Just What Is A Mix Minus, Anyway?
And Why We Found A Better Way
The simplest way to describe a mix-minus is a “clean feed.” We take a mix bus such as program, subtract a source from the mix and send that feed to a remote location. For example, when you feed audio to a telephone hybrid, you want the caller to hear everything on the air except for their voice; if their voice was part of the mix it would come back to the caller a split second later and make it hard for the caller to speak. For remotes, sending a program feed to a codec, minus the inbound audio from the codec, not only eliminates a delayed repetition of the remote audio at the remote site, it helps to eliminate feedback at the remote site if they are doing local sound reinforcement along with their remote.
In the days of analog consoles, you would create a mix-minus by using an aux bus and punching everything into the aux except for what you want mixed out. This method gets the job done, but it requires the operator to keep track of which bus feeds what source and there’s room for error.
Logitek came up with a better way. When you set up your console, you assign sources that need a mix minus to their own mix minus bus. The console then keeps track of what needs to be mixed out and automatically generates the right mix. (We also give your operator a way to easily talk back to the remote off-air with a simple button push.)
On average, we find that most studios average from 6 to 10 mix-minus buses today. With 24 mix-minuses standard on our equipment, we give you room to grow as remote technologies evolve.