What do we mean by digital audio? As you probably know, sound travels through the air as minute, rapid variations in pressure which describe the pitch and loudness of the sound. If you were able to see them as they pas through a single point you would see a continuously changing wave. Digital audio is a method of representing the waveforms as a series of discrete numbers. To do this the digital audio recorder takes "snapshots" of the sounds called "samples" to represent the waveforms. When these snapshots are played back at a certain speed we hear a continuous sound. The process is a more complex version of how movies work essentially.

There are numerous storage media for digital audio. The most common is the compact disc. CD recorders are usually used as mixdown machines to record the final product. They come in stand alone recorders and as CD burners for your computer. The next most common form of media is digital audio tape or DAT. These are usually used to record the raw audio to be mixed latter on. There are also multitrack DAT that can record more than just two tracks of digital audio. The last of the external media used to record audio is the mini disc. These are small discs that can record 74-80 minutes of digital audio. Because of their small size the audio is compressed which makes the quality not as good as CDs or DATs, but the difference is usually not noticeable on most situations. If fact, mini discs have been used to record audio to be released on commercial CDs and have been used in a number of professional situations. Finally, you may record digital audio on a computer. As computers are becoming faster and more powerful this becoming the standard for recording studios around the world and is making home studios far more affordable.

Microphones are the beginning of the recording chain and an important element to quality recordings. The job of a microphone is to translate the moving air waves and pressure created by sound into fluctuating electronic signal levels used by electronic equipment. On the opposite end of the chain is the speaker, which translates the electronic signals back into the moving air waves and pressures that we call sounds.

Types of Microphones Most of the microphones that you will encounter will be of two types: dynamic and condenser microphones. Dynamic microphones are probably the most common type of microphones that you will find. They are dependable, rugged, and are simple to use. You will find that they are widely used in both the studio and in live performance. These are usually the most inexpensive microphones, but beware that they are all not created equal. Condenser microphones on the other hand can be some of the finest microphones available, but they can be quite expensive. These microphones translate sound waves into electrical signals differently than dynamic microphones. Unlike the dynamic microphone the condenser microphone requires a power source to run. The power is drawn from either a battery inside the microphone or by phantom power (a source of power from an external source delivered through the microphone line usually from the mixer).  Response Patterns The way that a microphone picks up sounds is called a response pattern. The polar response refers to the physical positions of sound that the microphone will pick up. In the diagram to the right you will find a number of response pattern that you could encounter. The frequency pattern refers to the microphone sensitivity to various pitches. In other words the range of frequencies that the microphone could pick up.

Next in the recording chain is usually a mixer. The most elementary function of a mixer is taking two or more audio signals and combining them, but a mixer could become the center of recording activities. You can use a mixer to set recording and monitor levels, etc. The list is almost endless. Usually when a person first looks at a typical mixer, such as the one pictured to left, for the first time can be a daunting task . But a typical mixer is laid out in such a way that it can become easy to use. The mixer is divided into channel strips with each channel with its own set of controls. So, if you know how to operate one channel strip you can run them all.

To the left is a typical channel strip for a channel with a microphone input. The first knob that you see under the inputs (in this case mic an line levels) is the trim. This allows the signal entering this channel to be adjusted to the optimal level before entering the rest of the channel path. The settings of the trim may vary from mixer to mixer so be sure to look up how the trim works for your particular mixer in its manual. Below the trim are the auxiliary sends. These knobs will tell the mixer how much of the signal to send to outboard equipment such as compressors, reverb units or gates. Next in the signal path is the EQ. The EQ allows you to boost or cut the signal at various frequency ranges. This adjust the sound of the signal but be careful, overusing the EQ can really make a mess of your sound. Under the EQ is the pan pot. This allows you to adjust the amount of signal sent to the left or right outputs. The two buttons underneath the pan pot are the Mute and Solo buttons. These allow you stop the signal from continuing through the signal path (mute) or allow only that signal to continue and mute the other channels (solo). Finally the last knob you see at the bottom of the channel is the Gain. This knob can also be a fader (common on many mixers). The gain controls the final level of a signal.