Connecting Professional Audio Devices

The steps for connecting audio playback and recording devices are similar to the steps for connecting professional video devices. (For information on connecting professional video devices, see Connecting Professional Video Devices.) Many professional audio-only devices such as DAT recorders and Tascam DA-88/DA-98 multitracks also support remote device control and audio insert editing.

If you plan to capture footage using separate video and audio interfaces, you may need to set up additional synchronization between your audio device and audio interface. For more information, see Synchronizing Equipment with a Blackburst Generator as well as the documentation that came with your audio interface.

Connecting Professional Digital Audio Devices

Professional digital audio devices often use balanced XLR connectors. Each XLR carries two AES/EBU digital audio channels. Connect the digital audio outputs of your video or audio device to your audio interface (or its breakout box). If your video interface has the appropriate connectors, you can also connect the audio outputs of your device to the audio inputs on the video interface.

Note: Professional analog audio devices also use XLR connectors, but the signal is incompatible with AES/EBU digital audio.

Connecting Consumer Digital Audio Devices

Consumer devices such as CD players, MiniDisc recorders, and some DAT recorders use either an optical or RCA (coax) connector for S/PDIF digital audio. S/PDIF carries two channels of digital audio, usually at a sample rate of 44.1 or 48 kHz and a bit depth of 16 bits. Connect the S/PDIF output of your audio device to the S/PDIF input on your audio or video interface, if available.

Connecting Professional Analog Audio

Professional analog audio devices use balanced XLR or 1/4" TRS connectors for each audio channel. Most audio interfaces that support multiple audio channels come with a breakout box that contains all the connectors.

To connect multiple analog audio channels from a VTR or audio device to a multichannel audio interface
  • Connect each audio output channel on the VTR or audio device to each audio input channel on the audio interface or corresponding breakout box, if included.

A Recommended Audio System Using a Third-Party Audio Interface

To set up a system using a third-party audio interface, you need the following equipment:

  • Your computer and display

  • A device-controllable audio deck, such as a DAT or multitrack deck

  • Appropriate analog cables for your system

  • An audio interface

    Note: Some third-party PCI Express interface cards have a breakout box connected to the card with a special cable.

  • A USB-to-serial adapter or internal modem serial port adapter

  • A blackburst generator, with the appropriate cables to connect it to both your third-party audio interface and your audio deck. (For more information, see Synchronizing Equipment with a Blackburst Generator.)

  • An RS-422 video deck control cable

Synchronizing Equipment with a Blackburst Generator

With most professional editing systems, you capture video, audio, and timecode via separate cables. It’s important that when you capture, the VTR and the video and audio interfaces are synchronized via a common video timing signal. If digital audio samples and video lines and frames are not precisely synchronized, they eventually drift apart because they are captured at slightly different rates.

Using a common sync source is especially important when you are independently capturing long segments of video and audio to synchronize together later. If your audio deck and capture interface are not both receiving the same timing information, the sync between the audio and video portions of clips might drift over time.

A blackburst generator provides a common timing signal (or clock) to lock together the timing clocks of all devices in a system. This is sometimes referred to as external sync or house sync because every device in an entire facility can be timed to this common reference.

Professional VTRs, camcorders, audio devices, and interfaces often have the ability to accept sync signals from an external device. These connectors are labeled “genlock” (short for generator lock), “external sync,” “reference input,” or “reference video.” On some equipment, the normal composite video input of a device can be used to lock to external sync.

Important: To synchronize your video or audio devices and interfaces, they must all accept an external clock source (such as a blackburst generator).

When you genlock a deck and a video or audio capture interface, one output of the blackburst generator should be connected to the external sync input of the video or audio deck, and another output should be connected to the external sync input of your audio interface.

Figure. Illustration showing a typical setup including a blackburst generator.
To connect your audio deck outputs to a third-party audio interface for synchronized, genlocked audio capture
  1. Install a supported audio interface card in your computer, or connect a supported audio interface.

    For more information, see the documentation that came with the audio interface and your computer.

  2. If you are using a PCI Express card audio interface that came with a breakout box, connect the breakout box to the PCI Express card using the included cable.

  3. Connect the audio outputs of your audio device to the audio inputs of your audio interface.

  4. Connect the remote device control cable.

  5. To genlock your audio deck to your audio or video interface:

    1. Connect one of the blackburst generator’s outputs (there should be several) to the genlock or external sync input on your audio deck.

    2. Connect another of the blackburst generator’s outputs to the genlock or external sync connector on your video or audio capture interface (depending on which one you are using to capture audio).

    For more information, see Synchronizing Equipment with a Blackburst Generator.

  6. Plug in and turn on your blackburst generator.

  7. If you are using a blackburst generator, choose Final Cut Pro > User Preferences, and in the General tab of the User Preferences window, make sure that “Sync audio capture to video source if present” is selected.

  8. If you’re using Final Cut Pro to control your audio deck, make sure that the device control switch on the equipment is set to Remote.

  9. Once your deck and video capture interface are genlocked together, you still need to calibrate the timecode capture offset (found in the Device Control Presets tab in the Audio/Video Settings window) prior to capture.

    For more information about calibrating timecode for capture, see the Final Cut Pro User Manual.

Synchronizing Soundtrack Pro to External Timecode

There may be times when you will wish to synchronize Soundtrack Pro to an external video deck or audio recorder. Soundtrack Pro can “chase” (synchronize to) timecode sent by an external video deck or other LTC sources.

Note: This is not the same thing as device control, which allows you to remotely control a video or audio device for capturing and output. See the Final Cut Pro User Manual for information on device control.

There are two types of signal involved in this process. LTC (Linear Time Code) is an audio signal sent by a video deck or audio recorder. This signal can’t be read directly by the computer; it must be converted to MIDI Time Code (MTC) first. MTC can send via USB to the computer, and via MIDI cables for distribution to other connected MIDI compatible devices.

You will need the following equipment to synchronize Soundtrack Pro to external timecode:

  • A video deck or audio recorder capable of sending LTC time code

  • A device capable of converting LTC to MTC, such as the MotU MIDI Timepiece AV or Emagic Unitor 8 MKII

  • An RCA-to-1/4-inch audio cable, or a 1/4-inch-to-1/4-inch audio cable

  • A USB connection to the MIDI device

  • Possibly, a BNC-to-RCA female adapter

Setting Up the LTC Source Device

The LTC generator should be set up as the master sync device. All timecode settings should be set to “internal.” If available, Jog should be turned off. See the documentation for your particular video deck or audio recorder for specific instructions.

Setting Up the MTC Generator

Set the MTC generator to receive LTC signals:

  • In the case of the MIDI Timepiece, use the Clockworks control panel.

  • In the case of the Unitor 8 MkII, use the Unitor Control application.

Setting Up Soundtrack Pro to Sync to External Timecode

You can set up Soundtrack Pro to sync to external timecode.

To sync Soundtrack Pro to external timecode
  1. Choose Soundtrack Pro > Preferences, then click the Synchronization button at the top of the Preferences window.

    Figure. Synchronization pane of the Preferences window.
  2. In the Input section, select the Sync to MIDI Time Code checkbox.

  3. In the Output section, choose the frame rate for your project from the Frame Rate pop-up menu.

  4. In the Time Code Offset section, enter your tape’s offset in the Bar 1 At field. This is typically 01:00:00;00.

  5. Close the Preferences window.

  6. Depending on your timecode source, choose either View > Time Ruler Units > Drop Frame or View > Time Ruler Units > Non-Drop Frame.

  7. Choose View > Time Ruler Units > Set Starting Timecode.

  8. In the dialog that appears, enter the SMPTE position where you would like the sequence to start.

    This often is the same as the tape offset. If your timecode source is drop frame, be sure to select the Drop Frame checkbox.

    Figure. Starting Timecode dialog.
  9. Click the MIDI Sync button in the transport controls.

    Figure. Transport controls showing MIDI Sync button.

Soundtrack Pro will now “chase” (synchronize to) timecode sent by the tape deck or other LTC sources.