I would love for you to explain tie lines in detail. My only understanding of tie lines are the analog connections under the booth that says tie lines on it.
Tie Lines simply allow you to route inputs and/or outputs to different locations over the Allen and Heath connections (Slink, GigaAce, etc) without using up any of the processing channels on the console. It’s very similar to how you might route I/O from a Dante or Waves card, but through the proprietary A&H connections instead. It can be routing of analog I/O connected to the console, but you can also route digital I/O that’s coming/going from another source as well.
For example, if you have a digital snake and two consoles, the digital snake can only be physically connected to one of those consoles. If you need to send the channels to the second console, you would use tie lines to do this.
Or if you have an analog input/output connected to one console due to the physical location of the device and console, but need to use that input on/from another console, you would use a tie line to send that input/output to/from the second console. All without using a channel on the board that the input is physically attached to.
Or if I had two consoles, but only one had a Waves card in it, I could use tie lines to route Waves I/O to the second console through the Allen & Heath connections rather than having to buy a second Waves card.
The downside to using tie line is that the console must be turned on to pass this audio. If you had two consoles and had tie lines running through console 1, it has to be turned on to pass audio to console 2 even if you don’t need console 1 for that particular event.
Hopefully these use cases help explain why/how you would use tie lines.
