Crown Audio I-Tech Series Advanced Operation, I-TechSeries Power Amplifiers, page, User Presets

I-Tech Series Power Amplifiers

4 Advanced Operation

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 or System Architect software, and connected to the amplifier Network Connector 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 preset is in use.

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 0dBFS to –60dBFS with 0.5dB 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

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. System Architect has a separate meter for gain reduction.

4.6.10 Amplifier Information

Information about the amplifier is stored in the software system inven- tory 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 control software Error Window. The IQwic software offers many options to further report errors, including audible alerts, printout, email, pager, serial port and fax. System Architect has logs as well as email. 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.

Operation Manual page 25