• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

How audio products work.

Extracts from this document...


Katie Sheppard GNVQ Media Audio unit 5 How audio products work. There are several standard music distribution formats. The MP3 and the compact disc (CD) are the two most common at the moment, but cassette tapes are still around. The Sony Minidisk is another format that Sony has been trying to popularize for many years. A Minidisk looks a lot like a floppy disk but is slightly smaller (7 cm, 2.75 inches square). CDs store 74 minutes of music in a nearly indestructible form and have the advantage of being a digital format, but until fairly recently you could not record on a CD. The Minidisk's main claim to fame is that it is (and always has been) recordable. One easy way to think about a Minidisk is like a floppy disk -- you can record and erase files on a Minidisk just as easily as you can on a floppy disk. The big difference between the a Minidisk and a floppy disk is that a Minidisk can hold about 100 times more data. Minidisks come in two forms: 1 Pre-recorded 2 Blank and recordable A pre-recorded Minidisk is exactly like a CD, except smaller. ...read more.


The difference in height between the two places is exactly a quarter of a wavelength of the laser beam light, so the original beam is totally eliminated by the interference between the beam reflected from the surface of the disc and the beam reflected from the ridge. The photocell does not produce current. It should be noted that the ends of the ridges seen by the laser are "ones" and all lands and ridges are "zeros"; thus turning on and off the reflection is one, steady state is a string of zeroes. As it is not possible to have two ones next to each other, Eight to Fourteen Modulation (EFM) is used to convert 8-bit data bytes to 14 bit units that always have a minimum of 2 and a maximum of 10 zeros between ones. This makes the pits/ridges and lands separating them 3 to 11 bits long, no less, no more. This conversion is done in hardware using a ROM lookup table. To connect these 14 bit units 3 merge bits are used to make sure that there are no "ones" too close to each other. ...read more.


CDs should be cleaned radially: not along the grooves, but at right angles to the direction of the grooves. If a smear, however small, should remain on the CD, running along the direction of the grooves, much information would be lost. It is advisable to use special CD cleaner that operates with a rotating brush at right angles to the direction of the grooves. Many people think that the digital CD is produced completely digitally, but this is not always the case. Many CDs have an analogue master tape as their source tapes still kept in the library of the record company, used in the past to make records. The quality of a CD made from analogue tape can be surprisingly high. A CD recorded, processed and dubbed digitally does not always sound better than a CD produced with one or two analogue processing stages. To indicate what stages have been treated in what ways, a useful three-letter code is used on recordings. The letters represent: the recording, the editing/mixing process, and dubbing, respectively. They are printed on the CD and/or on the insert label in a rectangular box. There are three possibilities: DDD (completely digital CD); ADD (analogue recording, digital processing and dubbing); and AAD (analogue recording and processing, digital dubbing). Many CDs carry the ADD or AAD indication. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Computer Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Computer Science essays

  1. ICT Sample Work Welcome Centre Requirements

    of Delegates BOOKING DETAILS: Room names, Qty Required, Unit Cost, Subtotal Equipment, Qty Required, Unit Cost, Subtotal Beverages, No. of Delegates, Price per Delegate, Subtotal Food Option, No. of Delegates, Price per Delegate, Subtotal TOTALS: Net Total, VAT Amount, Gross Total STORAGE REQUIREMENTS The following Data needs to be stored

  2. Smart Card System

    Prototyping 7.1 Introduction System design is a general overview of system covering a number of design methods and containing good general advice about design and the design process. Design specification is introduced to the design process, system design strategies and the specific problems of real time systems and user interface design.

  1. With diagrams compare and contrast the relative advantages and disadvantages of digital transmission over ...

    Signals also have a property called wavelength, which is inversely proportional to the frequency. 2) In some information technology contexts, a signal are simply "that which is sent or received," thus including both the carrier and the data together. 3)

  2. System I designed in order to produce a promotion package for her newly formed ...

    I received feedback from my family, friends and relatives. I later typed the data up in Microsoft Access. The table is shown below: Customer ID Last Name First Name Gender Birthdate Place of Birth 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

  1. Propose to research the WTLS or Wireless transport layer security protocol along with the ...

    had to be picked that was sufficiently large but also had to remain constant in order for the data to be easily analyzed. I decided that testing 1,000,000 starting points would be sufficient and give enough data to analyze. Looking at it from an outside view, 1,000,000 starting points would

  2. ICT Sample Work India Red

    going in and profit coming in and Ahmed's main duty is to sort out staff's wages. John Thompson is the reception worker, who takes order therefore he will fill in the order form once created.They also have three chefs who will only look at the orders.

  1. Analysis of Johnson Music

    * Human error can be a problem, with staff possibly forgetting to change the stock levels of products being sold, or possibly forgetting to order more of a certain product in when it has been sold out * Searching through paperwork can result in papers being misplaced, and can be

  2. The seven layer osi model

    In many cases the 6th layer is skipped by the protocol stack implementation and communication goes directly between application and session. Session The session layer of the seven layer model is where the first basis of communication happens. Session is considered a form of management utility and makes sure that

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work