It used to be that the price of the mic was a direct reflection of it’s quality. In the past few years, many microphones are available at a much lower price and perform quite well for their intended application. Most of these lower priced mics copy the basic structure of their more expensive counterparts.
WHAT TYPE OF MICROPHONE IS BEST?
Before you can answer this question, you have to decide how you are going to use the mic. Will you use it for live vocal performances like in a band setting? Is it for recording? Will you use it to mic an instrument? Maybe you’d like a multi-purpose mic. Once you decide on the application of the microphone, you can narrow your search considerably.
WHAT DO THE SPECS MEAN?
If you get a basic understanding of the specs and terminology, selecting the right mic will ne an easier task. Take some time and read the following:
POLAR PATTERN: The polar pattern is the shape of a mic’s field of sensitivity or the directions from which the mic accepts or ignores incoming sound. An omnidirectional microphone responds to sounds coming from all directions. A bidirectional mic picks up sounds from east and west while excludinf sounds from the north and south. A unidirectional mic hears sounds from one direction and ignores sounds from other directions.
The most common microphones are unidirectional and they come in three polar patterns: cardioid, super cardioid, and hypercardioid. All three are patterns that reject sounds coming from behind the mic or from the sides. The cardioid pattern is roughly a heart shape, which makes the mic more sensitive to sounds coming from straight on or from the sides, but rejects sounds 180 degrees opposite the direction the mic is pointed. Supercardioid microphones accept accepts a little more sound from a 180 degree direction, but rejects more from each side. The hypercardioid allows yet more sound from 180 degrees, but rejects more of the sound coming from 90 or 270 degrees.
Polar patterns for these types of microphones are very important if you use the mic in a noisy setting like a singer’s mic in a band setting. The cardioid, supercardioid and hypercardioid mics will tend to exclude all sounds except the singer’s voice which results in a less “muddied” sound and allows more gain before feedback occurs.
Some condenser microphones are multi pattern and their polar pattern can be changed either by means of a switch or by interchangeable capsules from one pattern to another-from omni to cardioid, for example. Having a mic with this feature makes for a much more versatile microphone, especially in the recording studio.
FREQUENCY RESPONSE: This is the range of frequencies from low to high that a microphone will respond to. These frequencies are stated as a range such as 80hz to 15khz. A good vocal mic would have a frequency response in this range. If you needed a mic for miking snare drums and toms, look for a mic with a range that starts around 50hz. Lower sounds like a kick drum a low end of 30hz to 40hz is desirable.
RESPONSE CURVE: Frequency response only tells you the range a mic can reproduce, but the response curve refers to the shape of it’s frequency responsiveness. Starting at zero on the low end and dropping off at zero on the high end, it takes the form of a curve when applied to a graph. In this curve there will be peaks and dips at certain frequencies that give the microphone a certain character, thus making it more suited for certain applications.
EXAMPLE: A mic intended for vocals may have a spike in it’s upper midrange, thus resulting in a smoother more intelligible sound reproduction.
SPL and Sensitivity: How quiet a sound a mic can pick up is referred to as the mic’s sensitivity. Since a microphone’s sensitivity is measured by different systems, for the less experienced user it is probably enough to know that the lower the number, the more sensitive a microphone is. SPL stands for sound pressure level and is expressed in dBs. A mic’s SPL describes the maximum volume of sound that the mic can handle. In a way, this is the opposite of sensitivity. This is of the utmost importance if the mic must deal with loud instruments. Average SPL level is around 100dB and a high SPL is 130dB.
In addition to the specs there are other factors that determine the characteristics of microphones. Manufacturing precision can affect a mic’s performance. As a result of this, some of the lesser expensive microphones aren’t consistent in their sound reproduction. How the mic is built and the kind of metal used also effect a microphone’s performance. Listening to similar microphones is the best way to choose the one best suited to your needs.
WHAT ARE THE DIFFERENT TYPES OF MICROPHONES AND HOW ARE THEY USED?
Microphones usually fall into one of two categories: Dynamic or Condenser. Dynamic mics do not require a power source, while condenser mics do. Further explanation of this follows, so pay particular attention to this next segment.
DYNAMIC MICROPHONES: Dynamic mic’s usually have a high SPL capacity. They are extremely rugged and have a polar pattern that rejects off-axis sounds. Since they have internal shockmounting, they tend to be used for live sound applications like vocals and instrument miking, but some are also used for recording. (The Shure SM57 has been a staple of both the studio and the stage for a long time.) Dynamic mics are usually affordable, and additionally, many manufacturers have introduced economy series mics that offer great performance at a budget friendly price.
Dynamic microphones use an inductive coil connected to a diaphragm that’s placed within the field of a permanent magnet. As the diaphragm moves, it moves the coil, thus varying the voltage the coil produces.
CONDENSER MICROPHONES: A condenser mic will have either an external power supply, use phantom power or have internal batteries. Newer mixers will have phantom power, but if you have an older mixer, check to see if it has phantom power before buying a condenser microphone. If the mixer does not have phantom power, free standing external phantom power units can be purchased to accommodate condenser microphones.
While most condenser mics are used for recording, there are some that are used for live sound applications such as miking pianos and acoustical string instruments. Other applications include overhead miking of choirs and cymbals.
Many condenser microphones have roll-off and attenuation switches used to enhance a certain mic’s versatility. The roll-off switch alters the frequency range, usually on the low end, reducing response or cutting it off below a certain level. This is used in live situations to reduce low-end rumble and to increase an amplifier’s efficiency. Lots of amplifiers don’t produce very low end sounds, but they use up power trying to. Rolling off the bass keeps the PA power amp from having to deal with frequencies that are below it’s capability. In recording, rolling off the bass results in added clarity. Attenuation switches alter a mic’s sensitivity or volume, so that high volume sources won’t overload the microphone.
LARGE DIAPHRAGM CONDENSER MICS: These mics have diaphragms from three quarters to an inch in diameter. They are very sensitive and require external power and shock mounts. Since they are large and so sensitive, they are unsuited for miking live performances, but are excellent for recording voices and many instruments. These can be very expensive, but recently many manufacturers have been producing more affordable large diaphragm condensers designed like the expensive models and work quite well for nonprofessional recording.
SMALL DIAPHRAGM CONDENSER MICROPHONES: These do especially well in reproducing higher frequency sounds and sound sources that change quickly in volume. They have a diaphragm that is one-half inch or less in diameter and are used in both recording and live performance applications. They require phantom power or a battery to operate. These are well suited for overhead miking of cymbals.
SHOTGUN MICROPHONES: This style of mic has a narrow and extended polar pattern. They are used mainly for broadcasting because they excel at picking up specific sound sources from a distance. Pic of shotgun mic
SUMMARY: Do as much research as you can before purchasing a microphone. Most manufacturer’s web sites are full of information and specs on their products. You’ll be amazed, and maybe a little confused with all the choices available, so take your time when choosing a microphone. For further assistance contact any West Music store and one of our knowledgeable Associates will be glad to assist you.
(FOR INFORMATION ON WIRELESS MICROPHONES CHECK OUT OUR “WIRELESS MIC BUYING GUIDE” )