Logic Pro and Stereo Files (Part.2)

Let’s start for the second part on “Stereo Files in Logic”.
We’ll consider how Logic Pro manages this point and the plugins available to shape this aspect.

SOME PRELIMINARY INFORMATION ON LOGIC’S CONSOLE

According to you, is there any difference on the knob with the red square on a mono channel strip,

And the one on a stereo channel strip ?

And the answer is….YES !
On a “Mono” channel strip this pot is dedicated for panning the audio signal within the stereo space… Nothing very complicated.
However, when ones considers a “stereo channel strip” its function is different and it become a selector of the “balance” of the signal.

This means that it doesn’t concern anymore the panning in term of space but rather it allows to adjust the level of the audio signal between the 2 stereo signals.
In summary, it doesn’t concern anymore the place in the stereo field but it is restricted to modulate the gain or level of the signals !

Nothing is better than an example. Have a look on a short stereo track I’ve created.

A sample of bass line has been recorded and is located on the top of the region while on the bottom on the image the vertical lines correspond to the metronome clicks.
Everything crystal clear ? Ok, let’s proceed

When the track is played with the “pan pot” at “0” (center) you ear this (listen to it with headphones, it makes it more obvious)

When the track is played with the “pan pot” at “-64” (fully left)

You ear this.

And finally, when the track is played with the “pan pot” at “+ 64” fully right)

You ear that.

The above-mentioned examples show clearly that we’re dealing with level and not stereo placement. Would it have been the case, the pan made would lead to ear both the “cliks” and the bass line on the right with the same level.

CAN WE MODIFY THE THE “PAN” OF A STEREO FILE ?

The answer is YES but needs to use a native Logic plugin called “Direction Mixer” located in the section “Imaging”.

Now here’s a Logic’s session with my audio file and the plugin inserted.

Hereafter you may download the Zipped file I’ve generated and try by yourself. To make a left panning, just follow the instructions of the plugin (as shown below)

and the opposite for a right panning.

OTHER LOGIC TOOLS DEDICATED TO STEREO

Stereo Spread

This plugin allows you to enlarge the stereo space on selected frequencies.

While the range is from 20Hz to 20kHz, keep in mind that generally speaking the “low frequencies would be located at the center of a mix. Be careful not to work with frequencies below 500-600Hz at the minimum.

While this plugin is very contributive, it may also induce “phase issues”.
In addition, it can also be used on a single track of a Logic project.

Gain

Personally speaking I felt in love with this plugin that can be considered really as a “Swiss knife”.

While its initial function is obviously to manage the “Gain” levels (very useful when ones deals in Gain Staging during mixing isn’t it ?) it can make a lot of things when inserted on a stereo track.

Some of the properties of this “Gain Plugin” are listed below :

• Swapping the right and left channel of a file (Swap L/R)

• Invert the phase of 2 channels (Phase invert) very contributive to detect phase issues in overheads of drums for example.

• Converting a stereo file into a mono one by a simple click on the Mono button.
  The “Gain” plugin acts by summing the 2 channels of the stereo file and is very attractive to perform “mono file” in Bass synths in Electro music Mixes.

It contributes also to reveal phase issues between the 2 channels : when the plugin is “On” listen carefully : if some “sound information” are lost that means that there are some phase issues.

This function looks very essential for my way of mixing.

Direction Mixer (again !)

In addition to be able to make a “Pan” on a stereo file, it may also enlarge or reduce the amplitude of the signal placement. This property is quite similar to the ones of the Stereo Spread plugin. However, don’t forget that its primary function is to make stereo placement and not to enlarge or reduce the stereo space.

A value of 1 is the default setting ; a value of 2 represents the maximum enlargement…but may create Phase cancellation issues as well. This shows clearly that stereo enlargement has to be dealt with high caution in a mix.

The Direction mixer plugin can also convert a stereo track in mono (like the Gain Plugin). When the value of the spread is at “zero” you’re in “Mono”
Personally speaking, I often use such properties to “compact” the stereo of synths by setting the value at “O.8” as an example.

Multimeter

This plugin is full of options, but we’ll restrict our topics on Stereo.

The « Goniometer » gives information on the stereo image. More thin will be the “center form” more thin will be the stereo image and conversely. This can be seen clearly on the screenshot below.

Well guys, it seems that we’ve completed our second paper regarding the Stereo in Logic Pro ! Please don’t hesitate to post comments and/or suggestions…

Talk to you soon, take care.