Operation; Protecting Your Speakers; Startup Procedure; Precautions - Crown I-Tech 4x3500HD DriveCore Series Operation Manual

6 Operation

6.1 Protecting Your Speakers

6.2 Startup Procedure

It's wise to avoid clipping amplifier signals at the input and output. Not When first turning on your amplifier, follow the procedures in the
only does clipping sound bad, it can damage loudspeakers. To prevent Quick-Start Guide on page 4 (stereo) or page 5 (bridge-mono).
clipping, use System Architect software's Level Max suite to enable or
If you ever need to make any wiring or installation changes, don't for get
display the peak voltage limiter and average power limiter in your
to disconnect the power cord.
amplifier's built-in DSP. That way, no matter how strong a signal your
mixer produces, the amplifier output will not clip. Set the limiter
For help with determining your system's optimum gain structure
threshold so that at full level no components in the audio signal chain (sig nal levels) please refer to the Crown Amplifier Application Guide,
are clipping, the amplifier input and output is not clipping, and the
available online at www.crownaudio.com.
attached loudspeakers at properly protected according to the mnfg's
rec'd specifications.

6.3 Precautions

Your amplifier is protected from internal and external faults, but you
Also, avoid sending strong subsonic signals to the amplifier.
should still take the following precautions for optimum performance
High-level, low-frequency signals from breath pops or dropped
and safety:
micro phones can blow out drivers. To prevent subsonic signals, use
one of these methods:
1. Before use, your amplifier first must be configured for proper
operation, including input and output wiring hookup. Improper
• Insert a highpass filter between mixer output and amplifier input (or
wiring can result in serious operating difficulties. For information
between mixer and limiter).
on wiring and configuration, please consult the Setup section of
• Use the I-Tech's onboard DSP to set up a highpass filters. this manual or, for advanced setup techniques, consult Crown's
Amplifier Application Guide available online at
• Switch in highpass filters at your mixer. Set the filter to as high a
www.crownaudio.com.
fre quency as possible that does not affect your program. For example,
try 35 Hz for music and 75 Hz for speech. On each mixer input channel,
set the filter frequency just below the lowest fundamental frequency of
that channel's instrument.
• Note: An amplifier reproduces the signal present on the input.
Therefore, if you send clipped or squared wave signals to the input, it
will recreate this on the output possibly damaging your loudspeakers.
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I-Tech HD DriveCore Series Power Amplifiers I-Tech HD DriveCore Series Power Amplifiers
6 Operation
2. Use care when making connections, selecting signal sources and

6.4 Front Panel Controls and Indicators

controlling the output level. The load you save may be your own!
Many of these functions can be disabled using
3. Do not short the ground lead of an output cable to the input signal
Blackout Mode (a selection in the Advanced
ground. This may form a ground loop and cause oscillations.
Menu, Section 7.2).
4. WARNING: Never connect the output to a power supply,
A. Cooling Vents
battery or power main. Electrical shock may result.
5. Tampering with the circuitry, or making unauthorized circuit
B. LCD Display Screen
changes may be hazardous and invalidates all agency listings.
6. Do not operate the amplifier with the red Clip LEDs constantly
flashing.
7. Do not overdrive the mixer, which will cause clipped signal to be
sent to the amplifier. Such signals will be reproduced with extreme
accuracy, and loudspeaker damage may result.
8. Do not operate the amplifier with less than the rated load
C. Power Switch
imped ance. Due to the amplifier's output protection, such a
configura tion may result in premature clipping and speaker
damage.
9. CAUTION – SHOCK HAZARD: Potentially lethal voltages
exist at the output connectors when the amplifier is
turned on and is passing a signal.
Remember: Crown is not liable for damage that results from
overdriv ing other system components.
Operation Manual Operation Manual
D. USB 2.0 Connector
Accepts a USB drive to transfer presets, device files,
and update firmware from the drive to the amplifier
DSP, and vice versa.
E. Fault Indicator
Red LED, one per channel, flashes when the
Front-to-rear forced airflow through foam dust filter
ampli fier output channel has stopped operating.
Usually this means that the amplifier must be
serviced.
Integrated 4.3" color LCD with backlight, displays
amplifier settings.
F. Thermal Indicator
Red LED, one per channel, illuminates when the
The LCD Display Screen and its controls let the user
channel has shut down due to thermal stress or
adjust the amplifier's attenuation and muting,
overload.
con figure the amp, set up and view error monitoring
(such as temperature and load supervision), and
G. Clip Indicator
recall DSP presets.
Red LED, one per channel, illuminates when the
channel's output signal reaches the onset of audible
clipping. The Clip Indicator also will illuminate
Push-on/push-off switch glows green when AC
dur ing Thermal Level Control (TLC) limiting. The
power is present at the power cord and the amplifier
Clip Indicator can be turned off during Blackout
circuit breaker is in the "on" position.
mode.
Figure 6.1 Front Panel Controls and Indicators
H. Level Control (Encoder)
M. Ready Indicator
Speed-sensitive, 0.5 dB steps, range 0 to –100 dB.
Green LED, one per channel, illuminates when the
This knob affect the Channel 1-4 output levels. Also channel is initialized and ready to produce audio
Menu items and adjust parameter values that are out put.
displayed on the LCD control screen.
N. Power Indicator
I. Menu/Exit Button Blue LED indicates amplifier has been turned on and
"Menu" enters the main menu. "Exit" leaves the AC power is available. The LED will flash when the AC
menu. line voltage is 15% above or below the nominal rated
range. This indicator can be turned off in Blackout
J. Prev Button
mode.
Selects the previous item in the menu.
O. Data Indicator
K. Next Button
Yellow LED indicates network data activity. Data
Selects the next item in the menu.
indicator flashes only when the amplifier is polled for
L. Signal Indicators data, or is polled to see whether it is online. This
indicator can be turned off in Blackout mode.
These can be disabled during Blackout mode. Three
green LEDS per channel indicate the ampli fier's P. Bridge Mode Indicator
input and output signal levels. From top to bot tom Yellow LED illuminates when the amplifier is set to
the LEDs are Bridge-Mono mode.
–10 dB: amplifier output is 10 dB below clipping.
–20 dB: amplifier output is 20 dB below clipping.
Signal: selected input signal is above –40 dBu.
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