ALFAtron ALF-DSP88-U, Руководство пользователя

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ALF-DSP88-U
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Fig.3.2 Expander
The expander has the following control parameters:
Threshold: The expander activates only when the signal exceeds this threshold (allowing the transmission of the signal). As a
standard practice, the signal is often set at the ambient noise level
Ratio: Ratio refers to the slope below the threshold point on the gain curve. When the slope is set at a high level, gating will
activate.
Attack:
Attack refers to the time that the expander will wait before activating when the input signal exceeds the threshold.
Shorter attack time allows to start the expander more quickly.
Release time: Release time refers to the delay in time required for the gain to be restored to normal when the input signal
drops lower than the threshold.
No matter the starting time or the release time, it just helps to reduce the speed of gain attenuation. That is to say, the
speed of the gain from -40dB to 0dB is slowed down due to the influence of Attack. The Attack time and Release time is
unrelated to the threshold. If the signal level falls below the threshold, the Attack time and Release time will have their own
respective influence on gain attenuation; when the signal level rises above the threshold, the gain attenuation produced by
the expander will disappear in accordance with the speed controlled by the Release time. When the gain attenuation is
reduced to 0dB, the expander will stop expansion. Later, when the signal reduces to below the threshold, the expander will
start again, and the release time will begin to work.