Chapter 5: Sim® System; Sim Measurement System; Source Independent Measurement Technique; Applications - Meyer Sound MILO Operating Instructions Manual

CHAPTER 5:
SIM® SYSTEM

SIM MEASUREMENT SYSTEM

SIM is a measurement and instrumentation system
including a selection of hardware and software options,
microphones and accessory cables. SIM is optimized for
making audio frequency measurements of an acoustical
system with a resolution of up to 1/24th 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

SIM implements the Meyer Sound 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

Applications

The main application of SIM 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
SIM 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
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