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IQ–P.I.P.–SLM Programmable Input Processor with Load Monitoring for IQ Systems
Reference Manual
Note:
While the frequency ranges of the tests for
each channel will be restricted to those set by indi-
vidual start/stop parameters, the sweep itself will
begin at the lower of the two Start frequencies and
end at the higher of the two Stop frequencies. The
sweep becomes active/audible only over the fre-
quency range defined for each channel.
Generator Amplitude:
This controls the level of the
sweep for the respective channel (channel 1 or 2).
Its range is –40 dBu to +10 dBu. Note that the gen-
erator amplitude is also used to control the level of
output for the Fixed Frequency Generator.
Sweep Resolution:
Sets the frequency step size of
the test sweep. It can be set to 1/24-, 1/12-, 1/6-,
1/3-, 1/2-, 2/3- and 1-octave steps. Both channels of
the PIP-SLM share the same Sweep Resolution.
When both the audio system and the signal generator
have been properly configured, tests should be per-
formed to establish the “baseline” results for normal
operating conditions. Reference test results will be
stored as voltage, impedance, or voltage and imped-
ance curves in local memory; one curve per channel.
In addition, the most recent test results may also be
retained in local memory: one curve per channel of
voltage, impedance, or voltage and impedance. User-
defined labels for all curves may also be created and
stored in local memory. Please consult the documen-
tation for your IQ software for instructions on initiating,
monitoring, and aborting tests, as well as viewing test
results.
3.19 Fixed Frequency Generator
When a test is not being conducted, the signal gen-
erator can be used to produce a steady sine wave sig-
nal (test tone) at a fixed frequency for other
applications.
Caution: Use care when operating the test oscilla-
tor manually.
The oscillator is capable of supplying
high-level sine waves to the amplifier, which will, in turn,
supply them to the load. A poorly adjusted oscillator
could easily damage loudspeakers or other sensitive
components. Remember, Crown is not liable for dam-
age due to the overpowering of other components.
The signal generator is configured using the
IQ Sys-
tem and IQ for Windows 1.1 software to set the follow-
ing parameters:
Fixed Frequency Generator On/Off:
When turned
on, the generator will output a fixed sine wave to that
channel at the frequency specified by the Fixed Fre-
quency Generator Frequency Setting.
Fixed Frequency Generator Frequency Setting:
This determines the frequency setting for the fixed
sinewave generator. It can be set from 20 to 22,000
Hz.
3.20 Test Tolerances
Once the audio system’s baseline results for normal
operating conditions has been established, tolerances
should be set to define an acceptable “window” of op-
erating conditions. Two tolerance settings are available
for configuration: Impedance and Frequency. Consult
your IQ software documentation for information on us-
ing the software interface to set tolerance amounts.
Impedance tolerance:
This sets the percentage of
difference by which an impedance test may vary
from the reference and still be considered “passing.”
Tests conducted where the impedance is measured
at a percentage outside this tolerance at any point
along the frequency range will be considered “failed”
for purposes of the impedance test.
Frequency tolerance:
This sets the difference in dB
by which a frequency test may vary from the refer-
ence and still be considered "passing." Tests con-
ducted where the frequency is measured at a dB
level outside of this tolerance at any point along the
frequency range will be considered "failed" for pur-
poses of the frequency test.
3.21 Dataframe Trigger
(
IQ for Windows 1.1 software only) This software op-
tion configures the
IQ System so that any subsequent
loading of the specified dataframe will result in the ini-
tiation of a test.
3.22 Synchronous Operation (Sync Mode)
When used in conjunction with an
IQ–SLM-8, multiple IQ–
P.I.P.–SLMs can be configured for synchronous operation
using the shared
IQ–SLM-8 test signal. When this option
is specified via IQ software, data gathering will take as
long as the longest possible sweep as required by
eight channels of data gathering in the Crown SLM-8.
When set in this configuration, a single
IQ–SLM-8 gen-
erator may be used to provide the source signal for all
units under test. To use this feature to its best advan-
tage, all Start/Stop frequencies and the Sweep Resolu-
tions must be set the same for all units under test. Also,
the start of the test must be synchronized either by us-
ing the "All Start" option or by using remote Aux In trig-
ger.