Manual

147 PRO X User Manual
Chapter 28: Delay Compensation
(Latency)
A time delay is induced in a channel’s signal by placing, for example, an insert
or GEQ in its path. This delay aects system latency and can also produce
undesirable audio eects. To overcome this the PRO Series incorporates a system
of user-congurable delay compensation parameters. These are presented to the
user in the form of button-selectable options on the GUI and can be switched on
or o to suit the current application.
Insert compensation
If a channel insert is active, it takes a nite amount of time for the signal to
be sent through an internal or external eect and returned to the channel.
Therefore, with no insert compensation, channels with inserts assigned are
delayed more than channels that don’t have an insert assigned to them. If two
correlated signals with dierent delays are mixed together, this can produce
comb ltering.
External FX
Analogue input XLR to
Input channel with
Delay
= 0ms
external insert
PEQ/
DYN
Input channel with no insert
and no compensation
Input channel without insert
and with compensation
input channel output = 2.2ms
Delay through
D/A and A/D = 1.11ms
DYN/
PEQ
Analogue input XLR to
Delay
= 0ms
PEQ/
DYN
input channel output = 1.08ms
DYN/
PEQ
Analogue input XLR to
Delay
= 1.09ms
PEQ/
DYN
input channel output = 2.2ms
DYN/
PEQ
Analogue input XLR to
Input channel with
Delay
= 0.33ms
internal insert and
PEQ/
DYN
input channel output = 2.2ms
Delay through
internal FX = 0.7ms
DYN/
PEQ
Internal FX
with compensation
To avoid the comb ltering eect, the PRO Series insert compensation works
by delaying all channels except the ones that have inserts assigned. In practice,
the actual delay used for compensation depends on the type of insert (internal/
external) and its location (stage/FOH). Each channel type or layer within the
control centre, such as, input, aux, master or matrix, has its own parameter
controlling the delay compensation for that layer. This provides the user with the
maximum exibility and allows the control centre to be congured for the lowest
latency for a given application.
GEQ compensation
Output bus channels have the ability to have a GEQ inserted into them, which
incurs an additional delay in their signal path. With GEQ compensation active, a
delay is inserted into the output buses, which is removed when a GEQ becomes
active. This ensures that all bus outputs of the same type are aligned, regardless
of whether they use a GEQ or not.
GUI Delay Compensation options
PRO Series delay compensation (latency) is congured in the
Delay Compensation section of GUI menu’s Preferences Delay screen.
For a description of the delay compensation options and details of when best to
use them, see Table 17 (below). In this table the Description column explains
what happens when the delay compensation option is selected (switched on)
and the Latency (ms) column shows the value that the overall system latency is
increased by.
>> To access the delay compensation options
At the GUI, choose home  Preferences  General and then click the
Delay Compensation tab