Symptom #1: Audio Is Missing or Coming Out of Incorrect Output Device
"I've got video coming out of the right output device, but there is no audio."
"Audio is coming out of the wrong output device."
"Audio is coming out of the Macintosh."
FCP can output audio to a different output device than the video. This can be a great option if you are using a professional audio interface for your project. You might be sending the video signal to a FireWire DV device or capture card, for example, but sending all eight tracks of audio out discretely to an eight-track ADAT setup or other multichannel recording system.
Having this ability means you have to be more careful with your settings than you previously were to prevent unintentional separation of your audio and video.
Choose Sequence > Sequence Settings, and verify your audio settings in the General tab. For example, make sure the sample rate and bit depth are appropriate for your device. It's also important to check the number of outputs selected in the Audio Outputs tab.
In general, there are two ways to match your audio output to your video output: the manual method and the automatic method.
Another setting to check if your audio and video still aren't matching up is the Sound system preference. If you want your audio to be routed through your Macintosh's onboard audio resources (built-in audio or third-party PCI or USB audio devices) rather than being sent to a specific output device, like a DV deck, you may need to choose the device in the Sound system preference as well as FCP.
Symptom #2: FCP Won't Output More Than Two Channels of Audio at a Time
"I have an output device that handles more than two channels of audio at a time, but my FCP tracks mix down to only two of the output device's tracks."
Although FCP always had the ability to work with up to 99 tracks of audio in a sequence, you were limited to 2 channels of audio output and capture at a time, due to limitations in the QuickTime architecture. FCP can now handle up to eight channels, depending on the device you are using.
If you have an audio interface that supports more than two channels of audio output at a time, you can create audio presets that route your sequence audio tracks directly out to specific channels of the audio output device. In general, this requires a device that has CoreAudio driver support, enabling both QuickTime and FCP to recognize it as a legitimate output device.
If you don't explicitly create multichannel audio presets, however, FCP will use its default Audio Output preset for standard two-channel stereopotentially creating confusion for you if you don't know about this default.
To enable FCP's multichannel audio output capability, you need to create an audio preset for the number of channels your output device supports, as follows: