| ## Gain Reduction
The example shows different audio groups: The left group runs in Multichannel mode, the other two groups in 5.1 (yellow marker) and Stereo formats (green marker). Move the mouse accross the display elements to get the corresponding descriptions.
The Gain Reduction displays external gain reduction data, for example the compressor activity of a mixing desk channel, that can be fed to the TouchMonitor via its Network interface and TCP/IP. Suitable gain reduction data can be streamed by dynamic processors used in audio equipment that was prepared for this task. Before using the Gain Reduction instrument, different parameters in the menu must be configured in order to establish communication between external equipment sending Gain Reduction Metering data and the TouchMonitor. Also a threshold value marker can be defined to divide the GR scale into e. g. operation range and tolerance range sections with different colors. Only one Gain Reduction instrument can be used in each audio group. In any audio group (except "Multichannel"), this Gain Reduction instrument will have only one GR bargraph. However, in an audio group set to "Multichannel" mode, the number of bargraphs shown in the GR instrument will reflect the channel width of this multichannel audio group. Please note:: In order to use more than one Gain Reduction instrument (= more than one audio group) or to use Surround formats for a preset, the Multichannel licence (SW20001) must be installed in your TouchMonitor unit.