Gain Sharing Mixer Control Panel
Video Transcript
0:08
 Welcome back. Let’s continue from where we left off.
0:11
 Alright now let’s look at what’s happening in the Mixer itself. These are our four inputs,
0:17
 each has an LED at the top that tells us whether or not the gate is open. If the gate is not open,
0:23
 that line isn’t being mixed into the output. Right now Paul, George, and Ringo are all open, but John,
0:29
 he’s floating in and out because he’s talking so low down at -20 decibels
0:33
 that sometimes he’s gated open, and sometimes he’s not.
0:36
 Now when more channels are open, each one will be attenuated a bit more
0:40
 to keep the output level at unity gain – it’s sharing the gain across all the inputs,
0:44
 that’s why it’s called the Gain-Sharing Mixer. All coming together, right?
0:47
 Alright now each of these inputs also has a Priority Gain, this is how you compensate for quiet speakers.
0:54
 So John is really quiet, we can turn up his channel’s gain so that now when he’s speaking,
1:00
 you can see that his gate is gated open.
1:02
 Now they’re all speaking right now, and you can see that Ringo is really loud
1:05
 and he’s getting the majority of the gain, so they’re all in the mix.
1:09
 But let’s find out what happens when some of them stop talking.
1:12
 Let’s take out John and Ringo – you can see how Paul and George are being given more of the gain now.
1:18
 In fact if only Paul is talking, then the mixer gives him even less attenuation.
1:23
 but then they all start talking, and all they all start arguing
1:28
 and you can see how the gain is dropped across the board. This way the output is never going to clip,
1:34
 but when only one or two people are talking they’re given full volume,
1:36
 and nobody has to be riding the microphone gains because it’s all done automatically by this digital mixer.
1:42
 Now let’s look really quickly at some of the other options in the Mixer’s Setup now.
1:45
 This Mix section lets you mute the entire channel, or change the gain on the entire mixed output.
1:52
 The Open Threshold determines when the gate will open. If a channel’s Gain is above the number here,
1:57
 then the gate opens – this lets you adjust how sensitive you want the mixer to be in order to open a gate.
2:02
 So if I raise this threshold, their gates start to close
2:05
 because they don’t have enough gain to reach the threshold. We’ll set that back down to where it was.
2:11
 The Depth determines how much attenuation is applied to closed channels,
2:15
 so you’ll see that if I have George start speaking softly, then his gate is closed,
2:20
 and the Depth of -40 dB is how much attenuation is applied to his channel.
2:26
 The Rest Gain sets a level for all channels when nobody is talking
2:30
 that way it won’t be totally dead in between speakers so it doesn’t sound flat.
2:35
 So we can see that by having everyone start to talk very softly
2:40
 and you’ll notice that all of their channels are floating at around -30 dB.
2:46
 The threshold level lets you compensate for background noise,
2:49
 you can set this just above the background noise of the room to keep that from opening up your gates.
2:54
 And these next few knobs adjust what happens when a gate opens or closes
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 the Attack Time is sort of a fade-in time, or how long it takes to open up the channel.
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 So if I set that really high, then you’ll notice that when George is loud enough to be opened
3:11
 it takes a little bit for it to apply.
3:14
 The hold time is how long the channel stays open after the speaker stops talking.
3:18
 If I put this really high, let’s set it up to three seconds, it will take three seconds for the gate to close.
3:24
 Let’s have George stop talking. One-one-thousand, two-one-thousand, three-one-thousand.
3:29
 That’s how long it takes for the channel to turn off
3:31
 that’s really  useful if you know someone has long pauses in the middle of their sentences.
3:38
 You don’t want them to be turned off mid-sentence.
3:41
 And finally this Release Time is the fade-out, that adjusts how long it takes for a channel to close.
3:46
 Oh and here’s the Detector Time, as we mentioned earlier,
3:48
 this knob shows up and lets you adjust how long a noise has to be for it to count as an input.
3:53
 Finally – we’re almost there –the Side Chain.
3:56
 Like I said this lets you determine what type of noise opens the gate
3:59
 you can set the frequency really high so that only higher-pitched noises will open the gate
4:05
 now remember this doesn’t affect the line at all,
4:07
 it just says what the mixer is looking for to determine if the channel will open.
4:11
 There are some presets here, or you can adjust it yourself,
4:14
 or if you don’t want to use it right now just hit the bypass button.
4:17
 That’s the Gain-Sharing Automatic Mixer.
4:19
 Alright let’s break real quick right here, and come back for the next part.