Apple Soundtrack Pro 2 - Manual (Page 340)

340 Chapter 11 Working with Audio Effects
MultiMeter
The MultiMeter combines the functions of the Level Meter and Correlation Meter (as
described above) with several other analysis tools:
 A Spectrum Analyzer
 A Goniometer for judging the phase coherency in the stereo sound field
The control panel to the left of the display allows you to switch between the Analyzer
and Goniometer and contains parameter controls for the MultiMeter. The Stereo Level
and Correlation Meter are always visible.
Spectrum Analyzer
The Spectrum Analyzer divides the audio signal into 31 independent frequency bands.
Each frequency band represents one third of an octave. The filter curves comply to IEC
document 1260.
You turn on the Spectrum Analyzer by clicking the Analyzer button. Turning on the
Spectrum Analyzer turns off the Goniometer. The four buttons below determine what
portion of the input signal the Analyzer is displaying. You can choose between Left or
Right channel only. LR max shows the maximum band levels of either channel, while
Mono displays the levels of the stereo signal summed to mono.
The View options determine the level represented by the top line of the scale in the
display (Top; range: –40 to +20 dB) and the overall dynamic range of the Spectrum
Analyzer (Range; range: 20 to 80 dB). These two parameters can also be set directly in
the display: By dragging directly on the bar graph, you can shift the top line of the
display. Dragging directly on the dB scale allows you to compress or expand the scale’s
range. The View options are useful when analyzing highly compressed material as you
can identify smaller level differences more easily by moving and/or reducing the
display range.
There are three display respond modes: RMS Slow, RMS Fast, and Peak. RMS Slow and
RMS Fast modes show the effective signal average (Root Mean Square) and offer a good
representation of the perceived volume levels. Peak mode shows level peaks accurately.
Goniometer
The Goniometer helps you to determine the coherence of the stereo image. Using the
Goniometer, you can see phase problems as trace cancellations along the center-line
(M=mid/mono). Goniometers developed when early two channel oscilloscopes first
appeared. Users would connect the left and right stereo channels to the X and Y inputs
while rotating the display by 45 degrees, resulting in a useful visualization of the
signal’s stereo phase.
The signal trace slowly fades to black, imitating the glow of the tubes found in older
Goniometers, and at the same time enhancing readability.