Select Items in the Default Work Unit.

See how the Items Actor-Mixer Output Bus is set to Master Audio Bus. Because this is set on the Actor-Mixer, it means that all contained objects have their outputs assigned to Master Audio Bus as well. In other words, imagine every sound object as a piece of audio equipment, with an audio cable that’s connected directly to an audio mixing console that is called Master Audio Bus. Unlike conventional audio mixing consoles, which are limited by the number of physical inputs they have, there is no practical limit to how many individual audio objects can be connected to a bus.

Now take a look at the Master Audio Bus in the Master-Mixer Hierarchy.

In the Master-Mixer Hierarchy, expand the Default Work Unit and then select the Master Audio Bus.

In the Audio Bus Property Editor, you see an audio meter. Meters are something that aren’t available in Actor-Mixers because no audio actually passes through an Actor-Mixer. Since the actual audio level metering is found on an audio bus, this confirms that audio in fact passes through the object.

Select any Sound SFX object in the Actor-Mixer Hierarchy, and then re-select the Master Audio Bus and play your object.

The meters display the overall sound level feeding the bus.

	If you have Wwise set up for surround sound playback, you may see a different meter layout.

You may have noticed that there are two Volume controls. The Bus Volume control that also includes a volume fader represents the main master mix output. Adjusting this fader turns the summed signal coming from all sources feeding this bus up or down. The volume property as well as the Pitch and Low-pass filter properties found within the Voice do not act directly on the summed audio signal, but instead act as yet another set of offset controls which remotely impact any objects that are contributing to this bus. Because all objects ultimately feed the Master Audio Bus, adjusting any of these properties is like adjusting every single object in our project, so be very careful with these. A great way to see how this works is to re-visit the Voice Profiler layout you used in Lesson 3.

From the menu bar, choose Layouts > Voice Profiler or press F11.

Remember that the Voice Profiler does not display real-time information unless you start a capture session.

Click the Start Capture button.

In the Project Explorer, expand the Items Actor-Mixer, select the Teleporter Sound SFX object and press Play.

As the Teleporter sound plays, you can see it listed as an active voice in the Voice Explorer view.

In the Voice Explorer view, select Teleporter.

In the left pane of the Voice Inspector, you see a simple chart showing the audio signal flow indicating that the Teleporter's audio is routed to the Master Audio Bus. While this is true, the Items Actor-Mixer also plays a role when calculating the volume offset the Teleporter will play at. You can see all objects that will impact the calculated volume offset in the right pane of the Voice Inspector, which includes the Items Actor-Mixer. The "-" in the Volume column indicates that no offset is currently set.

In the Sound Property Editor, lower the Voice Volume to -6.

As you lower the volume, you hear the Teleporter get quieter. You also see in the Voice Inspector that the Teleporter Voice Volume is set to -6. At the top of the Volume column, you see a Final Value calculation, indicating that the total amount of volume offset is set to -6 dB. This Final Value will change as you modify the volume offset on other objects the Teleporter is impacted by. To make volume adjustments on other objects, you can double-click an object's row in the right pane of the Voice Inspector to see those settings in the Property Editor.

In the right pane of the Voice Inspector, double-click the Items row.

You see the Property Editor change to reflect the settings for the Items Actor-Mixer.

In the Property Editor, change the Items Actor-Mixer Volumeto -4.

You see the new offset value appear, including the Final Value showing a total of -10 dB.

Double-click the Master Audio Bus row.

As you learned earlier, the Master Audio Bus has two volume properties that can be adjusted.

Set the Master Audio Bus Voice Volume to -3 and the Bus Volume to -2.

Now you see the Final Value for the calculated offset come to -15 dB.

You can see in the left diagram that the Teleporter shows -13. This is because all of the values you entered except for the Bus Volume value are actually added together to impact what volume the Teleporter object should play at before being sent to the Master Audio Bus where the final adjustment of -2 dB is applied to the summation of all audio signals passing through the Master Audio Bus. With so many places having influence over if a sound plays at the proper level, you can appreciate the value of the Voice Profiler providing a way to reference all of these variables in a single place. Now that you understand how it works, we'll set all of the values you adjusted back to 0.

You can see that the Driver Column of the Voice Inspector displays Live Edit as you make changes. This is make it clear that what is being heard is based on changes you've made to the project since you began capturing, as opposed to if you were connected to the game itself. If you were to stop playback of the Teleporter and play it again, the column would display Project Value, indicating that the settings were part of the current project before starting the capture.

Reset all of the volume offsets you just made back to 0, stop playback of the Teleporter and stop capture.