Trascrizione Video
TM-30 Pro: Procedura guidata di feedback
5m 11s
0:07
Let’s face it. Feedback is annoying – for you, AND your audience.
0:11
But if you’ve got a loudspeaker, a microphone, an acoustic path between the two and enough gain, eventually you’re going to get feedback.
0:21
The trick is to set up your system so the gain you need for the performance is below the "threshold of feedback".
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We refer to this as a “stable” system.
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The TouchMix-30 has a remarkable Feedback Wizard that can help manage any feedback …
0:33
… but before we look at that, let’s review some best practice ideas to mitigate feedback in your setup.
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Selection and placement of loudspeakers and microphones, room acoustics, and the performer’s microphone handling technique …
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… can all contribute to how likely it is that feedback will happen.
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Here are a few tips to deal with these factors:
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First, the Main PA loudspeakers should be forward of the microphones.
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The vocal stage monitors should usually have low-frequencies below 100 Hz rolled off, and should be aimed at the performer’s ear level.
1:06
As for the microphones, try to keep the microphone pointed away from monitors.
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And try to avoid cupping the head of the microphone with your hands, as this can cause feedback as well.
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When EQing the mics, use a high-pass filters on everything that doesn’t actually have desirable low-frequency content.
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Finally, be aware that if the stage has a rear wall with a hard, reflective surface, this might contribute to feedback.
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Also, avoid using excessive EQ boost on input channels or outputs.
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Let’s say you’ve done all these things right but you’ve still got a feedback problem.
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That’s where the TouchMix-30’s Feedback Wizard can help.
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You see, Feedback doesn’t happen all at once and at all frequencies.
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It occurs at frequencies where there is a narrow peak in the response of the total system.
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If we can find these frequencies and use very narrow filters, then we can get lots more gain before feedback.
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In other words, our system will be stable.
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So let’s take a look at how the TouchMix-30 manages feedback.
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First we’ll select an output channel – it could be the Main L/R or one of the Auxiliaries.
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Now let’s press the “Anti-Feedback” button.
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Every output of the TouchMix-30 has a 12-band Anti-Feedback filter system.
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These filters are very narrow so they don’t have much effect on the overall tonal balance.
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Their purpose is to eliminate feedback. You could adjust these manually, or you could start the Feedback Wizard.
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If you want to zero out all the filters before you begin, touch the “Reset” button.
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Also make sure the Filters switch is set to “In”.
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In order to kill feedback you actually have to cause a little bit of feedback.
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Many professional engineers refer to this as “ringing out the system.”
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This process will result in some brief instances of feedback that could be annoying to some, …
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… which is why you should be sure to do this before the audience has entered the venue.
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With that in mind, it’s time to let the Wizard work its magic.
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Touch the “Feedback Wizard” button and you’ll see some instructions on preparing your system.
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The Feedback Wizard automates the very same process an experienced operator would use to get maximum gain before feedback.
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Read and follow these instructions, then press Start.
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You’ll notice the fader will begin creeping up on its own. As the gain increases, the first feedback frequency rears its ugly head.
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This window will display the frequency of the feedback and the wizard will apply a filter.
3:30
If the frequency starts “taking off” too much, the wizard will bring the fader down – just like an experienced sound engineer would.
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Then the wizard will start looking for the next frequency.
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For most situations you won’t need to apply all twelve filters, so feel free to exit the wizard before it uses them all.
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When you do, the main fader will return to its starting position. Then you can repeat this process for the other outputs.
3:55
The Feedback Wizard will only use filters that have a cut of 0.0 dB, so the Wizard can’t change any filters that you have already set.
4:03
These filters are live and editable – so you can adjust them after they’ve been created.
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You can quickly toggle a particular filter on or off by tapping its label, or you can adjust its frequency and cut individually using these knobs.
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You can also increase and decrease all of the filters at once by adjusting the “Filter Depth” control, or widen the filters with the “Filter Q” control.
4:28
Here’s one more thing to know. The mixer keeps looking for feedback frequencies all the time, even after you’ve stopped the Wizard.
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If it detects new feedback, it will still display the trouble frequency here, but it won’t apply a new filter unless you touch the “Manual Kill” button.
4:45
Certain sounds like a synthesizer that’s holding a single note or a sustained, feedback guitar note seem like feedback to the wizard.
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So the Manual Kill button keeps you in control without notching out any of your music.
4:49
The Feedback Wizard. Just another way the TouchMix-30 Pro goes beyond mixing to give you great results.
Descrizione della lezione
TM-30 Pro: Procedura guidata di feedback
5m 11s
Scopri come la procedura guidata di antifeedback può aiutare a gestire qualsiasi problematica.
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TM-30 Pro: Procedura guidata di feedback
5m 11s