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Introductionto  

Signal  Processors  Defined

Method Hardware Software

Analogdirectly  modify  as  signal  passes    through  system  (real-­‐time)

‘built-­‐in’&  external    ONLY     N/A

Digitalconvert to ‘binary’, & modify according to algorithm

‘built-in’, external, & plug-ins

Yes

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Four  Basic  Categories

Processor  Types Examples

1 Spectrum filter,  equalizers,  filter  effects

2 Time delay,  reverb,  etc.  (‘effects’)

3 Amplitude compressor,  limiter,  expander,  gate

4 Noise noise  reduction,  ‘dehisser’,  etc.

SIGNAL FLOW FOR “PROCESSORS”

• ‘insert’  approach

• ‘send/return’  approach

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Equalization

Uses  for  EQ

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Equalizer  v  Filter

�HIGH  PASS:  attenuates  all  frequencies  BELOW a  given  frequency  (passes  “highs”)

Slope  (dB/octave)

Slope  (dB/octave)

�LOW  PASS:  attenuates  all  frequencies  ABOVE  a  given  frequency  (passes  “lows”)

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low  shelf high  shelf

¡ corner   (“turnover” )   frequency :    gain  has  changed  by  3  dB¡ “stop” frequency :  gain   is  no   longer  changing  

• bandwidth:    the  range  affected  on  each  side  of  the  ‘center’ frequency

Peaking  Equalizer

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Graphic  Equalizer

¡most  other  equalizers  have  fixed  frequency  and/or  bandwidth  control

Parametric  Equalizer

■ true  parametric has  a  ‘sweep-­‐able’ or  continuously  variable    frequency,  bandwidth,  and gain  control

■ original  concept  by  George  Massenburg et.  al.