Sound REINFORCEMENT SYSTEM

							SOUND
 REINFORCEMENT
 SYSTEM
                       BASIC CONCEPT
•  A sound reinforcement system is the
  combination of microphones, signal
  processors, amplifiers, and loudspeakers
  that makes live or pre recorded sounds
  louder and may also distribute those
  sounds to a larger or more distant
  audience.
• It is the system to amplify the sound at
  large scale or small scale areas.
• The system may be complex as it
  includes hundreds of microphones,
  complex mixing, thousands of watts of
  amplification, and multiple
  loudspeakers for larger spaces, whereas
  it can be simple for small space
  consisting of single microphones
  connected to loudspeaker system.
                        WHAT IS NEED?
• The system is generally needed if room volumes exceeded 60000cu.ft.
  The voice could not reach properly after a particular distance. As the
  distance increases the sound level decreases.
 For ex.

  source                                                    listener


           2ft.
 Now,                            128 ft.
          by inverse square law, doubling the distance will drop the sound
 intensity ¼ i.e. 6 db. So we could calculate how much voice will reach to
 listener.    80db                           2ft
            74db                           4ft
            68db                           8ft
            62db                           16ft
            56db                           32ft
            50db                           64ft
            44db                           128 ft
      REINFORCEMENT COMPONENTS
Basically three components are used-
• MICROPHONES
• AMPLIFIERS
• LOUDSPEAKERS
MICROPHONES: It is (also called mic) an acoustical input electric
   transducer that convert sound into an electrical signal. It is provided at
   the source. There are 5 types of microphones as-
a)Carbon, b)dynamic, c) ribbon, d) condenser, e)crystal




   carbon                dynamic



                                              ribbon             crystal
AMPLIFIERS: It is used to
  amplify the sound signal
  from source to listener.
  Some amplifiers are-
a) mixers, b)equalizers, c)
   compressors, etc.


LOUDSPEAKERS: these are
    provided at different spaces
    and levels for transmitting
    sound to listener. It is
    categorized as-
a) Subwoofers b) compressor
    dividers, c)tweeters
                   TYPES OF SYSTEMS
There are two systems as:
• Central system- it is most preferable type in which a loudspeaker is
  located directly above the actual source of sound. Only one loudspeaker
  is used and it is capable of giving maximum realism.
The loudspeaker consists of cluster of directional horns.
DISTRIBUTED SYSTEM: In this system, one uses a large number of
   loudspeakers distributed uniformly over the audience area. With
   loudspeakers located over the audience , system acts like down lighting.
• Each listener receives sound from only the closest loudspeakers.
• It is the logical system for airport terminal buildings.
• If ceiling height is not so much then loudspeakers can be attached to
   backs of seats in conference rooms, mounted in desks in legislative
   rooms.
                  POOR
                  DISTRIBUTION
                  SYSTEM




LOUDSPEAKERS AT
BOTH SIDES
CREATE POOR
DISTRIBUTION IN
THE ROOM