Apple Soundtrack Pro 3 - Manual (Page 521)

Amplifiers and Signal Levels for Unpowered Speakers
Unpowered speakers require signals with higher voltage than consumer and professional
equipment can provide directly. These levels are known as speaker level audio signals,
while audio devices such as tape recorders and audio mixers usually provide line level
signals. An audio amplifier boosts line level signals to speaker levels to properly drive
speakers. Wide-gauge speaker cables that can handle the higher electrical strength of
speaker levels are used to connect the amplifier to speakers.
Connecting Professional Video Devices
Regardless of what format or video interface you use, the same basic steps apply when
you connect a VTR or camcorder to your computer.
Connecting Professional SD Video Devices
If you’re using a format other than DV, such as Betacam SP or Digital Betacam, you need
to install a third-party video interface that supports the proper signal for the format you’re
using. Some video interfaces can digitize analog video input and output (for analog
formats like Betacam SP), while others capture video only if it is already digital. In either
case, the video interface encodes the video information using a codec, which may or may
not apply compression to the video data to make it smaller while stored on disk.
Compression settings used by video interfaces are typically controlled by software and
use a variation of the M-JPEG codec (although the name of the codec itself may not reflect
this).
Unlike DV video devices (which use a single FireWire cable), third-party interfaces send
and receive video, audio, and device control data on separate cables. For remote device
control connections on professional equipment, 9-pin (DB9) connectors are used.
A Recommended System Using a Third-Party Video Interface
To set up a system using a third-party video interface, you need the following equipment:
• Your computer and display
• A non-DV format video device (a camcorder or deck)
• Audio and video cables for your system
• A third-party capture interface installed in or connected to your computer
Note: Some third-party video interfaces have a breakout box connected to the card
with a special cable, which is included.
• A USB-to-serial adapter or internal modem serial port adapter
• An RS-422 video deck control cable
• A blackburst generator, with the appropriate cables to connect it to both your
third-party video interface and your video and audio devices
521 Appendix C Working with Professional Video and Audio Equipment