Справочник Пользователя для Crown Audio IT9000 HD

When fi rst turning on your amplifi er, follow the procedures in the 
Quick-Start Guide on page 4 (stereo) or page 5 (bridge-mono).

If you ever need to make any wiring or installation changes, don’t for get 
to disconnect the power cord.

For help with determining your system’s optimum gain structure 
(sig nal levels) please refer to the Crown Amplifi er Application Guide, 
available online at www.crownaudio.com.

Your amplifi er is protected from internal and external faults, but you 
should still take the following precautions for optimum performance 
and safety:

1.  Before use, your amplifi er fi rst must be confi gured for proper 

operation, including input and output wiring hookup. Improper 
wiring can result in serious operating diffi culties. For information 
on wiring and confi guration, please consult the Setup section of 
this manual or, for advanced setup techniques, consult Crown’s 
Amplifi er Application Guide available online at 
www.crownaudio.com.

It’s wise to avoid clipping the amplifi er signal. Not only does clipping 
sound bad, it can damage high-frequency drivers. To prevent clipping, 
use System Architect software’s Level Max suite to enable or display 
the peak voltage limiter and average power limiter in your amplifi er’s 
built-in DSP. That way, no matter how strong a signal your mixer 
produces, the amplifi er output will not clip. Set the limiter threshold so 
that mixer signals above 0 dB or 0 VU on the mixer meters do not quite 
drive the amplifi er into clipping.

Also, avoid sending strong subsonic signals to the amplifi er. High-
level, low-frequency signals from breath pops or dropped micro-
phones can blow out drivers. To prevent subsonic signals, use one of 
these methods:

• Insert a highpass fi lter between mixer output and amplifi er input (or 
between mixer and limiter). 

• Use the I-Tech’s onboard DSP to set up a highpass fi lters.

• Switch in highpass fi lters at your mixer. Set the fi lter to as high a 
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 fi lter frequency just below the lowest fundamental frequency of 
that channel’s instrument.

2.  Use care when making connections, selecting signal sources and 

controlling the output level. The load you save may be your own!

3.  Do not short the ground lead of an output cable to the input signal 

ground. This may form a ground loop and cause oscillations.

5.  Tampering with the circuitry, or making unauthorized circuit 

changes may be hazardous and invalidates all agency listings.

6.  Do not operate the amplifi er with the red Clip LEDs constantly 

fl ashing. 

7.  Do not overdrive the mixer, which will cause clipped signal to be 

sent to the amplifi er. Such signals will be reproduced with extreme 
accuracy, and loudspeaker damage may result. 

8.  Do not operate the amplifi er with less than the rated load 

imped ance. Due to the amplifi er’s output protection, such a 
confi gura tion may result in premature clipping and speaker 
damage.

Remember: Crown is not liable for damage that results from 
overdriv ing other system components.