Dependable, quality information that you can use.
I’m not an engineer, so creating my DVD, “Depression What You Must Know,” and my Podcast, “Psychiatric Secrets Revealed with Dr. Mike” involved a lot a research and learning. The information listed below is a compilation of that work. I hope you find it helpful. Mike Kuna
I have now mentioned microphones several times so I thought I would spend some time exploring this important topic. There are many dozens (if not hundreds) of different microphones. You can spend less than $10 on a microphone or spend many thousands of dollars for one, making choosing confusing. There is also a lot of conflicting information out there, some Podcasters advocate using a simple $29 computer style headset while others emphasize the need for a pro-level microphone like the $799 (retail) Electro Voice RE-20.
Microphones use a number of different technologies to convert audio energy into an electrical signal. Fortunately, there are only three types that Podcasters typically use.
Dynamic Microphones
A dynamic microphone consists of a diaphragm that vibrates when exposed to sound waves. The diaphragm has a tiny coil of wire attached to it. This coil is surrounded by a very strong permanent magnet. When the coil vibrates in the magnetic field a tiny electrical current is generated that electrically corresponds to the sound. Dynamic mics tend to have fairly low output but they are very durable and don’t require any additional power to operate. Because the diaphragm is connected to a coil of wire, it has to be somewhat sturdy which may affect the way that it responds to certain frequencies (especially higher ones). Naturally, sound engineers have found ways around this problem. Because they don’t need external power and they are durable, they are very popular in live performance settings.
Condenser Microphones
Condenser Microphones are sometimes called Capacitor Microphones because this is how they turn sound waves into an electrical signal. In a condenser mic the diaphragm serves as one plate of a capacitor. This capacitor is charged with “Phantom Power.” The Phantom Power (usually +48 volts) is supplied by an external device like a pre-amp or mixer. When the diaphragm vibrates it moves in relation to the other plate and this movement causes changes in the microphone’s electrical signal That signal is then amplified by a tiny preamp in the microphone itself (these mics still need a regular preamp too). Since the diaphragm doesn’t have to support a coil of wire (as in the dynamic microphone) it can be made very large and light weight. Because of this, condenser microphones can reproduce a wide variety of sounds very accurately. Beyond the need for Phantom Power, condensers tend to be delicate. They are super sensitivity which can also be a hindrance as they are excellent at picking up background noise in less than perfect recording environments. In the right setting condensers can be fantastic and they have a higher output than dynamic microphones. Condensers are very popular in controlled settings that require the highest quality sound (like a recording studio).
The Electret (Condenser) Microphone
In 1962 scientists at Bell Labs discovered a way to permanently imprint an electrical charge onto a plate. They used this technology to create a condenser microphone that didn’t need external (Phantom) power. This became the Electret microphone. Although Electrets don’t need +48 volts they do need a small amount of external power, usually a few volts. This powers a tiny preamp that is built directly into the electret’s microphone capsule. That preamp increases the output of the microphone and also adjusts the impedance to a level that is compatible with the connecting recording device. Computer sound cards supply this voltage via the mic jack. Non-computer electrets often use a small battery for this purpose. Output is greater than with a dynamic microphone. More electret microphones are manufactured every year than any other microphone type. Many of these mics can be found in telephones, camcorders, computer-type microphones and other consumer devices. They are popular because they are low in cost, sound good and have a high output. Although most electrets microphones are cheaply made for mass produced products, some high end electrets ones can rival quality studio condenser microphones in sound quality.
So which type of microphone is used for professional sound? All three!
Radio Stations love dynamic microphones like the Shure SM7, The Electro Voice RE-20 or the Sennheiser 421. The Shure SM 58 and SM 57 twins have recorded famous people ranging from Michael Jackson to the President of the United States.
Recording studios tout the excellence of large-diaphragm condensers like the Neumann U87 which costs several thousand dollars. They feel that the silky smooth, balanced sound of the condenser is perfect for them.
Electret technology can be found in lavalieres for video work (Audio-Technica AT831), studio microphones (Shure KSM32) and microphones for live performances (Shure WH30).
Microphones use a number of different technologies to convert audio energy into an electrical signal. Fortunately, there are only three types that Podcasters typically use.
Dynamic Microphones
A dynamic microphone consists of a diaphragm that vibrates when exposed to sound waves. The diaphragm has a tiny coil of wire attached to it. This coil is surrounded by a very strong permanent magnet. When the coil vibrates in the magnetic field a tiny electrical current is generated that electrically corresponds to the sound. Dynamic mics tend to have fairly low output but they are very durable and don’t require any additional power to operate. Because the diaphragm is connected to a coil of wire, it has to be somewhat sturdy which may affect the way that it responds to certain frequencies (especially higher ones). Naturally, sound engineers have found ways around this problem. Because they don’t need external power and they are durable, they are very popular in live performance settings.
Condenser Microphones
Condenser Microphones are sometimes called Capacitor Microphones because this is how they turn sound waves into an electrical signal. In a condenser mic the diaphragm serves as one plate of a capacitor. This capacitor is charged with “Phantom Power.” The Phantom Power (usually +48 volts) is supplied by an external device like a pre-
The Electret (Condenser) Microphone
In 1962 scientists at Bell Labs discovered a way to permanently imprint an electrical charge onto a plate. They used this technology to create a condenser microphone that didn’t need external (Phantom) power. This became the Electret microphone. Although Electrets don’t need +48 volts they do need a small amount of external power, usually a few volts. This powers a tiny preamp that is built directly into the electret’s microphone capsule. That preamp increases the output of the microphone and also adjusts the impedance to a level that is compatible with the connecting recording device. Computer sound cards supply this voltage via the mic jack. Non-
So which type of microphone is used for professional sound? All three!
Radio Stations love dynamic microphones like the Shure SM7, The Electro Voice RE-
Recording studios tout the excellence of large-
Electret technology can be found in lavalieres for video work (Audio-
Microphones