Specifications

EAW Smaart 6 Operation Manual Analysis Modes and Display Types
42
Averaging
Averaging is used in RTA, Spectrograph, and Frequency Response measurements to
increase the effective signal-to-noise ratio (S/N) of the measurement and reduce the
influence of transient events. This stabilizes the display and makes overall trends easier
to see. Spectrum measurements use RMS averaging but several integration schemes are
available: linear first in, first out (FIFO), Infinite, Fast, Slow, and Exponential.
FIFO averaging is a simple arithmetic average of the 2
n
(n = 0, 1, 2...7) most recent FFT
frames with equal weight given to each. Note that when the number of averages is set
to 1, averaging is not performed; each display update includes only the magnitude data
from the most recent FFT frame.
Infinite (Inf) averaging is similar to FIFO in that every FFT measurement in the average
is given equal weight but rather than looking at a fixed number of the most recent FFT
frames, this option keeps a running of average of all FFTs recorded since the last time
the buffer was flushed. Averaging buffers are flushed (re-seeded) when changes are
made to averaging parameters, FFT size, or sampling rate, starting the analyzer,
switching between display types, and pressing the V key.
Figure 3-6 Average options (left); Weight options (right)
Weighting Curves
The Weight setting in the Spectrum display control section applies a frequency-dependent
weighting curve to the RTA, Spectrograph displays. Some common weighting curve types
are shipped with the program (right of Figure 3-6), including ANSI/IEC A and C types
and X curves for cinema systems. Additional curves may be added to this list by adding
files to the Weighting folder. The Spectrum section’s Weight control applies only to
the RTA and Spectrograph displays. Spectrum and Freq. Response (Magnitude only)
displays can be weighted independently. See Weighting Curves on page 65.