Crown I-Tech I-T4000, Operation Manual

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I-Tech Series Power Amplifiers
Operation Manual page 29
4.6 Software-Controllable Onboard DSP
Crown’s latest-generation Digital Signal Processing is built into the
I-Tech amplifier. Its 24-bit/96kHz converters offer extremely low noise
and extended dynamic range. When you use an I-Tech amp, the loud-
speaker processors, crossovers, limiters and delays are in the onboard
DSP – so you don’t need those rack-mounted devices. This drastically
cuts setup time, commissioning, rack space and costs.
The I-Tech’s DSP can be monitored and controlled with a computer
running IQwic software, and connected to the amplifier Network Con-
nector by a network Category 5 cable.
Some applications for this DSP are:
• Set up signal flow
• Optimize system gain structure
• Set up speaker configurations (set the drive levels, frequency bands,
delays and limiting for your particular speakers)
• Set up EQ, filtering, compression, and much more.
Listed below are the available DSP functions.
4.6.1 User Presets
The control settings for all the functions can be stored as presets.Up to
20 presets can be saved in the I-Tech amp’s nonvolatile memory. Each
preset can be named with a 30 character name describing its function,
which is also stored in memory.
• The Store Preset Control saves the current setting to the specified
preset.
• The Recall Preset Control recalls the specified preset settings.
• The Preset Valid Monitor indicates if a change has been made to
any setting since the last time a preset has be saved or recalled.
• The Last Stored or Recalled Preset Monitor indicates what the
Last Stored or Recalled preset is.
4.6.2 Clip Event Monitor
A clip detector is provided each channel. These monitors will indicate
any clip condition (> 0.05% distortion) in the amplifier channel. The
clip detectors also can indicate Thermal Level Control limiting or
incorrect setting of Stereo/Bridge-mono mode in the LCD-screen
menu.
4.6.3 Input Signal Level Monitor
The input signal level of each channel can be monitored. The measure-
ment range is from +20dBu to –40dBu with 0.5dBu resolution. Each
audio channel has the following monitors:
• Analog Audio Input: The audio input at the Balanced Audio Inputs
of the I-Tech amplifier.
• Switched Audio Input: The audio input after the Input Audio
Router.
4.6.4 Output Signal Level Monitor
The output signal level of each channel can be monitored. The mea-
surement range is from 0 dB to –40 dB with 0.5 dB resolution. The
monitors are scaled so that 0 dB is referenced to the full rated output
voltage of the amplifier.
4.6.5 Thermal Headroom Level Monitor
The thermal headroom level of each channel can be monitored with the
software. This level represents the percent of available power/thermal
capacity that is currently being used within the output section of the
amplifier. When the thermal headroom level reaches 100%, the ampli-
fier cannot produce any more power and it will begin to protect the
output devices by limiting their drive level. The thermal limiter feature
of the I-Tech’s DSP can be set to engage at a pre-selected thermal
level.
4.6.6 Power/ Standby Control
Each channel can be independently turned on and off.
4.6.7 Signal Mute
The output signal of each channel can be independently muted. This
function produces 60 dB or more of attenuation.
4.6.8 Polarity Inverter
The input signal polarity of each channel can be independently
inverted.
4.6.9 Dynamic Gain Monitors (Ghost Faders)
These indicators let the user monitor the actual signal path gain. The
actual gain may vary from the input attenuator settings as a result of
compression and limiting. On standard IQwic software control panels,
these indicators appear as flying ghost faders behind the input attenu-
ator controls.
4.6.10 Amplifier Information
Information about the amplifier is stored in the IQwic software system
inventory and is displayed on the software control panels. Information
includes manufacturer, model, date code, and serial number.
4.6.11 User and Channel Labels
The I-Tech amplifier can store two user labels and two channel labels.
These labels are 30-character strings that can be set by the user to
indicate the function of the amplifier and its channels. For example,
“LOWER RIGHT CLUSTER, FOR DELAY.”
4.6.12 Line Voltage Monitor
The AC line voltage supplied to the amplifier can be displayed with this
function. No user input is required.
4.6.13 Error Reporting
The I-Tech amplifier can detect four different error conditions per
channel and errors in the AC line voltage. Each error type can be indi-
vidually configured to report the error through the network and/or the
AUX port. Network reported errors appear in the IQ System
®
Error
Window. The IQwic software offers many options to further report
errors, including audible alerts, printout, email, pager, serial port and
fax. The following describes each error source.
CLIP: The I-Tech can be configured to report if an excessive number
of clip events occur in either amplifier channel. The clip events are
consider an error if they exceed the defined count per the defined unit
of time. The
Count Control sets the maximum number of events
before the error is reported. The range is 1 to 100. The Time Control
defines the amount of time that the events are counted before starting
the counting process over. Its range is 1 to 10 seconds. Note: Clip
events are defined as the start of each clip and every 10
milliseconds the amplifier is in clip thereafter. Using a high count set-
ting with a short time setting may result in clip error never being
detected.
THERMAL: Errors can be generated for excessive temperature in the
output section of the amplifier channel. The Threshold Control sets
the level that, if exceeded, will generate the error report. This control
has a range of 1 to 100%.
LOAD: If the load monitoring feature is activated, an error report can
be generated if the load impedance moves outside the pre-selected
range.
LINE VOLTAGE: The AC line voltage can be monitored and an error
generated whenever the voltage is outside of the limits set by the soft-
ware.
4 Advanced Operation