Question

Studying sound engineering and music technology, need help?

Hi i'm doing a course in sound engineering and music technology. I've never done this before and in class we get most of the time a crash course and i have to learn as much as i can. We do a lot of theory and not enough practical which i would like to do and i need to pass the first part of the course to get to the next otherwise i don't get on. We started learning about microphones. Can someone explain the difference between a dynamic mic and a condensor mic good and bad points which microphone is used for what and what is polar pattern and what part of the microphone is the capsule. Also what is impeadence, what does that mean. Is a cardiod microphone directional mics or something like that and also transient response what is that also. I get confused so can someone help please. Thanks.

Answers

1. Dynamic mics work through electromagnetic induction. This means they have a coil of wire within them that, when shaken by sound, moves within a magnetic field. The magnetic field disturbs the electricity running through the mic and this disturbance is then either converted back into sound at an amplifier or made digital at an analog to digital converter.

2. Condenser Mics work through electrostatic induction. They require phantom power to operate. This power runs through the microphone and creates an electric field between two plates. When sound vibrates the plates the electric field transduces the sound waves into waves in the electric field.

3. Since dynamic microphones use a heavy coil for their transduction, they can take very high SPLs. They are not great for quieter material though because it takes a lot of sound to get the coil moving and the noise floor can come up very quickly. They also have a slower transient response for the same reason. They are subject to what is known as the proximity effect, where a microphone placed close to a sound source wlll get a huge boost in low frequencies. This can be a positive or negative effect, depending on what you're going for. Condenser microphones are normally not meant for SPLs that are quite as high as the dynamics, They do have an excellent transient response though. They tend to pick up brighter, airy-er sounds better.

4.Polar pattern refers to what spots a microphone picks up and rejects. The 5 main patterns are Omni, sub-cardiod, cardioid, super and hyper-cardioid, and figure 8. Omni picks up sound equally in all directions. Cardioid picks up very well in front with good side and rear rejection. Figure 8 picks up equally in the rear and sides with superb side rejection. The other 3 are transitional variations between these 3.

5. The capsule is the part of a microphone the "hears" sound.

6. Impedance is how well current flows through a wire. It's very similar to resistance.

7. Cardioid mics are fairly directional. As stated above, they pick up mostly in front, with good rear and moderate side rejection. They're called cardioid because their polar pattern looks like a heart, with the top part of the heart being the rear, and the bottom being the front.

8. Transient response is how quickly a microphone reacts to a sudden increase in sound pressure, or a "transient".

Pheww. Hope that helped :)

-KDecka

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