .................................127-131 Sennheiser ............................132-141 Shure.....................................142-167 Sony ......................................168-171 Microphone Accessories .....172-195 INTRODUCTION TO SELECTING A MICROPHONE—THE BASICS Dynamic or Condenser? Reading Microphone Specifications One of the first things that you need to know before purchasing is The most common and useful specs for the microphone selection process whether you need a dynamic or condenser microphone. Inside each and are Polar (or pick-up) Pattern, Polar Response Graphs and Frequency every microphone is a transducer. This is the component which captures Response Graphs. These specs, in addition to, the most important decision sound by changing one form of energy into another. In this process factor of all, your ear, can tell you how appropriate a specific mic will be acoustic energy is transformed into electrical energy. Mic transducers for your application. utilize either dynamic or condenser transducer elements. Polar Patterns: Dynamic Microphones: One of the goals in microphone design is to make the transducer These fall into two main groups, ribbon and moving coil. All dynamic element more sensitive to sounds coming from a certain direction. Its microphones utilize the more rugged moving coil principle. This is like a directionality plays a key role the application it will be selected for — loudspeaker in reverse: a coil of wire connected to the microphone whether it’s capturing live vocals or a kick drum. A polar pattern diaphragm is held in a magnetic field. Sound waves change the pressure illustrates this directionality by showing the general sensitivity of a of the air they travel through. This causes the diaphragm to vibrate, thus, microphone from different directions using a 1 kHz (kilohertz) test tone. the coil moves in the magnetic field and an audio frequency voltage is This is sometimes referred to as “Rejection @ 1 kHz.” There are 5 induced. This signal is balanced, grounded and of low resistance and can common polar patterns: Omni-directional, Bi-directional or Figure-8, MICROPHONES be connected directly to the microphone input of a tape recorder or Cardioid, Super Cardioid and Lobar. mixing console without any electronics or supply voltage being needed in the microphone. Moving coil mics are extremely rugged and reliable. Omni-directional 360° coverage Consequently, they can be used in difficult working situations where Bi-directional Coverage from the front and rear of capsule more fragile microphones would not be suitable. The main uses are in broadcast reporting situations and in live stage work. Cardioid 180° coverage. No sound from rear. Super Cardioid 160° coverage. Slight pick-up from the rear. Condenser and Electret Condenser Microphones: Lobar 140° coverage. Off axis sound is highly attenuated 8 The condenser transducer is made up of two plates in a capacitor arrangement. The front plate is the diaphragm and responds to acoustic pressure changes. The back plate is fixed. An electrical charge is applied to either the front diaphragm or back plate depending on the design. As acoustic pressure moves the diaphragm, the capacitance changes between the plates and a voltage proportionate to the acoustic signal is produced. The electrodes used in electret (pre-polarized) condensers are manufac- tured from a special synthetic material. This material has a unique As you look at the representation of a microphone’s polar pattern you can quality, being able to permanently store an electric charge; the charge is see its ability to reject sounds from a given direction. The area where a thus ‘frozen’ in the electret material. No external polarizing voltage is mic completely rejects sound is its “null” point. A cardioid mic has a null required for the capsule and a low voltage power source can power the point that is directly to the rear of the mic. A super-cardioid mic or lobar remainder of the mic’s circuitry. In contrast to dynamic mic, electret mic has null points at its rear sides. Knowledge of a microphone’s null condenser mics can be very compact. This makes it possible to design point is paramount for proper mic placement relative to loudspeaker ultra-small clip-on lavalier mics, and small modular capsules. Back-electret arrays and other microphones. condenser mics use 48v phantom power (P 48) for external power. Polar Response Graphs: Polar response charts, like those shown at right, Dynamic Condensers vs. illustrate a mic’s pickup pattern at various Pros: Pros: frequencies. By comparing the size and shape of • Rugged • More sensitive the various frequency plots, you can get a good • Low self-noise • Better transients and frequency sense of a mic’s off-axis response or, how the mic • Lower Cost response discriminates frequencies hitting its capsule from • No power required • Useful small or large diaphragms different angles. The graph is drawn as if the mic • Less prone to weather and RF • Multiple patterns in one housing capsule was positioned in the center of the graph interference facing 0 degrees. To make polar plots less cluttered, Cons: only one side of each frequency plot is shown even Cons: • Higher self-noise though its pattern is symmetrical. Generally, • Lower sensitivity/output level • More fragile, more expensive directional mics become more omni-directional at • Slower transient response • Require power source lower frequencies. This is because higher frequencies • Usually larger and heavier • Prone to weather/RF interference have shorter wavelengths than lower frequencies and are easier to control in terms of their directivity. For Any Inquiries Regarding Your Order, Call Our Customer Service: (800) 221-5743 • (212) 239-7765 • FAX: (800) 947-2215 • (212) 239-7549 PHOTO - VIDEO - PRO AUDIO WIRED MICROPHONES SELECTING A MICROPHONE—THE BASICS Frequency Response Graphs: Microphone Setup and Miking Techniques Polar response graphs are often accompanied by frequency response graphs, which illustrate output levels of the microphone over its operating 3-to -1: range from lowest to highest frequency. The limits of human hearing are Whenever multiple mics are used in a stage setup, the 3-to-1 rule may be MICROPHONES contained within the frequency spectrum from 20 Hertz (cycles per employed to minimize phase cancellation. The rule states that the second) to 20,000 Hertz. As you look at the graph notice that these are distance between mics must be three times the distance from each shown from left to right along the bottom. The vertical figure on the left microphone and it’s sound source. The sound picked up by the more can either be a measurement of the relative response measure in decibels distant mic will be at least 12db less than the sound picked up by the (dB) [see MKH 40 Graph below]. In this scale, a 3 dB increase or decrease closer mic. Generally, the 3-to-1 rule is based on use with omni-direc- is considered to be noticeable to most individuals and a 10 dB change is tional mics It can be relaxed to some extent for unidirectional mic use. considered to be twice as soft or twice as loud as the original sound. Other graphs will use a dBv scale as a means of expressing the output Stereo Mic Techniques: voltage of a microphone at different frequencies [see MD 421 II Graph Stereo miking refers to a number of miking setups where we position below. The flat response of the MKH 40 will have a more neutral character and aim usually two microphones to capture left-to-right soundscapes and is suitable for a wide range of applications. The peaked response of of one or more sound sources. The auditory nerves inside our ears can the MD 421 II in contrast shows a mic with a “presence peak” beginning detect phase and amplitude differences from played back sounds at around 2 kHz to add emphasis to upper mid-range frequencies and recorded in stereo. This allows us to localize sounds that are wider, increase vocal intelligibility. Also, certain mics feature bass roll-off spacious and more pronounced in the mix. Stereo miking is sometimes switches which attenuate low-end rumble without altering the general used when the size of an ensemble makes close-miking impractical. character of the microphone. These roll-off effects will also be illustrated There are four common miking arrangements for stereo recording: XY or on the graph by dashed lines. Coincident Pair, Near Coincident Pair, Spaced Pair and MS (mid-side): XY or Coincident Pair: XY miking uses two directional or cardioid mics 9 angled between 90 and 135° apart and placed as close together as possible. Sound hits both mic capsules at the same time, hence the term coincident to describe the technique. However, sounds to the left or right of center hit one mic on-axis and one mic off-axis resulting in an audible level discrepancy between both capsules, creating a stereo image. Near Coincident Pair: The only difference between XY and Near Coincident Pair stereo miking is the introduction of space between both Sensitivity: mic capsules. This effectively creates a time difference and level difference The rating of a microphone’s output voltage for a particular SPL input. between both receiving capsules. The result is a well-defined stereo image Sennheiser mics are subjected to 1 kHz sine wave at a level of 1 Pascal that has more depth and sharpness than a coincident pair. There are sev- which is the same as saying 94 dB SPL.

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