Headphone cables & my findings

So after being annoyed by not understanding why 8x24AWG or 4x18AWG + 4x22AWG single ended cables existed I had to do some research.

Firstly, if you disagree with the below, feel free to contribute, however please do not start a flame fest.

Ok so to start I did the current requirement calculation, assuming no impedance in the line, however if you insist the headphone cable is going to be around 1.8m (6 feet), therefore about 15ohm resistivity could be added, but basically...

Take a Woo audio WA2 @ 1100mW output (max) @ 300 ohm (HD800)

Voutput 18.115V, current = 65mA

A 24awg copper wire has a current carrying capacity (ampacity if you insist) of 0.5A

It has a 0.511mm diameter (0.255mm radius)

So I was left asking, why the heck do people have 8x24 AWG cables going out there... considering you wont be utilising a single cable not to mention 2 per channel.

I assumed it had to do with Gauss's Law/Skin Effect... So I calculated:

According to skin affect calculations:

* Assuming copper resistivity and permeability does not change whether its OFC or OOC...

at 1Hz the skin affect of copper is 65.19644702mm
at 50KHz the skin affect of copper is 0.291567375mm

Concluding that a single 24awg copper wire which is 0.511mm in diameter (0.255mm is radius) which current carrying capacity is roughly 0.5A, would be fully utilised from 1Hz-50kHz.

The only time it would start being an issue is around 65kHz where the skin affect becomes less than the radius of the cable, to which one could continue to calculate when the skin effect depth would be too small to carry 65mA in scenario.

It would seem that a single 24Awg copper cable is sufficient to run a pair of HD800s (300 ohm) headphones @ 1100mW output.

meaning 1x24AWG for L+, 1x24AWG for R+ and 2x smaller AWGs for gnd.

The only other arguement would be whether silver coated conductor would help the current at different frequencies move in anyway different that copper.

I did not say they do not exist, I said I do not understand why they exist, whats the science/theory behind 8x24awg cables?

I am more than happy for people to say that, but if the WA2/WA22 are supposedly amazing for the HD800, then theres no real arguement there tbh.

I believe the HD800s are rated around 500mw per driver or something like that? cant remember, anyways it doesn't matter.. my explanation pretty much shows that you cant really go wrong with 4x24awg cables...

Now comes the next question, why the heck do XLR female plugs use bronze contacts, and male plugs use silver/gold.

Ideally they should be made of the same material...

Quote:

Originally Posted by Steve Eddy 

As far as PLATING goes, female plugs may be gold or silver. When you say bronze, you're talking about the underlying material the contacts are made of.

 

The reason the females use bronze, is because they're female. They fit over the male contacts and have to maintain spring pressure on them. Regular brass or copper don't make good springs. So female contacts are typically made with phosphor bronze (CuSn8) which does make good springs.

 

se

 

 

 

Thank you very much for that, makes alot more sense now, noticed some XLR female plugs dont have any coating, just CuSn8... thats what I was confused about. 

http://www.neutrik.com/en/xlr/a-series/nc4fah-0

for example.