XTA DS8000/D - Manual (Page 26)

DS8000 Operator’s Manual Page 26
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Appendix I: Appendix I: Appendix I: Appendix I:
All about splitters
A splitter, or distribution system, is responsible for providing multiple feeds from a single
audio source to enable different processing devices to share the same input signal. In this
way a signal is split and distributed to multiple destinations.
The ideal device will perform this task with minimal signal degradation and minimal
interaction between the destination(s) and the source itself.
Signal degradation may be caused by several factors:
1) Noise and interference pick-up due to low-level signals being transmitted long
distances, perhaps using unbalanced cables.
2) Hum and electrical interference due to multiple ground (earth) systems — at each
signal destination.
3) High frequency attenuation due to cable capacitance causing HF roll-off, especially
when dealing with long distance cable runs
4) Overall signal level may be attenuated due to the sharing (splitting) of the signal
across multiple destinations, leading to a poor signal to noise ratio.
The task of signal distribution can, at it most basic level, be as simple as a “Y-Split” cable
which feeds two inputs from a single output, perhaps to drive two amplifiers from the same
mixing console output. Indeed, this is what happens when the “Link” output is used on many
amplifiers — the link socket is just wired in parallel with the input, so splitting the signal in
two.
However, consider a slightly more complex scenario, and one which is quite commonplace in
the field of live concert audio.
The microphone signals derived on-stage are required to travel
considerable distances to provide audio for several different
requirements. The signal from the microphone is at a very low level and
so prone to picking up noise from other equipment on stage such as
lighting dimmer packs, computers and RF sources such as mobile
phones and wireless packs.
This signal must be split and fed to both the Front of House and Monitors mixing consoles
…as well as providing a feed to an off-site “OB” (outside
broadcast) truck, possibly several in the case of large
sporting or news events.
Low Level
Mic Signal (~-40dBu)
Front of House
Mixing Console
Monitors
Mixing Console
Outside
Broadcast
Truck