Crown Audio IQ-P.I.P.-SMT - Manual (Page 14)

Page 14
IQ P.I.P.–SMT
Output Limiter: Turns this
function on/off.
Threshold ::::: Sets the threshold,
in dB, above which the limiter
acts. The level is based on the
scaled output voltage monitors
(see Section 3.9). The range is
from 0 dB to –40 dB.
Attack Time: Sets the attack
time of the limiter. The attack
time is defined as the time it
takes the limiter to attenuate the
input signal by 10 dB. The range
is from 10 milliseconds to 30
seconds.
Release Time: Sets the release
time of the limiter. The release
time is defined as the time it
takes the limiter to increase the
input gain by 10 dB. The range
is 100 millisecond to 30
seconds.
Ratio: The compression ratio is
fixed at
∞
:1.
3.11 IOC Event Monitor
The Input/Output Comparator (IOC ® )
of each channel of the amplifier can
be monitored by the
IQ System. The
IOC circuitry acts as a sensitive dis-
tortion meter to provide you
proof of
distortion-free performance. If distor-
tion of any kind equals or exceeds
0.05%, the
IOC circuit will cause an
indicator on the front of the amplifier
to flash. By monitoring these events,
the
IQ System can flash an indicator
on the screen of the host computer to
alert a user that distortion is occur-
ring.
3.12 Prolonged IOC Warning
A “trigger” can be set that will cause
a warning message to appear on the
host computer’s screen if too many
IOC events occur over a specified
length of time. Three parameters con-
trol this feature:
IOC Error Detect: Turns this
function on/off.
IOC Error Time: Sets the time
interval over which IOC events
will be counted. The range is
from 1 to 10 seconds.
IOC Error Count: Sets the
number of IOC events that must
occur during the preceding time
interval before a warning
message is displayed.
Note: An
“IOC event” is one complete on-
off-on cycle. The range is from 1
to 100 events per unit time.
3.13 ODEP Level Monitor
The Output Device Emulation Protec-
tion
(ODEP ® ) level of each channel of
the amplifier can be monitored by the
IQ software. This level represents the
percent of available thermodynamic
energy that is currently being used.
When the
ODEP level reaches 100%,
the amplifier cannot produce any
more power and
“ODEP limiting” will
begin to limit the drive level to the out-
put devices, thereby protecting them
from too much stress. (See the
amplifier’s
Reference or Owner’s
Manual for more information about
ODEP.)
3.14 ODEP Conservation
The effects of “ODEP limiting” the
drive level of the output devices as
described in Section 3.13 above are
very audible. To overcome this, an
ODEP conservation limiter is avail-
able to proportionally limit the input
audio signal as the thermodynamic
energy reserve of the amplifier is con-
sumed. This helps to prevent the am-