In this video, we’ll continue to explore the Virtual View of AVX Architect and look at the Expander object. The Expander is found in the virtual view, under the “Dynamics” section of the audio processing objects. The Expander reduces the level of signals that fall below a threshold level. 
Let’s look at some of the parameters in the Expander factory panel. In the top left, the “Enable” button will turn on the expander processing. When this is off, the expander will not change the signal, acting as a bypass. The “Threshold Control” adjusts the level threshold below which gain reduction will take place. Above this threshold, no gain reduction will take place. The Gain Reduction meter will display the amount of gain reduction being applied. “Attack” adjusts the time it takes for the expander to recover after the signal level goes above the threshold.  “Release” adjusts the time it takes for the expander to respond after the signal falls below the threshold. “Ratio” will adjust the aggressiveness of the expansion. Remember that the expander can cause distortion at low frequencies when the release control is set to low values. Unless you particularly need the expander to attenuate very quickly, set the release control to a reasonably high value.
At the top of the factory panel, we have our usual object name, lock button, and selection mode switch. On the right, the “Properties” window has the usual naming, workspace location, and DSP allocation options. The “Options” section contains the usual channel count of the object block. Dynamics processing objects like compressors or gates are limited to a maximum of 128 channels. When using multi-channel expanders, they function like independent expanders with common controls. Every signal is processed based on its own signal level. The “Side Chain” option is off by default. Turning it on will add an input source to our expander object labeled as side chain. The Expander will then listen to our side chain input, and processing on our main input source will be controlled and dynamically affected by the sidechain input. When using side chain on multi-channel expanders, the sidechain input will control the expansion of all channels.