Star quad cable: Why does the white wire have noticeably less resistance?

Question

I ordered the star quad Canare microphone cable, but I do have a question: why is the resistance of the white wire noticeably less than the resistance of the blue and shield? (The blue and shield are roughly the same resistance.)

I have made 25 ft. XLR cables and pin 2 (white wire) is noticeable less than the other two. The other two are roughly .50 Ohm and the white wire pair is .35 Ohm. This holds true for each cable I made.

Very curious. Would like to quickly pick an expert's brain. Thanks

http://www.canare.com/ProductItemDisplay.aspx?productItemID=53

As far as I can see the strands are all same gauge. I would have thought the shield would have the least resistance.

Answer 1

I suspect it's an issue with your measurement technique. The specifications from the product link provided list the resistance, and there are only two values, one for the shield, and one for the conductors. That each conductor isn't listed separately implies they are all the same.

Further, that this is sold as a microphone further implies that the resistance is the same for each conductor. Were it not, it would not work as a balanced cable.

Measuring small resistances (certainly <1Ω) is difficult with an ordinary ohmmeter. In this range, the resistance of the test leads and the contact resistance can be significant. The precision of some meters may not be sufficient in this range. It can take some care to get an accurate measurement.