【 Weak current college 】 technical characteristics and reasonable choice of microphones---Power By 【 China power house network 】

Understanding the technical characteristics and reasonable choice of microphones
Choosing the right microphone is becoming increasingly difficult. Microphone types more and more possibilities and quality are excellent. So when selects and purchases the biggest factors in addition to the price, is a personal preference.
For those who purchase preferences depend on an objective parameter instead of subjective impressions, here are some tips for buying a special-purpose microphone reference, these applications include radio, sound recording or live broadcast (with or without reinforcement).
First and foremost, of course, is the smoothest response
Select the microphone, the user first should be concerned about its frequency response. Frequency response must be sufficiently broad to pick up the entire range of sound, the natural sound source quality does not have to listen to changes.
The second step is to select the directional microphone
At the same price as the microphone, the microphone is usually has the most spacious and most smooth response while breathing, handheld noise and wind sensitivity is lower. If no excessive external noise or too much reverb, they are very suitable for most applications. For example, a moving coil microphone, Omni interview at the press has been widely in use.
Although Omni microphones to accept messages from all direction of sound waves, but some users may prefer to accept from a single (one-way) or two (bi-directional, 8 glyphs) direction of sound waves. This means that in order to obtain direct sound and the sound the same as the rate of mixing, heart-shaped and bi-directional microphone, heart-shaped microphone and acute heart-shaped microphone location away from the sound source are all of the distance to the microphone location away from the sound source distance 1.7 times, 1.9 times and 2 times. For example: using a microphone to pick up a distant sound source, capacitive interview microphone can distance gets clear target sound, usually for large Orchestra spot during recording.
A third of the electricity output impedance is very important
As it should and mixer, tape recorder or amplifier input impedance matching. This impedance is Ω, usually in the frequency of 1kHz. Moving coil microphone typical impedance value of 150 Ω Ω, 200 or 300 Ω. As a rule of thumb, the device's input impedance should be at least 3 times the microphone impedance. All currently available meet the requirements of a mixer.
In addition, there are high impedance microphone and can be used in low-and high-impedance switch between dual impedance microphone. And high impedance microphone connected to the cable length should not exceed 7m, because cable capacitor causes high frequency attenuation.
Built-in amplifier microphone can be inserted into the greater than or equal to the minimum load impedance of any load. If the microphone is connected to one less than the minimum load impedance of the load of input, frequency response will be compromised.
Fourth overload main sound pressure is very important for capacitive microphone
Capacitive microphone work in one until a sound pressure level (SPL) of linear State, the SPL is called overloading or maximum SPL, frequency is usually 1kHz. Sound pressure exceeds this value, the output signal will be because of the harmonic distortion.
At maximum SPL, total harmonic distortion factor should not exceed 0.5% or 1%. In a typical application is not possible to overload a moving coil microphone, they actually never enable signal distortion.
Sensitivity is an SPL of microphone output voltage. It generally 1kHz measurement, unit is V/Pa or dBV. A gain setting, a sensitive microphone sound production is large, but the user should now use carefully, because the feedback risk is increased in proportion.
The fifth proximity effect
Proximity effect is used near the sound effect of skills upgrading the bass, the microphone is placed away from the source location of a few centimeters. Although on some occasions this effect will produce some singers like strong voices of fullness, but there are a number of occasions the need to control or completely avoid bass boost, for example, in the records of the conversation. Proximity effect may make your conversation may not understand. Some microphone equipment a bass filter to compensate for the proximity effect, applications in the home recording can avoid sunlight tube transformers, refrigerators, air conditioners, electric low-frequency noise.
In the sound recording or broadcast performances, working distance is usually very close, close to the transmission of technology will have a place. The aim is to prevent acoustic feedback.
In the Studio like this technology is not required, remote acoustic technology dominate. Therefore, in the Studio might use a moving coil and capacitor microphone. Capacitive microphone on transient sound with excellent response. When the speaker has excessive sizzled when moving coil microphone than capacitor microphone.
There are the most important use of the microphone. To help the end user should have a choice: this microphone is used for broadcast and studio recording, or used for broadcasting or stage recording (with sound)?
For broadcasting or Studio voice record, sound will be used for remote microphone. As for broadcasting or stage recording (with sound), you will need suitable for near-audio microphone. In the near of the sound, the user should decide which kind of microphone is best used before deciding whether to require proximity effect.
Next, the microphone is to close to people, if yes, should the hanging microphone and other dedicated microphone (such as a headset microphone) to choose between. The neck hanging microphone and any special low noise (microphone enclosures and cable friction) isolation is very important.
In use on non-professional speakers (such as Studio guests) clothes neck hanging microphone, sound engineer should tell speaker do not inadvertently encounter might tie pins or necklace microphone on, otherwise the audience may hear very annoying squeaks.