Chapter 16: Mixing Your Project 281

Knowing Your Channel Strip Types

You use channel strips to shape your sound and control the signal flow. You have control over the volume, pan, effects, and where the sound is coming from and where it’s going. Similar to track types, which you learn about in Chapter 4, different channel strips do different things. Some channel strip types are automatically added to your project while others you can add for specific purposes.

In this section, you learn about the five different channel strips, which are shown in Figure 16-3, and what they do.

Figure 16-3:

The chan-

nel strips in

Logic Pro.

\ \

282 Part V: Mixing, Mastering, and Sharing Your Music

\		Show Advanced Tools must be selected in the Advanced Preferences pane to
		take full advantage of the mixer and all the information in this chapter. Choose
		Logic Pro X Preferences Advanced Tools, and then select Show Advanced
		Tools.

Audio channel strips

You use audio channel strips (refer to Figure 16-3) for audio tracks. When you create an audio track, an audio channel strip is automatically added to the mixer in your project. Everything you record live, such as guitars or vocals, uses an audio channel strip. Imported and bounced audio also use an audio channel strip.

Instrument channel strips

Software instrument tracks use instrument channel strips (refer to Figure 16-3). Instrument channel strips are similar to audio channel strips except that they use MIDI as the source material instead of audio. Instrument channel strips also allow you to add MIDI effects, which you learn about in the “Adding Effects to Tracks” section.

MIDI channel strips

MIDI channel strips (refer to Figure 16-3) are used to control your external MIDI gear. You can’t add audio or MIDI effects to these channel strips, and you can’t route audio or save channel strip settings. You can, however, control track automation, mute the track, and send general MIDI settings to the connected instrument, such as volume, pan, and other controller data.

Auxiliary channel strips

Auxiliary channel strips (labeled in Figure 16-3) are used mainly for routing the audio of other track types. You can use auxiliary channel strips as submixes and add effects as a whole. For example, all the tracks in a summing track stack (described in Chapter 4) send their audio outputs to a collective auxiliary channel strip. You can also send a portion of a track’s signal to an auxiliary channel strip via an effects send to blend reverbs, delays, or other effects with the track’s signal.

Chapter 16: Mixing Your Project 283

Output channel strips

All audio is routed through a default output channel strip (refer to the rightmost strip in Figure 16-3) before it goes to your master output. You can add effects to the output channel strip that will affect the entire mix, such as dynamics compression and EQ. If your hardware supports it, you can add additional outputs and assign tracks or submixes to them for outboard processing or additional monitor mixes.

\The inspector has two channel strips, as shown in Figure 16-4. The channel strip on the left shows the selected track’s channel strip. The channel strip

on the right is dynamic and, by default, shows the output of the channel strip on the left. If the selected track has a send effect, you can click the send slot and the second channel strip is updated to show the auxiliary channel strip being used to host the send effects. This feature is useful if you’re mixing a track and you also want to adjust the sound of the send effects it’s using.

Figure 16-4:

The inspector channel strips.

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284 Part V: Mixing, Mastering, and Sharing Your Music

Using Meters to Visualize

Volume and Levels

Loudness. We’re kidding ourselves that we can perceive it objectively. Music often sounds instantly better when it gets louder. But you can only turn it up so much before you see diminishing returns (or blow up your speakers). If you don’t stage your volume levels with the big picture in mind, you can

easily run into a situation where you’re constantly seeing red lights at the top of your meters and pulling down faders and readjusting the balance of your mix. In this section, you discover how to use your meters so you don’t trick yourself into thinking that louder is better.

\		If you calibrate your monitoring level as I described previously, in the
		“Frequency” section, you’ll have a much easier time perceiving loudness
		and you won’t need to rely on your meters to tell you how loud the music is.

Your ears are the number-one meter of quality. A little bit of ear training can go a long way in polishing your perception of sound. A close second to your ears are the meters on your channel strips. I’d like to give you one rule for setting the levels on your meters: Peak no higher than between –12 and –6 dBFS on your output channel strip. All the tracks that sum together will need to be even lower, probably between –18 and –12 dBFS. You will have plenty of opportunity to get your overall mix louder as you go through the mastering process in Chapter 18.

\	I have an hour-long video about ear training with Logic Pro X that I am
	happy to share with you. Just visit http://logicstudiotraining.com/
	lpxfordummies.

Understanding clipping

The meters in Logic Pro are measured in dBFS, which stands for decibel full scale. 0 dBFS is the top limit and anything above that is digital clipping. Digital clipping means that the signal has gone beyond maximum capacity.

The result is distortion in the audio, and not the good kind of distortion that rock guitar players know and love. Digital distortion is an unpleasant sound that you should avoid.

When digital audio came along, 16 bits was the maximum resolution. 16-bit audio accounted for about 96 dB of recordable space, and it was deemed important to record and mix as close to 0 dBFS as possible to keep noise low and use the full digital resolution. Logic Pro is capable of 24-bit recording, so you can record better signals at much lower levels and regain the headroom

Chapter 16: Mixing Your Project 285

that was a major benefit of analog mixes. In fact, you’d have to lower your mix by 48 dB to equal a 16-bit recording.

Lowering your mixing levels gives you more headroom and makes mixing easier because you’re not always fighting red lights (digital clipping) and having to readjust your balances. Lower mixing levels also makes it easier to work with third-party effects plug-ins or outboard analog gear and to raise the final level at the mastering stage.

Choosing pre-fader or post-fader metering

Audio professionals have a common complaint with Logic Pro’s meters: They default to post-fader. In post-fader metering, the position of the fader affects the level of the meters. With post-fader metering enabled, the meters will show no level if your channel strip fader is all the way down. Post-fader metering offers visual assistance when you’re using a “mix with your eyes” approach. You can see the track level with your eyes on the meter based on the location of your fader. That’s not a bad thing, but it’s definitely not the whole picture.

Switching to pre-fader metering shows you the level of the signal regardless of the fader’s location. Pre-fader metering allows you to see whether a track is clipping, even when your fader has pulled the level all the way down. You’d be surprised how many software instrument presets clip right from the start. You need to know exactly what signal level is hitting the channel so you can make the appropriate decisions when it comes to adding effects such as compression or EQ.

On analog mixing consoles, many engineers will set the faders to unity gain (the default position) and quickly get track levels stable by using a trim control. You can do something similar by putting Logic Pro’s Gain plug-in in the first insert effects slot, setting the basic rough level with the plug-in, and using the channel strip fader to fine-tune the level. You probably won’t need to add the Gain plug-in to every track, but it can help if a recorded track is too loud. You learn how to add insert effects later, in the “Adding audio and MIDI insert effects” section.

Another complaint is that peak level meters, the type Logic Pro and most digital audio workstations use, have almost nothing to do with loudness. For example, two takes from a drummer can sound equally as loud, but one take can peak 4–10 dB higher on a single snare hit. If you raise the other take so that they both peak at the same level, one will sound much louder, maybe even twice as loud. To judge loudness, the ear responds to average levels and not peak levels. Peak meters are great when you need to be concerned with clipping (well, you’re always concerned with that), but they don’t help you perceive loudness very well. For that reason, professionals often work with VU (volume units) meters, which more closely respond like an ear.

286 Part V: Mixing, Mastering, and Sharing Your Music

Logic Pro doesn’t come with VU metering, so learning to use pre-fader metering will help. Consider searching for a free VU meter plug-in or purchasing one. You can mix without VU meters, but the job is easier with them. To switch to pre-fader metering, follow these steps:

\1.\ Control-click an empty area of the control bar, and then choose

Customize Control Bar and Display.

\	The customization dialog opens.

\2.\ In the Modes and Functions column, select Pre Fader Metering.

\3.\ Click OK.

\\ The pre-fader metering icon (shown in the margin) is added to the con-

trol bar.

\4.\Click the pre-fader metering icon to turn it on.

\If you want to quickly switch between pre-fader and post-fader metering, set

the Toggle Pre-Fader Metering key command. For details, see Chapter 3.

Changing the level-meter scale

Take a look at your level meters, shown in Figure 16-5. The lower they are, the coarser they are. They go from increments of 1 dB at the top to 10 dB at the bottom. Trying to make subtle changes when your fader is near the bottom becomes more difficult than it needs to be. You can adjust the scale of your level meters to suit your needs.

Figure 16-5:

The channel strip level meter set to exponential scale.

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