Sim Measurement System; Source Independent Measurement Technique; Applications - Meyer Sound M SERIES Operating Instructions Manual

CHAPTER 5

SIM MEASUREMENT SYSTEM

The SIM audio analyzer is a measurement and
instrumentation system including a selection of hardware
and software options, microphones and accessory cables.
The SIM analyzer is optimized for making audio frequency
measurements of an acoustical system with a resolution
of up to 1/24 of an octave; the high resolution enables you
to apply precise electronic corrections to adjust system
response using frequency and phase (time) domain
information.

Source Independent Measurement Technique

The SIM audio analyzer implements Meyer Sound's source
independent measurement technique, a dual-channel
method that accommodates statistically unpredictable
excitation signals. Any excitation signal that encompasses
the frequency range of interest (even intermittently) may
be used to obtain highly accurate measurements of
acoustical or electronic systems. For example, concert halls
and loudspeaker systems may be characterized during a
musical performance using the program as the test signal,
allowing you to:
 View measurement data as amplitude versus time
(impulse response) or amplitude and phase versus
frequency (frequency response)
 Utilize a single-channel spectrum mode
 View frequency domain data with a logarithmic
frequency axis
 Determine and internally compensate for propagation
delays using SIM Delay Finder function
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Applications

The main application of the SIM audio analyzer is
loudspeaker system testing and alignment. This includes:
 Measuring propagation delay between the subsystems
to set correct polarities and set very precise delay times
 Measuring variations in frequency response caused
by the acoustical environment and the placement
and interaction of the loudspeakers to set corrective
equalization
 Optimizing subwoofer integration
Optimizing loudspeaker arrays

The SIM audio analyzer can also be used in the following
applications:
 Microphone calibration and equalization
 Architectural acoustics
 Transducer evaluation and correction
 Echo detection and analysis
 Vibration analysis
 Underwater acoustics