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There are so many different kinds of external microphones, it’s easy to get confused about which to choose for what kind of use.

This article covers the different types of [tag-tec]microphones[/tag-tec] for home recording, with a summary of how each works, and where best to use them.

Before we go on, here’s a couple of important tips:

Connectors Confusion

Some can plug directly into the computer’s input jack – probably a 1/8th inch jack socket. However microphones come with different types of connectors. For example, you’d need an adapter to accommodate the XLR (three prong) connector – standard with balanced cables – into a 1/8th inch jack.

Adapter Quality

The quality of the adapter matters. With a higher quality adapter, there will be lower loss in signal level. So audio quality is more easily maintained as the audio signal is converted into digital format for the computer.

Dynamic

Dynamic mics use moving coil technology – a thin plastic diaphragm that is attached to a coil of wires, surrounded by a magnet. When the air flow hits the diaphragm it vibrates which causes the coil to vibrate. Anyone with elementary physics knows that moving a wire in a magnetic field causes an electric current to flow in the wire. And so the air vibration is transformed into an audio signal.

Dynamic microphones are known to be robust and can handle high levels of sound. They have a relatively high sensitivity but it takes quite a lot of air flow to get the coil of wires vibrating. Therefore, quieter sounds are not picked up as clearly as with a condenser microphone.

Condenser

The most common type of microphone used today for home recording. It is created using a different technology – a combination of a conducting diaphragm, separated from a fixed back plate by a very thin insulating layer. A dc power source is used to create a static electric charge across the diaphragm and back plate, and so the device acts as an electrical capacitor or “condenser”.

When sound waves hit the diaphragm, it vibrates. These minute vibrations compress the insulation layer, thereby varying the capacity of the device to hold electric charge, and a minute electric current is generated. So the air waves are converted to mechanical vibrations, and subsequently to an electrical audio signal as the electric charge varies in synch.

What is the power source that provides the static charge? There are three sources of power:

• A battery
• A permanent charge place on the back plate or on the diaphragm
• Phantom power: ground cables either from a mixer, a phantom power box or a battery pack

Because of their lighter construction (no heavy magnet), condenser mics are generally more sensitive than dynamic mics. Microphone designers believe that the lighter and smaller a diaphragm is, the more accurate the sound will be. There have been a lot of developments in the area of condenser microphones especially with the growing popularity of home recording.

An important attribute to consider is their ability to accurately capture sound as it truly is. Therefore, if something does not sound good you will know – before its too late!

Ribbon

Generally, ribbon mics are only used in top recording studios – mainly because they are extremely sensitive, and they can be damaged easily.

They work on the same principle as dynamic microphones, but are constructed differently -using a ribbon of metallic foil positioned in front of a magnet. The foil acts as the diaphragm, and vibrates when hit by the sound waves. This results in the electric current fluctuation that transmits the audio signal.

Ribbon microphones were used more widely before condenser microphones became sensitive enough for studio use. Now Ribbon microphones are used mostly for specialty work.

Pick up Patterns

The sound pick up pattern is important. Understanding what your needs are for recording is vital to knowing what kind of pick up patterns your microphone needs to have, if any particular one at all.

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Tricks and Techniques

As with most technical equipment there can be a lot of factors that makes it successful. Listed below are a few tips and techniques to help you get the best from your microphone.

Matching the right microphone sound with the right instrument or vocalist is an art as each microphone has its own individual qualities.

Proximity – How close?

Depending on what you are trying to accomplish, it can be very important how close the microphone is to the sound source. For example, to effectively eliminate outside background noise, it is best to have the microphone close – one to three inches away. Anything further than that is considered distant placement. Distant placement is used mostly when you are trying to pick up a larger group of instruments.

Separation - How to prevent sound leakage

If you are recording more then one instrument at a time it is important to separate instruments or block them from each other to prevent sound leakage. One solution is to use an acoustic barrier which can be anything that separates and absorbs individual sounds.

Recording with headphones is essential because it allows you to hear what is recording through the microphone in real time. With headphones you also have the ability to hear the click track while recording to help match the tempo of what has already been recorded.

Use a nylon screen to protect the microphone and reduce sensitivity to feedback. You need to put the screen between the instrument or musician and the microphone.

How to Buy

For a given budget, there are two options when deciding what microphone to buy for your home studio. Do you invest in a single high quality microphone or do you purchase several less expensive ones? The answer to this question for you depends on what your recording needs are – how many simultaneous sound sources, and how diverse they are.

Recording with microphones is largely a matter of trial and error. Each microphone has individual qualities as does every instrument and musician. Finding the right combination of performer, microphone, and placement can be a challenge, but this is where the your recording genius is born.

Filed under: Microphone Basics on July 2nd, 2007