The Analog to Digital conversion process

Hello! My name is Marcos Cirino, and I am from Puerto Rico. I currently play in an alternate rock-band called 23rd Street. I am taking this class to further my knowledge of the music creation process. Here I will talk about the analog to digital conversion process.

The device responsible for changing an analog signal into a series of numbers is the analog-to-digital converter (or A/D converter). It samples the strength of the changing voltage at regular intervals, generating a steady stream of numbers. Two parameters directly affect the quality of the resulting audio: sample rate and bit depth.

The converter's sample rate dictates how often it measures the signal to generate a new value. The more frequently the converter measures the signal, the more accurate the resulting data. Sample rate corresponds directly to frequency response; the highest frequency a digital system will capture is exactly one-half the sample rate. To capture the full audio spectrum up to around 20,000 cycles (or 20kHz), a sample rate of 44.1kHz is common. Higher sample rates make for increased treble response and a more "hi-fi" sound. Low sample rates sound duller and darker.

Bit depth affects how many bits the converter uses for each numerical measurement of the signal. More bits equal a more accurate measurement, which explains why 16-bit CD audio sounds so much better than an 8-bit multimedia sound file. A low bit depth is like forcing the converter to measure the sound with a yardstick marked only in inches. A higher bit depth allows the converter much greater accuracy (a yardstick marked in 1/8th-inch increments, for example).

Thank you for reading, and I look forward to your feedback!

Sources: 

http://www.videomaker.com/article/3258-audio-advice-analog-to-digital-conversion