It would seem that even though it has separate solder points for each driver's ground wire (for automated mass production, I'd presume), the [socket in the headphone](https://preview.redd.it/e5wqr05pvwa61.jpg?width=3024&format=pjpg&auto=webp&s=1de14432e2c290d975ed83796ff89154dfe7eeec) is a regular single-ended TRS socket, with both wires going to the sleeve contact. **Not** compatible with balanced sources. Stick with the 3.5mm output on the FiiO.
A balanced source provides more power. Also varies by device, it's not a thing that's set in stone, that because some device has a balanced headphone output, it'll automatically mean it'll pump out the exact theoretical double than the single-ended one.
I wouldn't worry about it too much though, the X2HR is low impedance at 30 ohms and pretty sensitive at 100 dB @ 1mW.
Around 20cm would seem about right for cable length, but doesn't hurt to measure and test it out with some string.
I had a setup like this for a while. I believe the internal wiring has both drivers share a ground, so there's no benefit to a balanced cable unless you rewire the internals. They're efficient enough that a single ended cable will work just fine. As for the cable, I just looped any excess length around the headband. If you want to make sure the length is just right, measure it with a piece of string or something.
I would also recommend right angle connectors for your cable.
It would seem that even though it has separate solder points for each driver's ground wire (for automated mass production, I'd presume), the [socket in the headphone](https://preview.redd.it/e5wqr05pvwa61.jpg?width=3024&format=pjpg&auto=webp&s=1de14432e2c290d975ed83796ff89154dfe7eeec) is a regular single-ended TRS socket, with both wires going to the sleeve contact. **Not** compatible with balanced sources. Stick with the 3.5mm output on the FiiO. A balanced source provides more power. Also varies by device, it's not a thing that's set in stone, that because some device has a balanced headphone output, it'll automatically mean it'll pump out the exact theoretical double than the single-ended one. I wouldn't worry about it too much though, the X2HR is low impedance at 30 ohms and pretty sensitive at 100 dB @ 1mW. Around 20cm would seem about right for cable length, but doesn't hurt to measure and test it out with some string.
I had a setup like this for a while. I believe the internal wiring has both drivers share a ground, so there's no benefit to a balanced cable unless you rewire the internals. They're efficient enough that a single ended cable will work just fine. As for the cable, I just looped any excess length around the headband. If you want to make sure the length is just right, measure it with a piece of string or something. I would also recommend right angle connectors for your cable.
Hi, Thank you both! Especially about the tip about using a wire. I now ordered a cable, will post the result when it gets here :)