Mixing Essentials: Imaging In Logic Pro askaudiomag.com June 1, 2015

Well placed sounds and instruments can help make your mix stand out from the

crowd. Joe Albano shows how panning, direction and stereo spread in Logic Pro

that can make a positive difference.

Plain stereo panning is one of the most basic things we do when mixingplacing

instruments and voices in various locations between the speakers can really help

to open up a mix, enhancing clarity and depth, if done well. In Logic, there are a

number of things to deal with when it comes to panning, along with plug-ins that

affect positioning and stereo imaging, found under the category of Imaging. Lets

take a look at some basic considerations.

Fig 1

Imaging controls in Logic.

Pan, Panner, Pan Pot...

The most basic panning is, of course, done with the Pan knob (or Pan Pot) in

each Channel Strip. Of course, you already knew that, in the physical world, Pan

Pot is short for Panoramic Potentiometertwo volume pots controlled by one

knob. But even this most straightforward application has some quirks in Logic,

so lets start there.

Assuming a Stereo mix, mono Channel Strips have a classic Pan knob, which

works as expectedpan left (for example), and you feed more signal to the left

speaker and less to the right, and vice versa.

Fig 2 Pan/Balance knobs in Logic.

At center, the signal is at equal volume in both speakers, creating the illusion of

being centered in the mixthe phantom center. All the way left or right is

called hard panning, but, since most tracks in a mix have at least some level in

both speakers, a hard-panned track will lack the subtle phasing that occurs in

playback from having two physical sources for the same sound, and sometimes

might not blend into the mix as well as it could. Many engineers will pan to

about 90% left or right, or so, when they want a wide pan position.

Pan vs. Balance

But stereo tracks in Logic work a little differently. In a Stereo Channel Strip, the

Pan knob is not really a panner, per se, but a Balance control. When you pan

away from center, it doesnt shift the overall image to the left and right, as you

might expectinstead, it re-balances the left & right channels. While this does

have the effect of moving the signal to the left or right, whats actually happening

is that one side of the stereo signal is being reduced, and the other increased in

volume. So, if you pan all the way left, youll be hearing only the left side of the

(formerly) stereo signal, on the left, not both left & right squeezed together on

the left, as you might expect. Having a Balance control is important for stereo

tracks, but many times, what you really need is a true Stereo Panner, which will

let you pan a stereo track to one side, maintaining the stereo field, though it will

narrow gradually as you pan, until, at hard left or right, youd have both

channels, in mono, on that side of the mix, rather than only the left channel

alone, which is what you get with Logics stereo Balance knob.

This can be a gotcha with stereo tracks like strings or piano, where there may be

more level from, say, high notes on one side, and low notes on the other.

Attempting to pan such a track toward one side of the mix will unintentionally

change the instruments balance, reducing the level of some notes, and

increasing the level of others, slightly altering the balance and dynamics of the

performance.

One Direction (Mixer)

Some DAW mixers let you choose between having the pan knob on a stereo

channel strip function as either a Balance knob, as in Logic, or a true Stereo

Panner, like I described above. Logic offers no such choicemono tracks have

the Pan knob, stereo tracks the Balance knob. But you neednt reach for that

third-party panner plug-in just yetLogic does offer true stereo panning, via its

included Direction Mixer plug-in, found under the Imaging category.

Fig 3 Logics Direction Mixer plug-in.

The Direction knob, at the bottom, provides true stereo panning, so now, if you

pan that stereo piano track, say, all the way right, youll be hearing both the left

and right sides, in proper balance, in the right speaker, as youd expect when

mixing & panning stereo tracks.

Audio Example 1A simple figure from a piano with a wide stereo spread (high

notes left, low notes right): 2 Bars Centered; 2 bars Panned Hard Left with the

Balance knob (the low notes from the opposite side almost disappear); 2 Bars

Panned Hard Left with the Direction Mixer (the low & high notes are back in

balance):

But hard-panning (both L & R in mono) is reached at the -90 (left speaker) and

90 (right speaker) positions, not at the maximum left or right positions of the

knob. As you turn past -90/90, the image will return to centered full stereo,

but, at the full -180/180 positions, the left and right channels will be reversed

(left side of the track on the right, right side on the left).

As long as you know what to expect, the Direction Mixer gets the job done. It is a

little less convenient than having a true Stereo Panner right there in the Channel

Stripwhen you take a visual overview of your mix, you cant see, at a glance,

how stereo tracks are panned without opening up a bunch of Direct Mixer plug-

in windowsbut, other than that minor inconvenience, you do have full-

function, true stereo panning.

The LR and MS buttons just let you select the correct setting for normal stereo

recordings vs MS (Mid-Side) recordings. The Direction Mixer also has a

Spread slider, which widens or narrows the stereo signal: 1.00 is normal

Stereo; lower settings gradually narrow the image, with 0.00 being Mono; and

settings above 1.00 widen the image. This spreading can get a little diffuseits

more of a special effect, that might work better with sounds like strings and

padsand, even though it seems ok, youll always want to check mono

compatibility when using widening effects like this.

Audio Example 2 The Direction Mixers Spread slider in action: Normal Stereo

(1.00); to Mono (0.00); to enhanced stereo (2.00); back to 1.00:

The Law of the Pan

Theres another aspect to Panning in Logic that you should be be familiar with:

Pan Law. Pan law is a preference (actually, a per-song Project Setting here) that

governs how the apparent level is affected when panning. When you pan a track

to the center, its coming out of both speakers (equally). But if you pan it to

either side, its only in one speaker. As you might expect, with only one physical

sound source, the level youll hear is somewhere between 2-6 dB lower than the

level you hear from the centered track (theres no exact number here, due to

variations in acoustics)most people have settled on 3 dB as the typical amount.

This is no big deal, if you panned something and the level dropped, you could

just compensate with the channel fader, but in a busy mix with very precise track

levels or lots of volume automation, experimenting with pan position could be

inconvenient, unintentionally making slight, but possibly problematic, changes

to the mix balance. Pan Lawwhich youll find under File Menu->Project

Settings->Audiocan compensate for this. With it off, youll observe the

behavior I just described. Switch it on, and the level will be unchanged as you

pan left or right, eliminating any potential nuisance issues. Two choices let you

decide exactly how this is accomplished: -3 dB reduces the level of the track (by

3 dB, of course) when its panned center, and gradually increases it (back to

Unity Gain) as you pan to the sidesthis is a typical application in the industry;

-3dB Compensated leaves the tracks level at Unity Gain when the Pan knob is

centered, instead raising the level up to 3 dB as you pan to the left or right.

Fig 4 The

Pan Law options (in Logics Project Settings).

With identical Channel Fader levels, both -3 dB Pan Laws will give you the exact

same mix, but the overall level will be 3 dB higher with the Compensated option.

The gotcha can happen if you switch between either and no Pan Law (the 0 dB

option)then the balance between centered tracks and panned tracks will

change slightly, depending on how wide the pan settings are. Thats why Logic

makes it a per-song Project Setting rather than a global Preference.

So, which Pan law is best? Most people would choose a -3 dB option (its the

default in most DAWs, including Logic), but Compensated or not? Well, if your

individual track levels tend to run hot, up near the top of the meters, then -3 dB

might be best for you. If you pan to one side with -3 dB Compensated, the level

of that channel will increase by up to 3 dB, which, could potentially take you into

the red (I know thats not such a big deal with modern DAWs, but its still not

good practice). Personally, I do use -3 dB Compensated, and have no problems.

Spread It Around

Since I mentioned the Direction Mixers Spread control, theres one more

Imaging plug-in I also want to mention. We all know there are various ways to

generate a stereo image from a mono one, like stereo doubling with wide

panning, and phase-based processing tricks (which can be iffy, since the signal

may cancel or sound nasal & thin if heard in mono).

Logic provides a safe way to create a nice stereo image from a mono sourcethe

Stereo Spread plug-in. This splits a signal into left & right, and then divides each

side into several identical EQ bands. Complementary boosts & cuts are applied

to the two sidesso, if Left is boosted at, say 500 Hz, 2k and 8k, Right will be cut

at those frequencies, and if Right is boosted at 1k and 4k, then Left will be cut at

those frequencies, etc.. When heard in stereo, the signal will not be changed in

tone (thanks to the complementary boosts & cuts), but will take on a wider

image, thanks to the differences between channels. But if heard in mono, those

complementary EQ settings will cancel, leaving the signal untouched, with no

potential phase issues. It works pretty wellhave a listen to Audio Example 3.

Fig 5 Logics

Stereo Spread plug-in.

Audio Example 3 A mono String patch stereoized with the Stereo Spread plug:

These panning issues and plug-ins may not be as glamorous as many other cool

effects, but theyre important to get right, to make sure Logic isnt fighting you

when you sit down to mix. I hope this article helps...