Output Processing
| Site: | QSC |
| Course: | MP-M Series Training |
| Book: | Output Processing |
| Printed by: | Guest user |
| Date: | Tuesday, 3 December 2024, 9:51 AM |
Description
Video Transcript
00:07
It’s time to configure our output processing.
00:09
From our Setup Wizard, let’s select our Output Settings option.
00:14
We've already seen this screen before, and we’ve already established the general setup, sources, and presets,
00:19
so we’re mostly looking at these last four pages: GEQ, Anti-Feedback, Loudness, and Limiter.
00:28
The Graphic Equalizer gives you control over 28 frequency bands,
00:31
which you can enable or disable with the “In” switch at the top.
00:36
You can also engage the RTA on this screen to see an active visualization of the live output.
00:41
The Anti-Feedback feature is designed for zones with open microphones that may experience feedback.
00:47
This is a great tool to ring out the room and initially identify problem frequencies,
00:52
and then use it as a way to babysit the room’s feedback
00:54
when those open microphones start moving around in the space.
00:58
Now, many business music systems don't have any microphones and in that case,
01:02
there’s no need for Anti-Feedback.
01:05
But if there is a microphone in a zone that is prone to feedback, let me show you how to deal with it.
01:11
Start by pressing the feedback wizard on the Anti-Feedback screen.
01:15
Follow the instructions and set the microphone or microphones in position
01:19
and the levels for input and output channels just a little bit below the threshold of feedback.
01:25
Then hit the Start button.
01:27
The Wizard will slowly raise the level of the output channel until feedback begins.
01:32
Then the wizard will identify the frequencies,
01:35
apply a very narrow notch filter and move on to find the next frequency.
01:40
There are 12 filters available but usually you should achieve adequate gain before feedback
01:45
if you stop the process after 4 to 6 filters have been used.
01:49
The Loudness page is here to help you compensate
01:52
for the way our ears perceive tonal balance at different levels of sound.
01:57
Generally speaking, as level decreases,
02:00
more low-frequency is needed to maintain a perception of the same tonal balance.
02:05
So something that sounds fine at high volumes, will seem “thin” and lacking bass at lower volumes.
02:11
Here’s how to address that in the Loudness compensation.
02:15
Start by engaging the Loudness function.
02:18
Set your output level at the typical operating position
02:21
where there should be no loudness compensation applied.
02:25
Set your Threshold level slightly below this.
02:28
When the volume gets turned up,
02:30
your ears respond naturally and the perceived low frequency content actually increases.
02:36
When the volume gets turned down and it goes past the Threshold,
02:40
the Loudness circuit responds
02:41
by boosting the low frequency content following the Equal Loudness Contours
02:46
which helps the perceived low frequency stay constant regardless of the volume.
02:51
If you want to increase the low frequency response of the circuit you can increase the Scale.
02:57
Finally we can set the Limiter, which will prevent the audio from exceeding a preset threshold.
03:02
Before you use the Limiter,
03:04
the best gain staging practice is to set the minimum and maximum levels back in your setup page FIRST,
03:10
as this processing will be applied before it reaches the limiter.
03:14
But even with those maximum levels in place, you never know if a really hot signal will come in
03:20
—especially if you swap out a source device—
03:22
so it’s a good idea to use a Limiter to manage any peaks that exceed your maximum desired level.
03:28
By now you should be pretty familiar with the tools for engaging the Limiter,
03:32
putting it in Simple mode for an easier interface,
03:35
or fine-tuning the limiter’s threshold, attack and release time.
03:39
Once you’ve adjusted all your input and output settings,
03:42
we’ll return to our trusty Setup Wizard and check these off.
03:45
All that’s left now is to setup the system to be controlled, which we’ll look at in the next video.
Downloads and Links
Lesson Description
Walkthrough of all processing features available for output channels on the MP-M Mixer.