The Audio-Visual Revolution

- a site about the Audio-Visual Revolution.

Title Page
Vinyl
CDs
MP3s
DVDs
Blu Ray DVDs
Bibliography




Web Design by
    Simon Schulz
      (c) 27/5/2005

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  DVDs are a high quality digital recording that allows for high resolution video and surround sound, better than CD quality sound. This is achievable because the data tracks on a DVD are more condensed, and the spacing in between the data cells is smaller, thus a larger amount of raw data is able to be stored. The difference between a CD reader and writer’s laser is the frequency of light. The light from this laser has a smaller wavelength (640 nanometers) than the light from the laser in a CD player (780 nanometers), which allows the DVD laser to focus on the smaller DVD pits. A tracking mechanism that can move the laser assembly so the laser beam can follow the spiral track - The tracking system has to be able to move the laser at micron resolutions.

	CD Audio	DVD Audio
Sampling Rate	44.1 kHz	192 kHz
Samples per second	44,100	192,000
Sampling Accuracy	16-bit	24-bit
Number of Possible Output Levels	65,536	16,777,216

Dvds also come in Audio form which allows for higher quality recording than the audio data on a CD.

The differances in quality between DVD and vinyl is easy to hear. The differance between DVD audio and CD audio is somewhat harder to hear the differance between. This is because the number of samples per second on a CD in comparison to a DVD may be significant, but our ears are not precice enough to be able to determine the differance between the two. Vinyl, on the other hand is a raw signal, so the analogue sound is 'pure', but there is quality loss when the needle of the record player runs over the surface of the record.