User guide

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CHAPTER 5
The Measurements
Figure 5.2. Band Spectrum measurement, All view
5.2. LINE SPECTRUM
5.2.1. Overview
Line Spectrum measurements display the single-channel amplitude response of each of the
measured input channels as absolute rms amplitude dBV (or dBSPL for the mic channel)
versus frequency in Hertz.
5.2.2. Description of the Measurement
The Line Spectrum measurement displays the RMS amplitude of the measured signal at all
frequencies between 8 Hz and 24 kHz. The 1/48 of an octave Line Spectrum measurement is
ideal for verifying signal presence in each measurement channel and the frequency content
of the signal at each point.
Line Spectrum is useful for setting the amplitude threshold for Frequency Response mea-
surements. It is also a useful tool to detect signal roll-offs and other EQ effects at the signal
source, pinpoint feedback, and find and interpret audio phenomena below 80 Hz.The Line
Spectrum measurement is used to measure THD (total harmonic distortion). For more infor-
mation please refer to sections 7.12.1. and 7.12.2.