Today’s question was too long and confusing to print in its original form so we’ve paraphrased the core idea for you.
“I have a number of balanced and unbalanced inputs for my mixing boards on wall plates around the studio. Each terminates to a balanced or unbalanced patch bay depending on what type it is. From there they can be patched to my mixing boards. My mixers have 8 or 12 balanced inputs and the rest are unbalanced. Each is fed with a balanced patch bay. Sometimes I need to connect more than 8 or 12 balanced items or I may need to connect unbalanced sources. Can I just patch from the unbalanced bays to the balanced ones driving the mixers? What’s the best way to do this?”
I know, it’s still confusing. Let’s back up a bit here. First, it is usually not a great idea to run unbalanced signals more than 20 to 30 feet total. In most recording rooms sources that aren’t already balanced are usually driven into a direct box, and from there that balanced signal is passed on to the mixer.
It is possible to connect unbalanced and balanced gear together. The rules for going from unbalanced to balanced, and from balanced to unbalanced are different, but similar. It gets confusing because there are a number of ways to do it, with the best one dependant on how the system is set up and the properties of the individual items in question. You mainly need to make sure you get the positive (hot) signal to pass through. Then you have to decide what to do with the extra pin of the balanced signal. Your choice is usually limited to leaving it ‘floating‘ (often best for balanced into unbalanced connections) or shorting it to ground (often best for unbalanced to balanced connections). There are other variations of these techniques that can produce excellent results. For example (and we’ve covered this in a past Tech Tip) you can use a resistor to make an unbalanced line look balanced to a balanced input, which gives you much better noise suppression.
Of course you don’t want to do any of this with microphones. They need to always be balanced from beginning to end with no tricks (unless you have a rare unbalanced microphone). If you don’t have enough balanced mic inputs on your mixer you will need to look into outboard mic preamps. These can output a line level signal that can be unbalanced if necessary. Keep in mind unbalanced signals should not go more than 20 feet or so.