One cause of feedback is open microphones on the stage. You can use the Noise Gate in your ToneMatch mixer to shut down microphones that are not being used. When the sound presented to the microphone is loud enough (it reaches a predefined threshold), the gate will open allowing sound through.
Initial Setup for a Microphone
You can use the Comp/Gate Noise Gate to automatically turn off a microphone when it is not being used. This can reduce unwanted background noise and increase the gain-before-feedback of your system.
The Noise Gate prevents signals below a certain volume level (threshold) from reaching the outputs of the mixer. You set that certain volume level by setting the Threshold parameter.
- Press the CHEDIT button on the channel you want to control
- Turn the Rotary Selector to COMP/GATE
- Under the display, turn the Type button so you can see the menu
- Select Noise Gate
- Set the Thresh to -40.0dB
- (T4S/T8S) Leave Ramp/Speed at 50% (T4S/T8S)
If the Noise Gate cuts off the microphone even while you are speaking directly into it try setting the Thresh to -50.0dB. You may have to experiment with the Thresh and Speed to get the Noise Gate to work with different vocalists and microphones.
- Rotate the Thresh control to adjust the input threshold (trigger) level from –90 dB to –30 dB.
- -90 dB is the most sensitive setting letting in the most sound. As you move toward -30 dB, it will require more volume to open the Noise Gate
- Rotate the Speed control to set the gate closing speed to any value from 0% (fastest) to 100% (slowest).
- You may find a slower Speed (higher value) gives a more gradual the cut-off, and this may sound more natural as a singer naturally lowers their volume at times.
- Ramp (T4S/T8S only)
- Press the Speed control button to access the Ramp control. Press the Ramp control button to switch back to Speed.
- Rotate the Ramp control to adjust the slope of the gate from 0% (horizontal) to 100% (vertical). The Ramp parameter is the slope of the opening gate allowing signal through. It can be thought of and perceived through time. A steep ramp (100%) will open quick and aggressively, while a shallow ramp (0%) opens slow and more gradually. This is different from Speed which affects how quickly the gate clamps down after the signal has passed.
- You may set the Ramp closer to 100% so the beginnings of phrases are allowed through rather than ramping up the volume slowly.
Video with T1
The same principles apply to the T4S/T8S, but they have the Ramp control.
Here's a quick video to show you how to use the Noise Gate with the T1. If you have the T4S/T8S, see the notes above about working with the Ramp control.
For more tips see:Microphone Feedback