The funny thing about the words “unbalanced” and “balanced” cables is that you don’t really have to know what they mean in order to use them. Uses of these cables are typically common knowledge or the information about what cables you need for your gear is given to you when you buy the gear. The result of this is that the meanings of these words get thrown to the backburner of our learning priorities.
But what does, “unbalanced” and “balanced” actually mean? Today I want to give you a better understanding so that you can really visualize the difference; perhaps the only reason is to indulge your craving for knowledge, but maybe it will actually help you somewhere down the road when you’re in a session trying to troubleshoot something.
Going forward, I’m going to use TS and TRS ¼’’ cables as an example. Keep in mind that the information I give you here is true for all unbalanced and balanced cables.
If you’re in audio school, you’ll often see this overview comparing TS and TRS cables:
Thanks E-Home Recording Studio for the pic. For educational purposes only.
TS: tip, sleeve; two conductors; unbalanced; long runs will pick up noise
TRS: tip, ring, sleeve; three conductors; balanced; can have a long run with no noise
In the cases above, noise refers to electrostatic noise from electrical spikes and static in the audio system that gets through the conductors and gets into your audio system… womp. Nobody wants that, but it happens all the time.
First let’s talk about the TS cable, the unbalanced cable. If you were to take the cable apart, you would see a wire surrounded by a ground wire. The goal of this ground is to protect the main signal (that is traveling along the other wire) from noise.This doesn’t always work though, and so sometimes noise gets in anyway. As the cable travels over distance, noise from other electric elements in the room starts to get added to the signal wire. The longer the cable is, the more chance there is for noise to get there. This is the reason you should try to keep your unbalanced cables shorter than 20’.
Thanks aviom.com for this graphic. For educational purposes only
Here is where things get interesting. Let’s talk about balanced cables now. We’ve all heard that balanced cables can have as long of a run as you want without adding noise. How is the signal wire protected from the noise? Well that’s a very easy question… It’s not.
Balanced cables have three conductor wires. There is one that acts as the ground, which we know tries to help protect the signal from noise getting in. Then, there are two other wires where the signal travels. A copy of the same signal travels along those two wires.
Here comes the kicker. Their polarities are the opposite of each other. We know that when signals’ polarities are reversed, they’re inaudible because they cancel each other out. Now, when the cable is travelling over space, the noise that gets in is added to those wires equally, with the same polarity. So now you have two wires carrying signals with the polarity flipped on one and noise where the polarity is the same on both. When the wires finally reach their connectors and reach their piece of gear, a circuit inside the gear flips the polarity of one of the wires, making the signal in phase (or with the same polarity) and the noise 180 degrees out of phase (or with reversed polarity).
Thanks aviom.com for this graphic. For educational purposes only.
I hope you found this info helpful. If you have any other questions about this topic or if you have any other questions, don’t hesitate to reach out.