So I posted a thread on re-cabling a headphone (I was ultimately successful) but I was left feeling like an amateur (which I totally am) after a post in that thread that as super technical and detailed.
1. What is 3 conductor/4 conductor cable ? How do I know when to use what? (Are there 1-2, 5 + conductor cables?)
2. Can someone help me understand how to pic an "appropriate" cable for when one does a re-cabling job regarding headphones/earphones?
Thank you,
As Amirm already stated in his short and to the point reply: For balanced wiring you need 4-wire, when your headphone only has a 3.5mm or 6.3mm TRS jack 3-wire and 4-wire can be used.
You can connect a 4-wire headphone to a balanced and 'common' TRS jack headphone amp.
You can NOT connect a 3-wire headphone to a balanced amplifier, regardless if there are 'conversion cables' that make you think it is possible.
recabling as in replacing a 'fixed' wire or as in replacing a cable that connects to the headphone via connectors ?
Reasons to change a cable.
1: the cable is broken, intermittend
2: You need a longer or shorter cable
3: your cable is very microphonic
4: the cable still works but the outer sheathing is damaged and you expect it to fail soon.
5: You don't like the feel/springyness/stiffness of a cable
6: you want an inline mic or don't want/need one.
When the headphone has a 3.5 or 6.3 mm TRS jack with 1 ring, 1 tip and a large contact you can use 3 and 4 wire cable
When the headphone has a 2.5mm TRRS (2 rings in the jack) or a 4-pin XLR or a 3 ring 4.4mm Pentacon Jack you need 4 wires.
Don't confuse a headphone cable with a 3.5mm TRRS (Tio Ring Ring Sleeve) connector that also has a microphone/remote function in it with a 'balanced' 2.5mm TRRS jack. These 3.5mm TRRS jacks also have a second 'ring' but that ring is for the microphone/remote function. Not as balanced input option.
Basically with 3-wire cables the only wire in it that really matters is the resistance of the 'common return' wire. That needs to be as low resistance as possible.
using 4 wire cables and ensuring the 'common' (sleeve) wire is only connected in the TRS jack plug is technically (not necessarilly audible) the better solution.
Technically a 4-wire cable is always 'better' (certainly with low impedance headphones) than a 3-wire cable.
Even when the headphone uses a 3.5mm or 6.3mm TRS Jack plug and has/had a 3-wire cable and you are replacing that wire and have to open up the headphone to do so and need to solder wires anyway it is technically better to use 4-wire replacement cable and connect 2 (-) wires in the 3.5 or 6.3mm TRS jack and rewire the cabling in the headphone so that the '-' wires in the headphone itself are not connected anymore.
When the headphone itself only has a 3-pin mini XLR (AKG, Beyerdynamic) or single entry cable with a 3.5mm or 2.5mm TRS jack (only 1 ring) then it is rather 'pointless' to use 4 wire cable. Technically though you can parallel 2 'return wires' and by doing so cut the resistance of the return wire in half.
How audible this will be thus ONLY depends on the resistance of the return wire + headphone impedance.
Measurable it will be different.
Don't expect a cable to provide a higher sound quality, improve bass or tame treble. When you experience this as an effect you can be certain your brain is telling you porkies and your wallet has been made lighter for the benefit of the seller and manufacturer of said illusion.
Or... the different sound (in case of a 3-wire TRS jack cable) could be caused by a relatively high 'common return wire' resistance. This should affect stereo imaging the most though.