Exploring Channel EQ of Logic Pro X

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Exploring Channel EQ is the following and end of the article Explore Logic Pro X’s Channel EQ in greater depth.

Before reading this article I recommend you to read the article titled Understand the logic Pro X Channel EQ published in October 2019.

Revision

Many of you have found this first article interesting because of the information it allows you to discover or rediscover.

  • The article discusses the types of EQ, details the 8 band types and their filters.
  • Lots of usage tips for which I received thank-you emails.


So, let’s now move on to a more in-depth look at the EQ included in Logic Pro X.

Audio Analysis

Yes, I’m talking about it again in this article despite the little trick published in the first one. Let’s say that here I detail the Analyzer part.

Exploring Channel EQ
Analyzer Channel EQ

How it work?

Analyzer mode works according to the process called Fast Fourier Transform (FFT). The goal is to obtain a real-time curve for all frequencies of the incoming signal. The curve of the analysis performed is superimposed on the equalization curves if any have been defined. Analyzer curve uses the same scale as the EQ curves, which makes it possible to better recognize the important frequencies of the incoming audio signal. It also makes it easier to define EQ curves to increase or decrease frequency levels and frequency ranges.

The bands derived from the FFT analysis are scaled logarithmically: there are more bands in the high octaves than in the low octaves. As soon as the Analyzer is activated, 2 different color curves appear depending on whether you are in mono or stereo.

Left & Right signal Channel EQ
Left & Right signal Channel EQ

You can change the scale by changing the default dynamic range as shown in the image below. Drag the pointer vertically on the scale as shown in the image below to define the positioning of the analyzer curves in the EQ channel window. The range is +20 to -100 dB.

Analyzer Scale Channel EQ
Analyzer Scale Channel EQ

Concerning the global curve of the equalizer, it is possible to modify it by dragging the pointer vertically on the scale as shown in the image below.

Scale of global curve Channel EQ
Scale of global curve Channel EQ

Not forgetting, as shown in the picture below, the gain slider that increases or decreases the output level after equalization.

Output Gain Channel EQ
Output Gain Channel EQ

Personally it misses me a cursor that I appreciate a lot in the match EQ. The Apply slider which allows to invert the curve in negative or to increase it in positive. I’ll tell you more about it in a future article.

Analyzer Pre or Post ?

Analyzer button has two areas where you can interact.

  • On icon itself to activate or deactivate the Analyzer.
  • The Pre / Post button which displays the frequency curve before or after applying the equalization.
Analyzer Pre / Post
Analyzer Pre / Post

Personally, I recommend working in Pre most of the time. I recommend that you listen to the result of your equalization work rather than visualize it…

Extended parameters of the Analyzer module

Click on the display triangle at the bottom left to access the extended parameters.

Display extended parameters
Display extended parameters

Let’s take care of the Analyzer part for now. As you can see in the picture below, there are three advanced functions of the Analyzer:

The 3 advanced functions of The Analyzer
The 3 advanced functions of The Analyzer
  • Resolution allows you to choose between 3 values for the sample resolution of the analyzer:
    • Low resolution 2048 points.
    • Medium resolution 4096 points.
    • high resolution 8192 points.
  • Mode where you check either Peak or RMS understand that the analysis will be done on the peaks or the average of the internal waveform.
  • Decay in dB per second is used to determine the rate of decay of the analyzer curve. This decay mode acts according to the selected mode:
    • Peak decay in Peak mode
    • Decline in average in RMS mode.

The analyzer is a very handy Channel EQ function, it doesn’t do the work for you but guides your auditory analysis in the processing of your track. However, be careful not to equalize your tracks visually.

The trio Gain – Q – Couple and Oversampling

Other part of extended parameters
Other part of extended parameters

This is the second part of the extended parameters. The Gain-Q Couple Mode pop-up menu allows you to select the degree of Gain-Q coupling, i.e. :

  • Light allows you to make certain changes smoothly as you increase or decrease the gain.
  • medium: makes proportional changes.
  • Strong: retains most of the perceived bandwidth.
  • Asymmetric: these settings result in stronger coupling for negative gain values than for positive values. As a result, the perceived bandwidth is better preserved when you reduce the gain rather than when you increase it.
    • In Asymmetric mode, you will find the Light – Medium and Strong values
  • Proportional: Scales the bandwidth as you change the gain. Proportional widens the filter bandwidth at lower boost/mute levels and narrows it at higher settings.
Gain- Q Couple Mode and Oversampling
Gain- Q Couple Mode and Oversampling

Oversampling

The Oversampling button has a greater impact on your CPU, but provides better management of the extra high frequencies created by the EQ process.

I don’t have any advice or tips to give you for this function, just by ear, I find that some frequencies above 8 kHz are better defined without being aggressive.

Simple Processing

Processing Mode
Processing Mode

Processing: This drop-down menu includes commands to process either both parts of a stereo signal (default), or only the left (Left Only), right (Right Only), middle (Mid Only), or side (Side Only) parts of a stereo signal.

What is it for?

Very good question, let’s assume you recorded a live guitar through your sound card. The signal is mono so far it’s fine. But if you use a loop from the Apple Loops collection or another manufacturer, and more simply the stereo audio recording of your favorite Yamaha Montage synthesizer (As an example).

Well then you are confronted with multiple possibilities of sound processing by the manufacturer of the loops or the manufacturer of the synth. What in a lot of cases may not correspond to your sound processing which requires to integrate this sound source into your composition, in a word to make it simple to mix it according to your needs!

Is it possible?

Starting from the principle of a stereo file, certain sounds and frequencies, which generally result from this, the bass, are placed in the center while the other sounds are distributed in the stereo width. I base myself on the example of a drum loop. This also works on synths, many manufacturers use effects to shape and embellish the sounds.

From this observation, the Processing mode allows you to do an equalization work on the left channel of your audio loop or on the right channel. As the file is stereo we consider that the sound can also be processed as in a Mid/Side recording… (I promise I’ll talk about Mid/Side in a future article).

This makes it possible to do a treatment on the middle or edge frequencies. Understand that this brings a lot to your mix and not just the mix. For info I use this process a lot in the composition work and that as well in the music for image as in the Electro music…

Honestly spend some time to experiment !!! your ears will rediscover certain frequencies or even you will quickly understand how to avoid this muddy side in your tracks…

But then double EQ?

Yes and no because it depends on what you want to do. If you want to process the right signal differently from the left signal or process the mid in the bass and the side in the treble you will need 2 channels EQ per track.

Indeed I said yes and no what implies that with only one Channel EQ you can process Left and Right or Mid and Side!

Incredible but true!

When you select your Channel EQ in logic choose Mono Dual as shown in the picture below.

Mono dual in channel Strip
Mono dual in channel Strip

Now watch your Channel EQ more closely. In the upper middle of the plug-in there are new icons.

Mono dual buttons
  • Settings (the small cogwheel) for setting the Mono dual or L & R mode
  • Mid equalization adjustment in Mid or L mode
  • Side equalization adjustment in Side or R mode
  • Couple Mid/Side or L & R determines the influence of one on the other to be experimented because it is very interesting.

The cogwheel to get things moving

Possible Settings
Possible Settings

As you can see in the picture above, we have 2 types of choices: Stereo and Mid/Side. What is interesting is that we can mutate one of the two channels. In order to be able to concentrate on the equalization work to be done on the other one. To switch the desired channel, just click on the speaker icon that you want to deactivate. As you can see, a dot will appear on the channel to inform you that it is deactivated.

Little trick! If you click on one of the L/R or Mid/Side buttons, the equalization window of the mode you clicked on will appear.

For your information, does this display mode remind you of anything?

Surround mode

And yes the Surround mode where you can find the position of the speakers according to the chosen mode.

To activate the Surround mode, you have to modify some settings without using the menu Logic Pro X – Preferences – Advanced Tools… If it is not already done, I recommend you to check the box ” Show advanced tools”. Honestly don’t ask yourself any question, check everything including Surround!

Then on your channel strip it is important to choose the Surround mode as shown in the picture below. The selection is made for input and output.

Channel Strip Surround mode
Channel Strip Surround mode

Channel EQ Surround !!!

Yes, you can work in Surround with the Channel EQ. The settings are the same as in the Dual Mono mode adapted to the configuration of a Surround system.

Surround Channel EQ
Surround Channel EQ

With, of course, as in Dual Mono mode, the small cogwheel for the Channel EQ settings…

Channel EQ Surround Setting
Channel EQ Surround Setting

here’s a lot to be said in Surround mode certainly in a future article as many of Logic’s plug-ins are Surround including virtual synths.

The end?

Indeed I have finished exploring the Channel EQ of Logic Pro X. Unless there is a future update of Logic that would increase the possibilities of this nice EQ. How ? The field of possibilities remains open to the development teams of the Cupertino firm…

Little trick at the end: If you perform an EQ in the Channel EQ and change the plug-in with Logic’s Linear Phase EQ your settings will be copied to the new plug-in.