A-2
Dolby Laboratories Information
Dolby Surround: Getting Started
Console Buss Assignment
Interfacing with standard studio equipment, the professional SEU4 Encoder and SDU4
Decoder enable mixing in Dolby Surround for consumer release formats such as video,
broadcast and CD.
The SEU4 has four inputs for Left, Center, Right and Surround channels. It is not always
necessary to use the Center input. This signal is also created by central panning across
left and right groups.
On consoles specifically designed for surround mixing, use the Left, Center, Right and
Surround output busses. On stereo buss consoles, assigning two stereo output groups
designated “Left and Right,“ “Center and Surround,“ will provide the most flexible
operation. In a feature or drama production, while many sounds will remain static, it
enables the active panning of sounds, such as front to back fly-over effects.
Where a simpler mix is desirable, a Left and Right group will suffice, with a spare channel
or auxiliary send employed as the Surround send. This is particularly useful in sports or
live events where only a general ambience is usually required.
Mixing in Dolby Surround
Although no fixed rules apply, some basic mixing techniques have evolved that are
universally practiced. In features or drama production, dialogue and on-screen effects are
generally centrally positioned to provide an important visual and aural focal point.
Music and atmospheres are spread around all channels to create an enveloping ambience,
with spot effects panned to follow movement.
Similarly, in sports or live events, the main action and commentary are usually centerd,
with the audience diffused to create the atmosphere of being there.
In music-only production, a regular stereo approach provides the basis for creative
surround imaging without the constraints of matching sound to picture.
Being a system reliant on phase and signal relationships to determine imaging, it is
important to always monitor the final decoded output. For example, a typical stereo
effect like a reverb will provide a degree of center and surround information along with
the normal left and right channels. In practice, especially where time and resources are
limited, such “signal leakage” often assists in producing a quick, yet effective mix.
Audio Sources
Program material should be derived from standard multi-channel sources to enable
maximum control over sound positioning. The more independent these sources are,the
more creative the production can be.
MAIN
