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Contents Microphone Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Microphone Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Capsule Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 The Backplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Chapter 1 Microphone Design While all microphones are designed for the common purpose of converting variations in sound pressure to electronic signals, different technologies have their benefits depending upon the application.This chapter examines the merits of different design types, capsule sizes, polar patterns, electronics and more. Microphone Types The three main types of microphones in common use today are dynamic, ribbon and condenser. Each has unique attributes appropriate for different
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fixed magnet have very low output, thereby requiring more electronic gainÑa factor that necessitates high-quality preamp electronics in order to avoid noise. ultra -thin diaphragm Condenser microphones capacitance Condenser mics are the most common for studio use. A thin electrically conductive diaphragm is suspended over a back plate, solid backplate forming a delicate flexible capacitor.When sound waves excite the diaphragm, the distance between the diaphragm and back plate output signal chang
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Small Capsules Small capsules are typically those with diaphragm diameters of less than about 1/2Ó. Categorically, they are extremely accurate through the audible range of 20Hz to 20kHz.Their poor signal-to- noise ratio, however, requires tricks with electronics and relegates small capsules to being most useful for measurement rather than recording. Medium Capsules Medium capsules have diaphragms that are approximately 1/2 inch to 3/4Ó inch in diameter. Given the right design and manufacturing,
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screw/contact invariably prefer the sound of solid brass. Needless to say, resonator disk we use solid brass backplates in all M-Audio mics. disk spacer backplate screws The spacing between the diaphragm and backplate is diaphragm critical. In order to avoid problems with barometric w/ mounting ring pressure, the spacer ring has a break in order to allow air ring spacer to move freely between these two components. We precision drill approximately 100 extremely fine holes in center spacer the
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Omni also exhibits significantly less proximity effect than cardioids. One result is that omnis are somewhat less sensitive to the movements of an animated vocalist. Another is that omnis tend to have less need for EQ. As mentioned earlier, while omnis pick up 360 degrees of sound, they tend to be more directional as frequencies increaseÑespecially in larger capsules. Figure 8 or bidirectional pattern The figure 8 or bidirectional pattern is equally sensitive on the two opposing faces of the m
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signal through headphones.That’s because one side of the mic is in phase with the performer (and therefore reinforcing their perception of their own sound) while the other side is not. Addressing the in-phase side while monitoring produces optimal monitoring results. Top Address vs. Side Address Designs top address The orientation of the diaphragm within the head of the microphone determines if the microphone is addressed from the top or the side. While not an absolute rule, side address mediu
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An output transformer and/or amplifier serves as a sort of translator and, in audio, we expect that translation to be excellent in order to maintain frequency response, dynamic range, and signal-to-noise ratio. Just as a professional language translator costs more than someone who just took a few years of foreign language in high-school, pro-quality output transformers and amplifiers cost more than garden-variety ones. (A single transformer like those used in each channel of pro consoles and out
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still work.) The theory there is that the tube is used as a sort of processor to “warm” up the sound.The reality is that these are still solid state mics masquerading as tube mics as cheaply as possible. Because of the physics behind tube operation, tube mics have classically been subject to certain physical restriction on the length of the cable between the microphone and power supply. As a result, tube mics are normally restricted to cable lengths of about 15 feet.This has sometimes required t
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From a technical perspective, the two mics need to be as identical as possible in frequency response. A ÒflatÓ frequency response implies that there is no deviation in the output level versus the input level at any and all frequencies across the audible spectrum. While a flat frequency response is theoretically ideal, it is rarely achieved completely in any audio component. For example, a mic might exhibit a 1dB boost at 1kHz and start rolling off 3dB per octave at 14kHz.A perfectly matched pair
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Choosing & Using Microphones 12
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Chapter 2 Caring for Microphones High-quality condenser mics like the M-Audio line represent an investment. A few basic tips will help ensure a lifetime of excellent performance. Shock Protection As you now know, condenser mics are constructed with extremely thin diaphragms and very high tolerances. As such, condensers should be protected from abuse, especially physical shock. (M-Audio capsules are rubber-mounted internally, but the need for caution still applies.) Keep condenser mics away from
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Cleaning and Storage Always store a condenser microphone in its case when not in use. Particulate matter such as dust can attach itself to the diaphragm and cause degradation of performance over time. In most cases, wiping the metal exterior of a microphone down with a dry or slightly damp rag will be sufficient to remove dust, dirt, fingerprints and the like. In the event that further cleaning is necessary, spray a non-abrasive household cleaner such as Fantastik or Formula 409 onto a rag and
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Chapter 3 Basic Miking Concepts Microphone placement is an area in which art meets science. Microphone choice and placement is somewhat subjective, much in the same way that choosing a guitar and amp is a matter of personal preference. Furthermore, each situation brings a difference confluence of performer, sound space, recording equipment and creative forces.The question is not one of using the right or wrong mic or technique, but simply one of what works best in each unique situation. Nonethel
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a proximity effect where the low-mid frequencies increase as the distance between the source and mic decreases. (The proximity effect is not a big issue with omni patterns or medium-sized capsules of any pattern.) With large diaphragms, then, the placement of the mic affects volume, room ambiance and tonality. Large Capsules vs. Medium Capsules You can achieve excellent results in most situations using our large-capsule mics. As a rule of thumb, the large-capsule mics like ours will have more se
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The Recording Environment Professional studios often have several different acoustic spaces availableÑfrom small, relatively dead isolation booth to cavernous rooms with natural reflections and long delay times. Home recordists have fewer options, yet experimenting with recording in different rooms may yield interesting results. Large rooms and tall ceilings will give a more open sound than small rooms and low ceilings. The amount of furniture and reflectivity of various surfaces is also an in
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common acoustic damping materials for home studio use. Music stands can also be reflective Ñ something you can compensate for by simply draping towels over them. While a reasonable amount of absorption is often desirable for isolation, too much damping can create an anechoic space that literally sucks the life out of a recording. In more permanent project studios, consider creating a flexible acoustic environment. One solution is a series of gobos or movable panels with a reflective surface on
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Minimize reflective surfaces. Hard surfaces like wood floors, smooth walls, windows and mirrors are a common culprit in phase issues because they reflect sound back into the microphone. If things sound odd, try moving the performer and/or mic. Also experiment with damping those reflections with blankets, towels, baffles and the like. Avoid boxing in mics. Microphones typically need a little breathing room in order to avoid reflection. Omnis placed in a corner, for example, often sound like theyÕ
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Choosing & Using Microphones 20
