Preparing The Equipment - Larson Davis SoundAdvisor 831C Reference Manual

18
Module 18
T
determine the frequency content and tonality of the measured sound.
In FFT Mode, the 831C captures the waveforms of even complex sounds, computes the time
and frequency domains, extracts peak frequencies and amplitudes, and applies chosen
digital filters and data windowing preferences to produce the resulting data for view on the
meter and in G4 LD Utility.
The 831C is also the instrument of choice for making an FFT measurement to assess the
audibility of tones in the measured sound, according to international standards (ISO 1996-
2, ISO PAS 20065).
This module provides an example procedure, which shows how to operate the
SoundAdvisor™ 831C to make an FFT and Tonality measurement and analyze the resulting
data on the meter. This process requires the SoundAdvisor 831C with firmware version 4.6
or newer, and the 831C FFT and Tonality option (831C-FFT) installed. All options and
accessories shown here are available from Larson Davis.
Overview:

18.1 Preparing the Equipment .................................................................................................. 137

18.1.1 Preparing the Mic
18.1.2 Preparing Other Transducers
18.2 Creating an FFT Setup File On the Meter ........................................................................... 139
18.3 Making the FFT Measurement ............................................................................................ 145
18.3.1 Viewing Live Data On the Meter
18.4 Viewing FFT Data Files On the Meter ................................................................................. 151
18.1 Preparing the Equipment
Choose the section below that applies to your transducer to prepare and calibrate for a
measurement. While you may use any transducer, this example shows how to select
settings for a mic or an accelerometer. Selectable options for other transducers closely
resemble one or the other of these.
You may also complete this process by using G4 LD Utility or the LD Atlas app for mobile.
In this section:
SoundAdvisor Model 831C
FFT & Tonality Measurement
he SoundAdvisor™ 831C and the FFT and Tonality firmware option are used to
18.1.1 Preparing the Mic
•
18.1.2 Preparing Other Transducers
•
Preparing the Equipment 137