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IQ–P.I.P.–DSP Programmable Input Processor with DSP for IQ Systems

Reference Manual

output limiters are controlled by the

IQ System and has

five parameters:

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 4.4). 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 milliseconds to 30 seconds.

Ratio:

The compression ratio is fixed at

:1.

4.14 Auto Standby

The Auto Standby feature automatically turns off the
high-voltage supplies of the amplifier when no audio
signal is detected at the input for a predetermined
period of time. The channels are controlled
independently. Using it, many

IQ Systems can pay for

themselves in just a few years due to reduced energy
costs. There are four parameters which control this
feature:

Auto Standby:

Turns this function on/off.

Standby Level:

Sets the level, in dB, below which

the high voltage supply of an amplifier channel will
be turned off. The range is from +16 dBu to –40
dBu.

Standby Time:

Sets the time, in minutes, that the

input signal must remain below the Standby Level
before the channel’s high-voltage supply is turned
off. The range is from 0 to 255 minutes. A setting of
0 (zero) yields a turn-off delay of approximately 2
seconds to facilitate setup of the function.

Use Turn-On Delay:

Enables or disables the IQ

address turn-on delay. This is a delay that prevents
all the amplifiers from turning on at the same instant
and tripping power breakers when an “all amps on”
command is issued by the

IQ System. The turn-on

delay is calculated by: 10 msec x IQ address
value. It may be desirable to disable this turn-on
delay when using the Auto Standby feature so that
the first syllable of speech is not missed when a
voice page suddenly causes the Auto Standby
function to turn a high-voltage supply back on.

4.15

ODEP Limiter

The effects of

“ODEP limiting” the drive level of the

output devices (as described in Section 4.5) are very
audible. To overcome this, an

ODEP limiter is available

to proportionally limit the input audio signal as the
thermodynamic energy reserve of the amplifier is
consumed. This helps to prevent the amplifier from
“

ODEP limiting” the drive level of the output devices as

described earlier. In the majority of cases, limiting the
input signal produces a very smooth sound. And since
the input signal is only limited when and to the degree
necessary, it is very difficult to detect. There are four
parameters which control this feature:

ODEP Conservation:

Turns this function on/off.

ODEP Trigger Level:

Sets the

ODEP level, in

percent, above which the conservation limiting will
begin. The range is from 1 to 100%.

ODEP Conservation Amount:

Sets the amount,

in dB, that the input signal level will be attenuated
for each percentage point that the

ODEP level

exceeds the trigger level. The range is ½ to 6 dB in
½-dB steps.

ODEP Conservation Release Time: