Reference Manual

355 Live Audio Effect Reference
(Note: the Spectrum device is not available in the Intro and Lite Editions.)
Spectrum performs realtime frequency analysis of incoming audio signals. The results are repre-
sented in a graph, with dB along the vertical axis and frequency/pitch along the horizontal. The
peak levels are retained on the graph until the song is restarted. Note that Spectrum is not an
audio effect, but rather a measurement tool — it does not alter the incoming signal in any way.
The Block chooser selects the number of samples that will be analyzed in each measurement.
Higher values result in better accuracy, but at the expense of increased CPU load.
Channel determines which channel is analyzed — left, right or both.
The Refresh slider determines how often Spectrum should perform an analysis. As with the Block
parameter, this allows for a tradeoff between accuracy and CPU load. A fast response time is
more accurate, but also more CPU intensive.
The Avg slider allows you to specify how many blocks of samples will be averaged for each up-
date of the display. With a setting of one, each block is shown. This results in much more activity
in the display, which can be useful for finding the spectrum of short peaks. As you increase the
Avg value, the display updates more smoothly, providing an average of the spectrum over time.
This is more consistent with the way we actually hear.
The Graph button switches between displaying the spectrum as a single interpolated line and
discrete frequency bins.
Max toggles the display of the accumulated maximum amplitude. With Max enabled, you can
reset the maximum amplitude by clicking in the display.
The Scale X buttons allow you to toggle the scaling of the frequency display between linear,
logarithmic, and semitone. Note that logarithmic and semitone are actually the same scaling,
but switch the legending at the top of the display between Hertz and note names. Linear scaling
is particularly useful for detailed analysis of high frequencies.
As you move your mouse over Spectrum’s display, a box appears that shows the amplitude,
frequency and note name at the pointer’s position. The Range/Auto button at the bottom left
of Spectrum’s interface toggles between manually and automatically adjusting the display’s
dynamic range. With Range selected, you can zoom and scroll the amplitude by moving your
mouse over the amplitude legending on the display’s left side. Drag vertically to scroll and hori-
zontally to zoom. You can also use the Range sliders to set the minimum and maximum amplitude
values shown. With Auto selected, the display automatically scales itself based on the incoming
audio level. Note that in Auto mode, the Range sliders and zooming are disabled.