Analog To Digital Conversion

How does an analog signal transform into a digital audio sample? What equipment is used to turn audio - into a file format that can be stored onto a digital medium?

Digital Audio Conversion

To record and produce music onto CD, with a Digital Audio Workstation: This conversion, and the equipment that facilitates it is an important part of the signal path.

This article is intended to explain these questions, and help you develop a solid understanding for the analog to digital conversion process.

Analog to digital conversion (A/DC) samples the voltage of an audio waveform thousands of times per second. A/D converters process this waveform into streamlined binary numbers. This information is used to represent the voltage of the waveform. These binary numbers are rounded to the nearest value. The process of these calculations is called quantization. Quantizing is used in different functions of the recording and production process. Each binary number, (1’s and 0’s) is called a bit.

In essence, A/D conversion is the process of turning audio samples into its digital replacement, Digital Audio. Digital music is stored onto a digital medium. (Hard-Disk, Mini-Disk, etc.)

Today, it is the most flexible method of recording and storing music. An audio file is a digital format that contains the sound and musical data for a track. A song file holds all the musical information and recording files in a song-project. Audio/song files can be compressed using a number of formats. Compression is used to reduce the size of each song file, making it easier to store.

Mp3 is a popular - compressed file format that you may be familiar with. Reducing the size of audio files inevitably results in a loss of sound quality. The differences in sound quality of compressed/uncompressed formats are subjective to the listener and/or production experience. The obvious advantages of compressed audio files are size, file transfer, and reduced CPU consumption. During music production, audio files are most often left uncompressed. The original audio file - offers more dynamic range and clarity in each track of a musical production.

A/D Converters can be bought as integrated or standalone units. They are commonly built into a number of audio interfaces and digital devices. (I.E. Processors, Preamps, Digital Mixers, etc.) Conversion rates, number of inputs, and build quality all affect the price of A/D Converters.

Music Software and advances in recording technology has blended the warmth/dynamics of analog recording, with digital music’s creative flexibility. The maximum sampling rate and bit depth vary according to each converter. Needless to say, (like all pro audio equipment) A/D converters range in quality and capability.

If you have any questions let me know, and i’ll try to make it more clear by explaining it another way.

Happy Home Recording!

Jamie