Working with music in surround sound is new to almost everyone, even veteran musicians, producers, and engineers. There are no rights and wrongs at this point. The picture you paint with a surround mix can be much more varied than with stereo. Do you create the illusion that the listener is watching a band that's up on a stage, or do you put the listener on the stage, in the middle of it all? Now that you know what the controls do, it's time to experiment with them. For this section, there is no formal exercisesimply play with your newfound surround toy and see what happens.
Filtering the LFE
Before bouncing your final mix, it's a good idea to remove frequencies higher than what your subwoofer can produce. The signal being sent to the LFE goes over a full-frequency channel, but the frequency response of the subwoofer generally limits what you hear to a low rumble. However, in some consumer 5.1 playback systems, users can indicate in their equipment configuration options that a subwoofer is not present, causing the LFE channel to be redirected into the main speakerswhich means the full-range signal of the LFE channel is heard through the main speakers. If that occurs with your song, the consumer will hear a mix that you never intended, and this could be quite disruptive to the overall sound of your song. By filtering the LFE output in Logic before bouncing, you eliminate any possibility that the full-range signal of the LFE will be heardregardless of a consumer's configuration.
So, let's go ahead and filter the LFE on your song's output.
Adjusting the Surround Mix Level
Currently, you have six Output Objects in the Environment. To raise or lower the volume of your surround mix, you need to raise or lower the volume of all six Output channels together, at the same time. You could group the channels and then adjust the volume, but there's an even slicker way. Logic provides a special Master Audio Object that controls the volume level of all outputs simultaneously.
When moving the output faders, select them all first, and then move one of them up or down. This links the faders temporarily to ensure that the relative fader positions remain the same.
Bouncing for Surround Sound
You've already learned in Lesson 1, "Exploring the Workspace," how to bounce a final mix when working in stereo. Bouncing in surround sound is basically the same thing, except you have to pay attention to more meters and change one simple setting.
At this point, the files you have are not capable of being heard by most consumers. They need to be encoded into a format that consumer playback systems understand, such as DTS or Dolby Digital. Logic does not have encoders built into it, but there are third-party programs that do. For example, Apple's DVD Studio Pro comes with a Dolby Digital encoder called A.Pack, which allows you to apply the 5.1 sound track you've created in Logic to your own DVD-Video discs! To learn more about A.Pack, check out Apple Pro Training Series: DVD Studio Pro 3, or visit macProVideo.com.