dbx 1066, Operation Manual

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Operating controls
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Figure 4 illustrates the protective action of the PeakStopPlus™ limiter. The signal with the thin line
weight represents an unaltered input signal. As you can see, peaks of the input signal exceed the clamp-
ing level. The signal with the heavier line weight represents the output signal. The peaks of the input sig-
nal which exceeded the clamping level are not allowed to exceed this level at the output. This instanta-
neous protective action is invaluable for driver protection in speaker systems and for digital recording
where it is desirable to record as “hot” as possible, while still avoiding the disastrous result of running out
of headroom. Following this clamping action, Intelligent Predictive Limiting™ takes over, typically within
5ms, as long as the input signal continues to exceed the PeakStopPlus™ threshold. This program limiter
quickly attenuates the input signal to a level safely below the clamping level, typically 2 dB lower than the
clamping level. The PeakStopPlus™ level control is calibrated to this lower level, so if an absolute ceil-
ing is required, set the level 2 to 3 dB below the front panel setting.
As implied by the name, the attack and release times of the Instantaneous Transient Clamp™ are zero,
while the Intelligent Predictive Limiting™ attack and release times are program-dependent. That is, for
larger excursions over the threshold, the attack time speeds up, and for smaller excursions over the
threshold, the attack time slows down. Similarly, for large excursions over the threshold which cause
more PeakStopPlus™ gain reduction, the release time increases and is roughly proportional to the
amount of gain reduction that occurred.
So, as you can see, dbx’s exclusive PeakStopPlus™ is a technically advanced and superior limiting
scheme for unrivaled system protection.
Figure 4: Protective Action of the PeakStopPlus™ Limiter
Time
Output Signal
Input Signal
Output Signal
Intelligent Predictive Limiting™
Release Time
Attack Time
}
2 dB Typically
Absolute ceiling of the Instantaneous
Transient Clamp™
Intelligent Predictive Limiting™ Level