MACKIE TT24 - Manual (Page 51)

Mackie TT24 Digital Live Console Owner’s Manual Addendum v1.7
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4.0 Appendix Ramblings:
Front of House and Monitor Mixer Utilizing a Snake
In larger venues, a separate front of house and monitor console are used. In an all-analog
world, the inputs from stage are sent to both the front of house and monitor console by using
a splitter snake. Each console then receives the signal and each engineer has an independent
mic pre for the same input signal. This is easy to use but the engineers must deal with
extremely long and heavy cable runs making set up/tear down and audio quality an issue.
In a digital world, a digital snake is often used to convert the signal to digital and send it to
each console over a light weight digital connection. This also improves audio quality since
there is no signal loss over the long distance.
Shared I/O from a Single Analog Snake
A splitter snake can be rendered unnecessary if the two digital consoles used at FOH and
Monitor can pass signal between them digitally. If this is the case, only one of the two consoles
needs to be connected to the analog snake and it can pass these signals (or any other for
that matter) on to the other remote console. Effectively, the console and digital connection
are acting as a splitter snake. The remote console can also use the digital connection to send
outputs back to the console connected to the snake, which can then route the analog outputs
back to the snake. Thus either console can receive inputs from and send outputs to the analog
snake.
Shared Mic Pres from a Single Digital Snake
The digital snake solution is not always perfect, especially in a scenario where FOH and
Monitor desks are connected to the same snake. Only a single mic pre is used and it is instead
positioned in the fl ow before the signal is sent to both consoles. Thus the engineers don’t
have independent control of the mic pre, as changing the gain from one console will affect the
other. This can create havoc. For instance, if the monitor engineer were to reduce the gain
of the lead vocalists mic pre because they are getting feedback with the monitors, this would
lower the level of the vocalist at FOH making it hard for the audience to hear them.
To remove the symptoms of this problem, adjusting the gain from one console should not
affect the other consoles gain structure, and vice versa. Engineers have come to expect this
“gain compensation” when working with digital desks sharing a digital snake. This often done
by designating one console a master and the other a slave.
Shared Outputs from a Single Digital Snake
On the opposite side of things, the two consoles must be able to both feed signals to the single
digital snake with a fi xed number of outputs. Each engineer must be able to send signals to
the snake for patching to amps/active speakers.