Using the Mixer

While most mixing tasks can be accomplished in the Timeline and elsewhere in the Soundtrack Pro interface, the Mixer offers an interface analogous to hardware mixing consoles found in most audio post-production facilities. Another advantage of the Mixer is that you can view levels on all (or at least many) tracks simultaneously in real time.

Figure. Mixer tab.

The Mixer features a series of vertically arranged controls called channel strips, like the channel strips in a hardware mixing console. The channel strips in the Mixer correspond to the horizontal tracks, busses, and submixes in the project Timeline.

Figure. Channel strip.

The controls a channel strip contains depend on whether it is a track, bus, or submix channel strip. The controls for each type are as follows:

Track channel strips
Bus channel strips
Submix channel strips
Color label
Color label
Color label
Icon
Icon
Icon
Effects slots
Effects slots
Effects slots
Output pop-up menu
Output pop-up menu
Output pop-up menu
Panners (stereo or surround)
Panners (stereo or surround)
Volume fader and value slider
Volume fader and value slider
Volume fader and value slider
Level meters with peak indicator
Level meters with peak indicator
Level meters with peak indicator
Arm for Recording button
Mute button
Mute button
Mute button
Solo button
Solo button
Solo button
Name
Name
Name

The channel strips in the Mixer make it easy to see the settings for all the tracks, busses, and submixes in your project at once and to adjust those settings relative to each other as you create the overall mix.

In the Mixer, the channel strips appear in order corresponding to their order in the Timeline. Top-to-bottom order in the Timeline corresponds to left-to-right order in the Mixer. You can reorder tracks in the Mixer and have the new order reflected in the Timeline. Changes you make to controls such as volume and pan also show up in the track controls when you open the project in the Timeline.

Using Custom Layouts for Mixing

You can rearrange the Soundtrack Pro layout to suit your particular mixing workflow. There are numerous possible combinations. You can tear off tabs and have them float over the Soundtrack Pro window or show them on a second display. One default layout (in addition to the standard layout) floats the Mixer and the Video tabs as separate windows. This allows you to further resize the Mixer and the Video windows to an arrangement that is convenient for mixing.

To display the Mixer and Video tabs as separate windows
Do one of the following:
  • Choose Window > Layouts > Separate Mixer and Video (or press F2).

  • Using the pointer, drag the Mixer and Video tabs out of their docked positions.

    The Mixer and the Video tabs float over the Soundtrack Pro window as separate windows.

Another useful layout to consider is one showing just the Timeline and the Mixer. This arrangement is convenient for visually positioning the playhead during a mix.

Figure. Multitrack Timeline window showing Timeline and Mixer.

Once you have resized or moved the windows to a comfortable arrangement, you can save the layout as a custom layout for future use. For information about saving custom layouts, see Using Project Layouts.

Adding Channel Strips to the Mixer

You can add a channel strip for a track, bus, or submix in the Mixer in the same way you add a track, bus, or submix in the Timeline.

To add a track channel strip
  • Choose Multitrack > Add Track.

To add a bus channel strip
  • Choose Multitrack > Add Bus.

To add an output channel strip
  • Choose Multitrack > Add Output.

Selecting Channel Strips

You can select a channel strip in order to move, copy, or remove it. Selected channel strips appear darker in the Mixer.

To select a channel strip
  • Click any empty part of the channel strip.

You can select multiple channel strips in the Mixer.

To select adjacent channel strips
  • Shift-click the channel strips you want to select.

To select nonadjacent channel strips
  • Command-click the channel strips you want to select.

Reordering Channel Strips

You can change the order of channel strips in the Mixer. When you open the Mixer, the order of channel strips corresponds to the order of tracks, busses, and submixes in the Timeline. Because channel strips are oriented horizontally in the Mixer, top-to-bottom order in the Timeline corresponds to left-to-right order in the Mixer. Reordering channel strips in the Mixer also changes their order in the Timeline.

In the Mixer, as in the Timeline, channel strips of the same type (track, bus, or submix) are grouped together. You can reorder a channel strip within its own group, but cannot move it to a group of a different type. You can only move one channel strip at a time.

To reorder a channel strip
  • Drag the channel strip left or right to a new position.

Copying Channel Strips

You can copy channel strips in the Mixer. You can copy a channel strip within its own group, but cannot copy it to a group of a different type. You can only copy one channel strip at a time.

To copy a channel strip
  • Option-click the channel strip, then drag it left or right.

A copy of the channel strip appears when you release the mouse button.

Setting Channel Strip Volume Levels

You set relative volume levels to balance the various parts of the project. You set the volume level of a channel strip using the channel strip volume fader or value slider.

Different sounds can have different apparent loudness at the same volume level, so perceived loudness does not precisely correspond to numeric values on the volume faders. You determine the appropriate volume level by listening to the track and adjusting its level in the overall mix.

To set the volume level of a channel strip
Do one of the following:
  • Drag the volume fader up to raise (increase) the volume, or drag it down to lower (decrease) the volume.

  • Click along the length of the volume fader at the point you want to set the volume level.

  • Click the left or right arrows on the edges of the volume value slider.

  • With the pointer over the center of the volume value slider, hold down the mouse button and drag left or right.

  • Click the center of the volume value slider, then type a new value.

    The scale is from -96 to +6 dB. The default level is 0 (zero) dB.

    Figure. Channel strip, showing volume fader and volume value slider.
To return the volume fader to the default level
  • Double-click the knob in the volume fader.

As you adjust track volume, watch the level meters next to the volume fader to make sure that the track is not clipping. For information about preventing clipping, see Setting the Overall Project Volume Level.

Setting Channel Strip Pan Position

You pan sounds to different positions to place them in the stereo or the surround field. You set the pan position of a track or bus channel strip using the stereo pan slider and value slider or the surround panner. You can’t pan a submix or the Master channel strip.

To set the stereo pan position of a channel strip
Do one of the following:
  • Drag the pan slider left or right to the pan position you want.

  • Click along the length of the pan slider at the point you want to set the pan position.

  • Click the left or right arrow on the edges of the pan value slider.

  • With the pointer over the center of the pan value slider, hold down the mouse button and drag left or right.

  • Click the center of the pan value slider, then type a new value.

    The scale is from -100 to 100, with 0 (zero) as the center value. Negative values are left of center, and positive values are right of center. The default is 0.

    Figure. Channel strip showing pan slider and pan value slider.
To return the stereo pan slider to the default level
Do one of the following:
  • Control-click the slider, then choose Set to Centered from the shortcut menu.

  • Double-click the knob in the stereo pan slider.

To switch the panning controls from stereo to surround in the channel strip
Do one of the following:
  • Select a channel strip in the Mixer, then choose Multitrack > Use Surround Panner.

  • Control-click the stereo pan slider, then choose Use Surround Panner from the shortcut menu.

    Figure. Channel strip showing Surround Panner.
To set the surround pan position of a channel strip
  • Drag anywhere inside the black circle to position the puck.

To return the surround panner to the default level
  • Control-click the panner, then choose Set to Centered from the shortcut menu.

For finer surround panning adjustments and other surround controls, double-click the surround panner to open the Surround Panner HUD. For more information, see Using Surround Panners to Create a Surround Mix and The Surround Panner HUD.

Setting Channel Strip Output

On a hardware mixing console, you can send signals to different busses and physical outputs. You can create submixes and busses in Soundtrack Pro, assign tracks and busses to different submixes, and assign submixes to physical output channels on connected audio devices. You can send audio from as many tracks and busses to the same output as you want.

To set the submix for a track or bus
  • Choose the submix from the Submix pop-up menu at the bottom of the channel strip for the track or bus.

    Figure. Channel strip showing Submix pop-up menu.

For submixes in the Mixer, the Output pop-up menu lists the available output channels.

To set the output for a submix in the Mixer
  • In the channel strip for the submix, choose the output channel or set of channels from the Output pop-up menu.

    Figure. Channel strip showing Output pop-up menu.

    The options listed in the Output pop-up menu depend on the number of available physical outputs and the number of submixes in your project. For more information about setting the output, see Setting Hardware Outputs.

    Note: You can create submixes independently of the audio hardware connected to your computer and can route audio to an output that does not correspond to a physical output. In most situations, each submix in a project should correspond to a physical output on the audio interface or other hardware connected to your computer. Submixes that do not correspond to a physical output will not be heard. You may set as many submixes in a project to the same physical output device or output channel as you like.

To select an audio interface as the output device
  • Choose Apple menu > System Preferences, click Sound, then click the Output button. Select the audio interface in the list that appears.

    For more information about these settings, see Setting the Audio Input and Output.

Muting and Soloing Channel Strips

You can mute and solo channel strips in the Mixer in order to hear or silence specific tracks, busses, or submixes.

Figure. Channel strip showing Arm for Recording button, Mute button, Solo button, and Bypass Effects button.
To mute a channel strip
  • Click the channel strip’s Mute button. Click the button again to unmute the channel strip.

To solo a channel strip
  • Click the channel strip’s Solo button. Click the button again to unsolo the channel strip.

To exclusively solo a channel strip
  • Option-click the Solo button. Click the Solo button again to unsolo the track, bus, or submix.

When you export a project, all unmuted tracks, busses, and submixes are included in the exported file. If you export a track, bus, or submix that is muted (including being muted by having another track soloed), the exported file contains no audio.

Enabling Track Channel Strips for Recording

You can enable a track channel strip for recording. When you enable a track channel strip for recording, audio will be recorded on the track when you click the Record button in the transport controls. You can’t record to a bus or output channel strip.

To enable a track channel strip for recording
  • Click the Arm for Recording button in the channel strip. Click the button again to disable the channel strip for recording.

    You can record only to a track, not to a bus or an output.

Renaming Channel Strips

You can rename a channel strip to help you remember its content or purpose in the overall mix.

To rename a channel strip
  • Click the channel strip’s name (at the top of the channel strip) to select it, then type a new name.

Changing a Channel Strip Icon

You can change the icon of a channel strip. Icons do not affect the sound, but are useful as a quick visual reference for the channel strip, particularly for projects with many tracks, busses, or submixes.

To change a channel strip icon
  • Double-click the icon you want to change, then choose a new icon from the icon menu.

    Figure. Channel strip showing a typical channel strip icon.
    Figure. Channel strip icon menu.

Showing and Hiding Sections of the Mixer

You can show or hide sections of the Mixer window and sections of channel strips. Hiding sections of the Mixer and the channel strips can be helpful, especially when using Soundtrack Pro with a smaller computer display or when working on projects with a large number of tracks, busses, or submixes.

You can show or hide any of the following sections of the Mixer:

  • Audio tracks

  • Busses

  • Submixes

To hide a section of the Mixer
  • Choose the section you want to hide from the Show pop-up menu, located at the upper right of the Mixer.

    Figure. Mixer tab showing Channel Strip pop-up menu and Show pop-up menu.
To hide sections of channel strips
  • Choose the section you want to hide from the Channel Strip pop-up menu.

    The visible sections of the channel strips appear with a checkmark in the Channel Strips pop-up menu. You can show or hide any of the following sections of the channel strips:

    • Icons

    • Effects slots

    • Output pop-up menus

    • Pan controls

    • Volume faders and level meters

Using the Channel Strip Level Meters

Each channel strip includes level meters to the left of its volume fader. You can use the level meters to observe each channel strip’s level as the project plays. The level meters range from -96 dB to +6 dB, moving from bottom to top as the level increases. The segments of the level meters run from green through yellow to orange as the level increases.

Note: For surround signals, the channel strip meters show the signals in this order: Ls, L, C, R, Rs, LFE. This matches the surround order in the Meters tab. (See Setting the Overall Project Volume Level for more information.)

At the top of each set of level meters is a peak indicator. As the project plays, the value in decibels of the highest level reached appears in the peak indicator. If the level rises above 0 dB, the peak indicator becomes red. The values shown in each peak indicator remain until you play the project again, close the project, or reset the peak indicator.

Figure. Channel strip level meter showing peak indicator and level meters.
To reset a peak indicator
  • Click the peak indicator.

To reset all peak indicators
Do one of the following:
  • Option-click the peak indicator in any channel.

  • Click the Reset button in the Meters tab.

The peak indicators can help identify where clipping occurs in the project. For information about removing clipping, see Setting the Overall Project Volume Level.

Removing Channel Strips

You can remove a channel strip from the Mixer if you decide you no longer want it in the project.

To remove a channel strip
Do one of the following:
  • Select the channel strip, then choose Multitrack > Remove [item].

  • Control-click the channel strip, then choose Remove [item] from the shortcut menu.

    The term indicated by [item] changes in the menu depending on whether a track, bus, or submix is selected.

Note: If audio from a track is sent to a bus or output, and you remove the bus or output, the audio from the track will not be heard when you play the project.

Working with Effects in the Mixer

You can add effects to a channel strip in the Mixer, show effects settings, turn effects on and off, replace an effect, and delete effects. You can also adjust effects settings in the Effects tab or in the effect’s advanced settings window.

Adding Effects to a Channel Strip

You can add effects, turn effects off and on, and reorder effects in a channel strip.

Note: Before adding an effect to a track, it’s a good idea to solo the track so that you can hear how the effect changes its sound, separate from the other tracks in the project.

To add an effect to a channel strip
  • Control-click an empty effects slot in the channel strip, choose Add Effect from the shortcut menu, then choose one of the available effects from the categories in the submenu.

    Figure. Channel strip Add Effect shortcut menu.

Showing Channel Strip Effects Settings

Once you add an effect, you can view and adjust its settings in the Effects tab.

To show an effect’s settings in the Effects tab
  • In the channel strip, Control-click the effect, then choose Show [effect name] Settings from the shortcut menu.

    The Effects tab becomes active, and shows the selected effect’s settings.

Some effects have a floating advanced settings window with sliders and other controls you can use to adjust effect parameters.

To show advanced settings for an effect
Do one of the following:
  • Double-click the effect name in the channel strip.

  • Control-click the effect, then choose Show [effect name] Advanced Settings from the shortcut menu.

    The effect’s advanced settings window appears.

    For information on working in the advanced settings window, see Automating Realtime Effect Parameters.

Reordering Effects in the Mixer

You can reorder effects in the Mixer as well as in the Effects tab. When you reorder effects, you change the order in which the audio is processed by each effect, which can change the sound drastically.

To reorder an effect in the Mixer
  • Drag the effect up or down in the effects slot area to change its order.

Turning Effects Off and On

You can turn off a channel strip’s effects. Turning off an effect lets you hear the channel strip without the effect, while preserving the current effects settings.

To turn off an effect in a channel strip
Do one of the following:
  • Deselect the checkbox to the left of the effect name.

  • Control-click the effect, then choose Disable [effect name] from the shortcut menu.

To turn off all effects in a channel strip
  • Control-click an effects slot, then choose Disable All Effects from the shortcut menu.

To turn on an effect again
Do one of the following:
  • Select the checkbox to the left of the effect name.

  • Control-click the effect, then choose Enable [effect name] from the shortcut menu.

To turn on all effects in a channel strip
  • Control-click an effects slot, then choose Enable All Effects from the shortcut menu.

Replacing an Effect

You can replace an effect in a channel strip with another effect. When you replace an effect with another effect, the new effect has its own default settings, regardless of the settings of the previous effect.

To replace an effect in a channel strip
  • Control-click the effect, choose Replace [effect name] from the shortcut menu, then choose a new effect from the submenu.

Deleting Effects from a Channel Strip

You can delete an effect if you decide you don’t want to use it in a channel strip. You can also delete all effects from a channel strip.

To delete an effect from a channel strip
Do one of the following:
  • Select the effect, then choose Edit > Delete (or press the Delete key.)

  • Control-click the effect, then choose Delete [effect name] from the shortcut menu.

To delete all effects from a channel strip
  • Control-click an effects slot, then choose Delete All Effects from the shortcut menu.

For more information about working with effects, including information on uses of different effects and adjusting effect parameters, see Working with Audio Effects.

Working with Sends and Busses in the Mixer

This section covers using sends in Mixer channel strips. For more general information about sends and busses, see Using Sends and Busses and Adding Sends to Tracks.

Adding Sends to a Channel Strip

You can add sends to a channel strip, show send settings in the Effects tab, bypass a send, or remove a send in the Mixer.

To add a send to a channel strip
  • Control-click an empty effects slot in the channel strip, choose Add Send from the shortcut menu, then choose one of the available busses in the submenu.

The new send is added. When you add a send, the audio is routed from the send to a bus. By default, the first send you add to an effects chain is routed to Bus 1, the second send is routed to Bus 2, and so on, if the default bus exists. You can choose the bus to which a send is routed.

By default, new sends are post-fader sends. You can change a send to a pre-fader send.

To make a send a pre-fader send
  • Click the disclosure triangle for the send in the Effects tab, then select the On button next to Pre-Fader.

Reordering Sends in the Mixer

You can reorder sends in the Mixer as well as in the Effects tab. When you reorder sends, you change which effects are routed to the send, which can change the sound drastically.

To reorder a send in the Mixer
  • Drag the send up or down in the effects slot area to change its order.

Showing Send Settings

You can show the settings for a send in the Effects tab. Send settings include volume, pan, and the bus to which the send is routed.

To show settings for a send
  • In the Mixer, Control-click the send, then choose Show Send Settings from the shortcut menu.

    The Effects tab becomes active, with the settings for the send visible in the Effect Parameters area.

Turning Sends Off and On

You can turn sends off, and turn them back on. When you turn off a send, the audio is not routed to the send bus, and is not heard.

To turn off a send in a channel strip
Do one of the following:
  • Deselect the checkbox to the left of the send name.

  • Control-click the send, then choose Disable Send from the shortcut menu.

To turn on an effect again
  • Select the checkbox to the left of the effect name.

Setting the Overall Project Volume Level

As you finalize a project mix, you set the overall project volume to the appropriate level. Certain formats or methods of distribution may require that the project conform to a particular maximum level. In general, you set the overall volume of the project to the highest level at which no clipping occurs at any point in the project.

Clipping occurs when the digital audio signal exceeds the maximum level that can be reproduced accurately. Unlike analog audio, digital audio is completely unforgiving of clipping, which creates sharp distortion of the audio signal. Soundtrack Pro projects clip whenever the output displayed in the level meters exceeds zero decibels (0 dB). It’s important to eliminate clipping from projects before exporting the final mix. For more information about digital distortion, see Audio Fundamentals.

You can monitor audio output levels using the level meters in the Mixer, the Meters tab, and in individual track headers. In the Mixer, each channel strip has level meters that show the levels for that channel strip. In the Meters tab, the level meters show the levels for all submixes assigned to physical output channels. For more information about setting up physical outputs, see Setting the Audio Input and Output.

The Meters tab includes additional controls and displays to help you maintain proper audio levels and eliminate clipping.

Figure. Meters tab showing 2-channel meter and level meters and Meters tab showing 6-channel meter and Reset button and Peak value and Location display.

As a project plays back, the levels in each channel change constantly with the rising and falling of the audio signal. The level meters show these changes both as bars rising to varying heights and as changes in color from green to yellow.

In each channel’s meter, a white horizontal bar displays the current signal level; bars below the white bar display successive levels in a scale that rises from green to yellow as the signal increases. The meters peak at red when the signal clips (rises above 0 dB).

Note: The meters can be configured via Soundtrack Pro preferences to display either surround order (Ls, L, C, R, Rs, LFE) or output order (channels 1-n). To change this setting, choose Soundtrack Pro > Preferences > General.

To change the channel order in the meter display
  1. Choose Soundtrack Pro > Preferences.

  2. Select the General pane.

  3. In the Timeline section, select your preferred channel display order from the Meters Channel Display pop-up menu.

    For more information about Soundtrack Pro preferences, see Soundtrack Pro Preferences.

Using the Peak Indicators in the Mixer Channel Strips

At the top of the level meters in the Mixer channel strips is a rectangular peak indicator that lights red when that channel clips (exceeds 0 dB). The peak indicators are “sticky,” meaning that if clipping occurs in either channel, the peak indicator lights red and stays red until you reset it, or reset all peak indicators.

To reset a peak indicator
  • Click the peak indicator.

To reset all peak indicators
  • Option-click any peak indicator in any of the Mixer level meters.

Using the Peaks Value and Location Display in the Meters Tab

The Peaks Value and Location display in the Meters tab displays the highest (peak) value played in each output channel in decibels (dB) and its timecode. The Time column shows the location in the Timeline where the peak occurs. You can use the Peaks Value and Location display to quickly locate a section of your project that is clipping or peaking.

To move the playhead to the highest (peak) value played in a channel
  • Double-click any item in the Peaks Value and Location display.

    The playhead moves to the corresponding point in the Timeline.

The Reset button located in the upper-right corner of the Meters tab display resets the Peaks Value and Location display to a minimum value (-96 dB) and resets the Time column to the beginning of the project.

To reset the Peaks Value and Location display values
  • Click the Reset button.

Using the Master Bus

The Master bus represents the final mix from Soundtrack Pro—what will be heard from the physical output jacks. On a signal routing basis, the Master bus is practically a mirror image of the connected hardware output device. It is as wide as either the hardware device or the number of channels used in the project, whichever number is smaller.

Master Bus Details

The Master bus includes envelopes for volume, transposition, and tempo. By default, only the Volume envelope is visible. For more information, see Master Bus. The Master bus does not have panners or meters.

You can apply effects to the Master bus, but you cannot automate those effects. Effects applied to the Master bus are placed across all channels. You can bypass effects on the Master bus. For more information about bypassing effects, see Bypassing Realtime Effects.

Adjusting the Master Volume

The steps you take to remove clipping depend on the cause of the clipping. You can lower the master volume of a project by the amount the highest point in the project (as shown in the Value display) exceeds 0 dB. You can also use the Go buttons to locate where clipping occurs and use a different audio clip or lower the volume of individual tracks until clipping no longer occurs. Sometimes adjusting the gain on effects can remove occurrences of clipping as well.

Listening to a Temporary Mono Mix

In some situations, even where the final mix is stereo, you may want to listen to the mix in mono as well as stereo. If the final project is likely to be viewed using equipment with mono audio output (for example, many television sets have mono output), you may want to make sure the mix is suitable for mono output. Listening to a mono mix can also help identify phase issues that can occur when a stereo project is played in mono. Soundtrack Pro makes it easy to listen to a temporary mono mix of the project so you can hear how it will sound in mono.

To listen to a temporary mono mix
  1. Start the project playing.

  2. While the project plays, press and hold the Mono Mix button, located to the right of the Monitor volume slider below the Mixer.

    Figure. Mono Mix button.

    The Mono Mix button becomes darker to indicate that it is active. When you are finished listening to the temporary mono mix, release the button to hear the project mix.

In addition to listening to a temporary mono mix by holding down the Mono Mix button, you can “latch” the Mono Mix button. This keeps the mono mix active until you click the button again or switch to a different project.

To latch the Mono Mix button
  • Option-click the Mono Mix button.

Recording Audio in the Mixer

You can record audio while working in the Mixer. When you record audio in the Mixer, recording starts from the current playhead position. Although the playhead is not visible in the Mixer, you can set the playhead position using the transport controls or the Playhead Location value slider located at the bottom of the Soundtrack Pro window.

For more information about recording, see Recording Audio in Soundtrack Pro.

Recording Automation in the Mixer

You can record automation for volume and pan changes in the Mixer. You record automation in the Mixer by choosing either Touch or Latch automation mode in the project controls, then changing volume or pan settings as the project plays. You can record automation either using the onscreen volume and pan controls, or using a control surface connected to your computer.

For more information about working with automation, see Working with Automation.

Creating Multiple Mixes

You might want to create multiple mixes of a project for one of the following reasons:

  • To optimize the project for different playback situations

  • To try out different settings of the various track and master controls using the same arrangement

  • To try out changes to the arrangement using the same basic material

You can easily create multiple mixes by giving the project a slightly different name when you save each mix, or by using different combinations of tracks, busses, and submixes for each mix. If you are saving the project and its media files together, the different versions can be saved to the same location if they all use the same media files. For information about saving projects and their media files together, see Saving Multitrack Projects.

Things to Keep in Mind While Mixing

The following are intended as guidelines or suggestions to follow when mixing your projects, not as “hard-and-fast” instructions.

  • Consider the importance of each element in the overall mix.

  • Keep related tracks close together (in the Timeline and the Mixer).

  • Don’t create a final mix until the picture is locked.

  • Listen to the mix with the best possible equipment.

  • Also listen to the mix as the audience will hear it.

  • Don’t change output/monitor levels while mixing.

  • Mix by what you hear, not by what you see.