Source Independent Measurement Technique; Applications - Meyer Sound MM-4CEU Operating Instructions Manual

CHAPTER 4
The key to MAPP Online Pro's value is the accuracy of its
predictions. Performance predictions for each Meyer Sound
loudspeaker found in MAPP Online Pro are based on a
model of that product built from 360 1/48th-octave–band
measurements taken with a SIM audio analyzer in our
anechoic chamber. The extreme consistency found from
cabinet to cabinet in Meyer Sound products guarantees that
the predictions MAPP Online Pro makes from this high-
resolution data will closely match actual performance.
For touring, MAPP Online Pro allows fast and accurate
planning of system deployment for each venue on the tour,
including both coverage and rigging information. Sound
system designers for fixed installations can inform clients
with understandable graphic illustrations and detailed
statistics on how a proposed system will perform. The
designer then arrives at the installation prepared with a
wealth of information that ensures the system will satisfy
their requirements "out of the box," including basic system
delay and equalization settings. MAPP Online Pro's
accurate, high-resolution predictions eliminate unexpected
coverage problems and minimize onsite adjustments.
MAPP Online Pro client software is upgraded continually in
order to add new Meyer Sound products to the database
and enhance user features. Most upgrades are downloaded
automatically when logging on to a MAPP Online Pro
session. The MAPP Online Pro database includes nearly all
current Meyer Sound products, including all M Series full-
range and subwoofer cabinets.
MAPP Online Pro is compatible with Windows, Linux
Unix , and MacOS (10.4 and higher) operating systems.
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Additional system requirements and recommendations are
listed on the MAPP Online Pro Web page.
SIm 3 mEASUREmENT SySTEm
The SIM 3 audio analyzer system includes a selection of
hardware options, microphones, and accessory cables.
The SIM audio analyzer system is optimized for making
audio frequency measurements of an acoustical system with
a resolution of up to 1/48th of an octave; the high resolution
enables you to apply precise electronic corrections to adjust
system response using frequency and phase (time) domain
information.
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Source Independent measurement Technique

The SIM 3 audio analyzer 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 3 Delay Finder function

Applications

The main application of the SIM 3 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
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by the acoustical environment and the placement
and interaction of the loudspeakers to set corrective
equalization
 Optimizing subwoofer integration
 Optimizing loudspeaker arrays
The 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