Mixing Consoles - Signal Flow
Signal flow is the work of routing the audio signal from it’s source to destination, whether this be from a mic to an amp (macro), guitar to a mixer (macro), or daw output to headphones (micro). Any aspect of audio production where sound travels requires the signal to flow to it’s required destination comes under the topic, and this is differentiated by referring to either macro or micro signal flows depending on its scale, and they are typically charted with a signal flow diagram.
In class we looked at a 24-track mixing desk, desks being the central routing system to any live sound or studio setup, the one we viewed had quarter inch Jacks and XLR inputs on the back, 3 Jacks and 1 XLR per channel strip, making up all together the I/O section of the console, along with insert inputs and second track option giving the deck effectively 48 inputs in total depending on the routing utilised. Input levels themselves can vary depending on the source, consisting of mic level, instrument level and line level (+4Dbs) from lowest in level to highest.
These inputs then feed through the channel strips, where audio effects such as EQ or panning could be applied, as well as the meter bridge to read the levels of each track. Routing options on the deck allowed for the signal to be sent to specified bus channels, where the mix could be split from the main mix and be routed elsewhere for purposes such as monitoring, this can be achieved with busses where audio can be sent and combined with other signals passing through separate channels to create mixes different from the main. These are set with the aux sends where the signals are copied, and are leveled by the fader dependant on whether it is set to pre or post-fade, pre being the bypass.
In the class we also had the opportunity to setup a practical example of a signal flow, this consisted of setting the dynamic mic up on the stand, connecting the male end of an XLR in, securing to the mic stand allowing cable slack, then inserting into the channel strip line input, ensuring adequate input gain for the microphone, setting the strip to route to the main mix and increasing the levels first from the channel strip and then on the main mix out to send the signal finally to the speaker system.
