Partially or Entirely Missing Audio Output


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."

Background

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.

Solution

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.

  • With the manual method, you use the audio and video playback options in the View menu to match audio to video explicitly. For example, choose View > Audio Playback > FireWire DV to route the audio from a DV sequence to match a setting of View > Video Playback > Apple FireWire NTSC (or PAL or DVCPRO) for video.

  • With the automatic method, you first select the proper output for video and then choose View > Audio Playback > Audio Follows Video. That setting will always override the current Audio Playback setting and automatically route it to wherever the video output is being sent.

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."

Background

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.

Solution

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:

  1. Choose Final Cut Pro > User Preferences > Audio Outputs tab.

  2. Click the Duplicate button to get to the Audio Outputs Preset Editor.

    The Audio Outputs Preset Editor is a template used to create new presets for use with your multichannel output device.

  3. After typing a name and description for the preset, click the Outputs pop-up menu to select the number of outputs your device has.

    When you do so, you will get several pairs of potential tracksfor example, six outputs yields three pairs. Each output pair contains a Stereo or Dual Mono switch and a pop-up control for adding downmix (dB) level reduction. The choice between dual mono or stereo grouping depends on the type of work you are doing.

    Downmix level control can be important, particularly when you send similar or identical mono audio tracks through two grouped channels. Because of the way that audio waves interact, this can lead to a situation in which the audio channels either double the level of audio by being grouped together or cancel each other out if they are thrown slightly out of phase.

    In general, stereo audio equipment will eliminate such wave interference, but that isn't guaranteed. If your audio levels boost or diminish unexpectedly after you create a new preset, you may need to try subtracting or adding downmix levels.

  4. Click OK to create the preset and then OK to leave User Preferences.

    Next, you need to choose the output device to which FCP should apply the multichannel audio preset.

  5. Choose Final Cut Pro > Audio/Video Settings.

  6. In the subsequent dialog, click the A/V Devices tab, choose the output device you want to monitor with, and click OK.

  7. With the sequence active in the Timeline window, choose Sequence > Sequence Settings.

  8. On the Audio Outputs tab, click the Presets pop-up menu, and choose the multichannel preset you created in steps 14.

  9. Finally, Ctrl-click each audio track in the sequence (right around the Autoselect track toggle), and route it to a dedicated audio output track in the contextual menu.

    Note that if you chose Stereo grouping in the preset, Ctrl-clicking the track gives you the option of choosing a pair, whereas with Dual Mono, you can route any track to any output channel.



Apple Pro Training Series. Optimizing Your Final Cut Pro System. A Technical Guide to Real-World Post-Production
Apple Pro Training Series. Optimizing Your Final Cut Pro System. A Technical Guide to Real-World Post-Production
ISBN: N/A
EAN: N/A
Year: 2004
Pages: 205

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