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I have a Q802 USB mixer from Behringer, I’ll outline its use briefly and they get into my question.

  • I want to input a mic into the XLR, and the headphone jack from an iPad and the headphone jack from a TV into the line ins.
  • I want to do a mix minus (minus the TV) from the mixer’s (mono?) FX send into the 3.5mm mic input on a Playstation 4 controller.

Now, I’m struggling to understand what might happen if I mess up and patch the wrong type of cable in somewhere. I’ve researched to the best of my ability, but things seem to start getting complicated when mixing and matching stereo and mono, balanced and unbalanced ins and outs.

The iPad and TV sources are stereo, so they can go in the dual TRS inputs, right? The inputs are balanced on the mixer, so I’m guessing I use balanced cables, but does it matter whether or not the iPad and TV are balanced?

The FX send going to the Playstation, this doesn’t seem to be a configuration you see every day and I certainly can’t find any information about it. The mixer’s manual does not specify balanced or unbalanced.

I’m really just looking for some advice about what to use as I’m a complete beginner in audio and don’t want to fry anything.

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Balanced vs. unbalanced audio actually has nothing to do with impedance.

Simply;

Unbalanced audio uses one wire for signal and one wire for ground. Hope for the best.

Balanced audio uses two wires for signal and one for a sheild, but not necessarily a ground. The two signal wires are the same signal, but one is "flipped" 180 degrees out of phase. This means any noise that occurs on the signal lines is mostly negated by the difference amplification at the receiving end. Think of it as the receiving amp flipping the two signal wires back in phase, thereby putting any accumulated noise out of phase with itself.

There's way more to it than just the noise-cancellation, and there are at least a couple of common types of balancing scenarios, like "fully-differential" balancing (what I described above) and "impedance balancing" which is a kind of weird compromise found in many small/affordable mixers and outboard gear.

The input and output impedances of audio devices are part of their design, not the cabling.

"The iPad and TV sources are stereo, so they can go in the dual TRS inputs, right? The inputs are balanced on the mixer, so I’m guessing I use balanced cables, but does it matter whether or not the iPad and TV are balanced?"

The iPad and TV are unbalanced sources, so use unbalanced cables to the mixer's dual TRS input jacks.

With the setup you have described in your question, I don't think there's a strong likelihood of frying anything.

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    Correct terminology for this property is "Common Mode Rejection" which is the ability of a balancing transformer, or differential op-amp to cancel identical signals which appear on both inputs of an op-amp. Note that "star-quad" design cables improve the common mode rejection for interfering signals that are induced close to the cable. Close induction can cause a difference in induction levels in the positive and negative signal lines which can reduce the ability of op-amps to perform common-mode rejection. – Mark Nov 23 '18 at 12:19
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In general, balanced means the impedance is matched, unbalanced means the load impedance is greater than source impedance, which is OK. Same can be applied to cables.

The use of unbalanced transmission lines is possible because the lenghts are comparatively too short for deterioration of signals, and the only time you need to worry about impedance matching is when connecting loudspeakers to a power amplifier, e.g. the physical end of the sound system.

That and the quality of electrical installations in your environment, which may introduce ground loops and such, but that is matter of taste, needs vs. means, etc.

The FX sends are designed to go basically anywhere, so a Playstation will be fine, I think.

  • Down-voted because answer is factually incorrect. Balanced Audio is unrelated to impedance matching. – Mark Nov 23 '18 at 12:13

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