Processing and Control for Professional AV Installations

Knowledge Base

Limit the dB Range for Third-Party Devices Using Symetrix System Control

Limiting a fader to a specific dB range is easy within the Composer environment, whether using a Symetrix touchscreen, ARC-Series remote, or W-series. Third-party control, however, can be a bit more difficult if the third party doesn’t have their own inherent way to accomplish this task. Thankfully, with a small bit of logic circuitry we can emulate this range control. In this example, we are trying to limit the control of this gain module’s fader.

  1. First, drag in a control fader from the Control Inputs folder in the toolkit.

  2. Then, drag in a scaler from the control processes folder. Finally, drag in a one output remote control number module from the control outputs folder.

  3. Open each module, including the gain, and set the windows to be able to view all.

  4. In the one output remote control module, choose and enter an available remote control number. Then assign that same control number to the actual fader needing to be controlled.

  5. Now right-click on the logic fader and set it up to remote control, choosing another available remote control number. Note the chosen control number cannot be the same as the gain fader.

  6. We can’t see logic activity live while offline. If we push online we will see as we move the control fader from zero to 100% the gain fader moves as well. The point is to limit the effective movement of the gain fader in relation to the full scale movement of the logic fader.

  7. We can allow the control fader to fully scale on the scaler’s input. But if we adjust the output to a desired degree, we can limit the movement of the gain fader. In this case we’ll set the low output to 50% and the high output to 85.7%. This will give us a range of 0 to -30 dB. The scaler out values can be adjusted to match your system requirements

The control fader is what would be set up for the end user to control in the programming. It in turn controls the gain fader where the actual audio is passing through. Be aware that the representation will be in percentage, not dB.

While the dB level box from the gain module can be set up to remote control, the third-party controller should be consulted about how it will represent this value.