【 Weak current College 】 microphone selection

Gradual microphone selection

Choosing the right microphone is becoming increasingly difficult. Microphone type more and more, each have their own strength, quality 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 choosing the reference of special-purpose microphone, these applications include radio, sound recording or live broadcast (with or without reinforcement).

The smoothest response

Select the handset, the user should concern the brunt of the frequency response. Frequency response must be sufficiently broad to pick up the entire range of sound, natural sound source quality does not have to hear the change.

The next step is to select the polarity of the graphic. At the same price as the microphone, Omni-directional microphone 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, AKGD230 moving coil microphone's Omni has been widely in use.

Although the omnidirectional microphone 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 superb location away from the heart-shaped microphone sound source distance are Omni-directional microphone location away from the sound source distance 1.7 times, 1.9 times and 2 times.

Power 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 x 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 handset 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.

Sound flat major on the overload of capacitor microphone is important. 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 level 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.

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 handset equipped with bass filter to compensate for the proximity effect, such as SennheiserMD421 and MD441, AKGSolidTube and C414B-ULS.

There is also a certified is the proven solution. Electro-VoICe owns a patent for design Variable-D microphone, in this design eliminates the proximity effect resulting in direction of a very strong heart-shaped microphone. Variable-D hyper-heart-shaped microphone RE16 and heart-shaped microphone RE20 in working distance change maintain smooth bass frequency response, which improves voice clarity.

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 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 close to the sound of the receiver. 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 close to the person, if yes, should the hanging microphone and other dedicated microphone (such as a headset) 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 on microphone, otherwise the audience may hear very annoyingPeople scream.