crystal User Manual
Version: 6.6.0/2
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10. Audio Mix Engine
10.2
Summing Buses
10.2.1
Bus Anatomy
Each summing bus can be mono, stereo or 5.1.
The naming, assignment of signal processing and bus attributes are all made by the system configuration.
The first pair of buses is always pre-defined as stereo PFL 1. The remaining buses must be defined using one of
the following bus types:
·
Sum Bus
– these are normal summing buses which can be allocated DSP and assigned to a fader strip.
Typically, they are used to create main outputs such as PGM, RECORD and AUX.
·
GP Sums
– these are general purpose buses which cannot be allocated DSP or fader strip control.
They are ideal for applications such as a talkback or AFL.
·
Conf Buses
– these are special buses which have facilities for generating a conference system (for mix
minus / N-1).
·
PFL
– if required, additional PFL buses can be defined (up to 5). For example, to create independent
listen buses for a multi-operator console.
The maximim number of buses, and their DSP resources, is determined by the type of System Core. The DSP
options include EQ, Dynamics and Limiter functions which operate in the same manner as for a Source. Delays
are specified separately. Loudness Metering, conforming to EBU R128, is also included. All buses are output at
unity gain (0dB), unless they are adjusted by a fader strip on the surface.
A stereo bus uses two and a 5.1 bus uses 6 summing bus resources.
The rest of this section describes the
Sum Bus
elements. For information on the other bus types, please see
.
10.2.2
Creating Sum Buses
The "
Sum Bus
" branch of the ‘Tree Definition’ is used to insert and configure summing buses.
Each bus can support several sets of parameters. Switch between them using the menu tabs at the top of the
parameter area.
The most important fields are the
Name
and
Type
(defined in the
Parm
tab):
A sum bus
must
be named before it can be referenced to other elements via the 'Tree Selection'.
For
crystal
,
sapphire compact
and
sapphire MK2
, the type is defined when you insert the summing bus
element.
