Digital Recording & DAT
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This paper will discuss the concept of digital recording, with a focus on digital audio tape (DAT) recorders. The methods of digital recording sharply contrast those of analog recording which preceded them. Analog recording is based on the concept of capturing the shapes of sound waves as they vibrate in the air. In an analog recording, sound is "stored as a physical representation of the original soundform" (Brewer and Key 18). An example of this can be seen in the squiggly lines which form the grooves on a phonograph record. With digital recording, on the other hand, computer technology is used to convert analog waveforms into numerical, or digital, data (18). In a compact disc (CD) player, this data is read by means of a laser; in a DAT player, it is read by means of a rotary tape head. Because digital recording uses numerical data instead of physical waveforms, there is a great deal of reduction in terms of extraneous noise. Analog recordings tend to be noisier because they pick up all sound signals without discrimination. For example, an analog recording may confuse a scratch or a glitch as being part of the music. By contrast, digital recording "is just a computerized sequence of numbers, so the medium's defects can't be mistaken for those of the original" (Berger and Fantel 102-103). The concept of digital recording did not become fashionable until the 1970s. By contrast, analog recording techniques date back to the late nineteenth century and the pioneer
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T (Sweeney 151). In order to copy a CD onto a DAT, the digital signal must be changed to analog and then back again. This results in a reduced quality of sound when compared to digitally manufactured tapes or CDs. The reasoning behind this innovation is related to the recording industry's concern over potential lost revenues caused by DAT marketing. Thus, "industry leaders want taped copies to be inferior to compact discs to reduce the incentive for duplicating commercial releases" (151).
The high quality of digitally recorded tapes depends a great deal on the use of filtering systems. For example, one important filter, known as an anti-aliasing filter, cuts out all frequencies which are above the range of 20 kilohertz. Because the sampling rate in digital recording uses 20 kilohertz as its peak, problems arise if frequencies above that level are permitted to enter into the system. Specifically, signals whose frequencies are too high become confused with lower ones. This results in the creation of unwanted tones, known as "aliases." An anti-aliasing filter is "an electronic circuit that removes extraneous, high-frequency tones from an input signal" (Brewer and Key 171). Often, filters such as this are digital, because
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Some common words found in the essay are:
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Approximate Word count = 4006
Approximate Pages = 16 (250 words per page)
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