balance

balance --  Adjust one audio signal according to the values of another.

Description

The rms power of asig can be interrogated, set, or adjusted to match that of a comparator signal.

Syntax

ar balance asig, acomp [, ihp] [, iskip]

Initialization

ihp (optional) -- half-power point (in Hz) of a special internal low-pass filter. The default value is 10.

iskip (optional, default=0) -- initial disposition of internal data space (see reson). The default value is 0.

Performance

asig -- input audio signal

acomp -- the comparator signal

balance outputs a version of asig, amplitude-modified so that its rms power is equal to that of a comparator signal acomp. Thus a signal that has suffered loss of power (eg., in passing through a filter bank) can be restored by matching it with, for instance, its own source. It should be noted that gain and balance provide amplitude modification only - output signals are not altered in any other respect.

Examples

Here is an example of the balance opcode. It uses the files balance.orc and balance.sco.

Example 1. Example of the balance opcode.

/* balance.orc */
; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Generate a band-limited pulse train.
  asrc buzz 30000, 440, sr/440, 1

  ; Send the source signal through 2 filters.
  a1 reson asrc, 1000, 100       
  a2 reson a1, 3000, 500

  ; Balance the filtered signal with the source.
  afin balance a2, asrc

  out afin
endin
/* balance.orc */
        
/* balance.sco */
; Table #1, a sine wave.
f 1 0 16384 10 1

; Play Instrument #1 for two seconds.
i 1 0 2
e
/* balance.sco */
        

See Also

gain, rms