I don’t get the difference….
In: 4
When it comes to audio, balanced is a more complicated way of doing things, but it gets rid of noise and interference, while allowing for more power. How it works depends on which piece of gear you’re talking about. There’s basically one definition that applies to electronics like the DAC (digital-to-analog converter) and the amplifier; and a slightly different definition when it comes to the headphones themselves.
Let’s start with the electronics. A simple unbalanced connection from the DAC to the amplifier uses RCA cables, which have 1 signal wire (max 2 volts) and 1 ground wire each. XLR balanced cables have 3 wires per cable; 2 for signal (so max 4 volts) that cancel each other out at the amplifier (so no ground), and a shield wire to absorb interference. If there’s some interference on one of those signal wires for the XLR, it “cancels out” with the other at the amplifier for a cleaner signal. 4 volts instead of 2 also allows you to use a longer cable without the signal dropping off.
So now that you have a balanced signal coming into the amplifier, let’s talk about the headphones… Simple unbalanced headphones have a signal wire going to each ear cup, and a Y-shaped shared ground wire. (3.5mm and 6.35mm connectors are 3-pole.) This shared ground can cause a tiny bit of the signal to “bleed over” from one side to the other, called crosstalk. If you try to send a signal to just the right channel, 99% will come out the right side while 1% comes out the left and your brain interprets that as a slightly narrower soundstage.
Balanced headphones have 2 signal wires going to each ear cup. Here, the signals are slightly different. They’re close, so they basically cancel each other out at the driver (and don’t need a ground), but the difference between them is what causes the driver to move and generate sound. There is no crosstalk because there is no shared ground wire. (XLR headphone connectors are 4-pole. 4.4mm “penta-conn” connectors are 5-pole and have a shield wire like the XLR electronics connectors. It’s confusing.)
When hi-fi equipment says it has a “truly balanced circuit” it means balanced inputs and outputs so there’s no ground wire anywhere in the chain.
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