Specifications

EAW Smaart 6 Operation Manual Analysis Modes and Display Types
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3.2.8 Magnitude Thresholding
Magnitude Thresholding is another way to limit undesirable data from Frequency Re-
sponse measurements by setting a threshold for the reference signal level, below which
incoming measurement signal data is rejected on a frequency-by-frequency basis.
Smaart 6 looks at every frequency data point in the reference signal and if it falls below
the threshold, the corresponding point in the Magnitude trace is not plotted when the
display updates.
There are two benefits to finding the right magnitude threshold, particularly when using
Smaart 6 during a performance or noisy environment:
• It helps keep data off the screen that could not have originated from the system
being measured. We assume that if nothing was put into the system at a given
frequency, nothing should be output at that frequency.
• Since the last valid data point measured should remain on the screen until it is re-
placed by new data, magnitude thresholding prevents the trace from “blowing
up” when a song ends or the stimulus signal stops. This does mean that the trace
may take a few seconds to stabilize when measurement begins. If it does not ap-
pear after a few seconds, reduce the Magnitude Threshold setting until it does.
Magnitude thresholding works intelligently with the trace averaging function to ensure
that only valid new data contribute to the average. When a particular frequency data
point crosses the threshold in one update but not the next, the averaged trace continues
to reflect the last valid value received, so the trace does not immediately disappear at
that frequency.