For some reason low voltage, high quality audio interconnects seem to be made of 3 wires braided together, when normal low voltage audio wires are two wires surrounded by a grounding sleeve.
I'm a college student, and I think I understand exactly how both of these methods can cut down on "internal" interference, but if I'm correct then the braided wire method wont do poop when it comes to helping block external magnetic field, which is why the grounding sleeve is great because it acts as a Faraday cage around the signal bearing wire.
Is there something that I don't understand about braided wire that is somehow magically better than protected wire for carrying an analogue voltage?
So I guess my question is: why does a cable that looks like this…
Cost more than a cable that looks like this…
Best Answer
If you have a balanced audio signal (e.g. XLR), then the idea behind a twisted pair is any interference that one wire picks up will also be captured by the other wire. The device that receives the signal only cares about the difference between the two levels, so any common mode noise can be ignored. This is extremely important for long runs (lots of opportunity for noise to intrude), or microphones (very low signals). Good cables will also be shielded, as the wires aren't "perfectly twisted" with zero area between them, so are still slightly susceptible to interference.
However, with unbalanced audio (e.g. phono plugs, jack plugs, TRS (like your picture), etc...), you only have one conductor, so must totally shield it to prevent noise. Still, such runs are both short and amplified, so the effect of interference will be smaller and is generally inaudible.
A "braided cable" like the one you picture is probably electrically worse than a typical foil-shielded audio cable. Such a braid would also be counterproductive in balanced audio as the conductors are unnecessarily separated.
As for why they are braided that way, it's because it looks kewl (so they can charge more), and in that 6" cable, nobody will ever hear the difference.