Microphones 101 - The DSF production compendum
Posted: Wed Apr 07, 2010 12:51 am
Ok, so this is a topic that I'm sure comes up time to time on electronic music based forums, but since most people tend to do most things in the box and rely on samples or plug-ins rather than traditional recording techniques, recording their own samples, or creating their own distortion, reverb, delay etc with the simple use of a microphone(s). So without further ado lets get to it ladies and gents.
The Three Types of Microphones
Dynamic (Moving Coil)
Think of these as the basic mics you see in live applications or if you ever had an electronics kit as a kid the reverse speaker style. You have a diaphragm connected to a spooled coil of fine wire. This piece is placed over a magnet with a circular channel cut into it that the coil sits in. As sound waves move the diaphragm... well without getting into electrons and magnetic displacement yada yda yada (if wanted I can edit this to be uber technical) this is what translates the sound waves into electrons which can be sent through the preamp built into the mic to the other end of whatever you're plugging into. How often the diaphragm changes direction is what gives the frequency/pitch, how far it travels in a given instant determines how great the output signal will be (loudness)
Note that what makes the difference in dynamics is going to be the material the diaphragm is made out of, thickness, how it it is hinged (so it can move), the size and weight of the coil etc. EX: the Shure SM-57 and SM-58 are the same identical mic, just the SM-58 has a windscreen capsule over it making it ideal for vocals
Ribbon
The diaphragm on a ribbon mic is the conductor in this case breaking the lines of force in the magnetic field. It's called a ribbon because the diaphragm is a thin corrugated pieced of metal which is placed between two magnetic fields of opposite polarities. So as it vibrates the fields are broken and more of that technical voodoo of making sound waves into electrons happens. Well that's pretty simple you say... not quite. The downside to ribbon mics is that they need to have a very thin piece of metal in order to vibrate and long enough so that the vibrations can be detected enough to translate over well. What does that mean... drop it chances are you'll need to replace the ribbon. Push too much SPL through it, you'll probably need a new ribbon. Up until recently the one downside was the output level on ribbon mics, which has been addressed in more modern ribbons. Ribbon mics are more compliant, less mass, and for the most part have better transient response than a dynamic. The longer the ribbon, the better the low frequency response; the shorter, the better the high frequency response.
Condenser
Condensers may as well be called a capacitor for those of you familiar with electronics. This is also why with condenser mics you need to provide them with their own power source (phantom power aka +48v). Inside the mic you have a fixed rear plate and a thin front plate (the diaphragm), now here's where it gets kinda crazy. The thin movable plate is generally 3-10 micron (a human hair is generally 40 micron) thin piece of mylar that has been spattered with a spray of silver, gold, or nickel alloy to make it conductive. As the diaphragm moves that technical mumbo jumbo occurs to translate sound waves into electrons. Now without getting technical about the electronics even with the phantom power a condenser has a preamp very close to the capsule in order amplify the constant change in voltage across the resistor. In other words without the built in preamp in the mic itself the signal wouldn't be strong enough to be sent.
Next: Pickup Patterns
to be continued...
The Three Types of Microphones
Dynamic (Moving Coil)
Think of these as the basic mics you see in live applications or if you ever had an electronics kit as a kid the reverse speaker style. You have a diaphragm connected to a spooled coil of fine wire. This piece is placed over a magnet with a circular channel cut into it that the coil sits in. As sound waves move the diaphragm... well without getting into electrons and magnetic displacement yada yda yada (if wanted I can edit this to be uber technical) this is what translates the sound waves into electrons which can be sent through the preamp built into the mic to the other end of whatever you're plugging into. How often the diaphragm changes direction is what gives the frequency/pitch, how far it travels in a given instant determines how great the output signal will be (loudness)
Note that what makes the difference in dynamics is going to be the material the diaphragm is made out of, thickness, how it it is hinged (so it can move), the size and weight of the coil etc. EX: the Shure SM-57 and SM-58 are the same identical mic, just the SM-58 has a windscreen capsule over it making it ideal for vocals
Ribbon
The diaphragm on a ribbon mic is the conductor in this case breaking the lines of force in the magnetic field. It's called a ribbon because the diaphragm is a thin corrugated pieced of metal which is placed between two magnetic fields of opposite polarities. So as it vibrates the fields are broken and more of that technical voodoo of making sound waves into electrons happens. Well that's pretty simple you say... not quite. The downside to ribbon mics is that they need to have a very thin piece of metal in order to vibrate and long enough so that the vibrations can be detected enough to translate over well. What does that mean... drop it chances are you'll need to replace the ribbon. Push too much SPL through it, you'll probably need a new ribbon. Up until recently the one downside was the output level on ribbon mics, which has been addressed in more modern ribbons. Ribbon mics are more compliant, less mass, and for the most part have better transient response than a dynamic. The longer the ribbon, the better the low frequency response; the shorter, the better the high frequency response.
Condenser
Condensers may as well be called a capacitor for those of you familiar with electronics. This is also why with condenser mics you need to provide them with their own power source (phantom power aka +48v). Inside the mic you have a fixed rear plate and a thin front plate (the diaphragm), now here's where it gets kinda crazy. The thin movable plate is generally 3-10 micron (a human hair is generally 40 micron) thin piece of mylar that has been spattered with a spray of silver, gold, or nickel alloy to make it conductive. As the diaphragm moves that technical mumbo jumbo occurs to translate sound waves into electrons. Now without getting technical about the electronics even with the phantom power a condenser has a preamp very close to the capsule in order amplify the constant change in voltage across the resistor. In other words without the built in preamp in the mic itself the signal wouldn't be strong enough to be sent.
Next: Pickup Patterns
to be continued...
