I was going to make some guitar cables and there is one thing on which I am not so sure about. If I have a double shielded cable (ordinary audio cable consisting of signal, shield 1, shield 2), where should I connect the shield 2 in the jack? Ground on both ends? Leave it floating or leave it floating on one end? Thanks kindly for all answers.

  • A far more common cable is that used for mics, with two inner cables, surrounded by a sheath. The sheath either being around the two, or each separate. Maybe that's a better bet? No answer, thus comment.
    – Tim
    Jan 7, 2017 at 9:36

1 Answer 1


If you connect the outer shield to the inner shield, then you've defeated the purpose of using double shielded cable. If you don't care about double shielding and are just trying to wire up a cable, then you can just do that.

If you have some input where the sleeve contact is grounded and the ring contact is treated as a reverse polarity signal, then it makes sense to not connect the outer sleeve to the inner one, but you'd have to use TRS connectors to make it work and it would be better if the inner shield were just another wire instead of another shield.

I guess I can't figure out the purpose of double shielded cable when it comes to musical instruments.

  • Is there any application where you'd connect the two shields differently? I think in most “double shielded” cables, the two shields aren't really seperate anyway but just e.g. a foil shield with additional braided wire wrapped right around it. It's basically still just a single shield with composite structure. But I might be missing something. Jan 7, 2017 at 12:29
  • @leftaroundabout No, that's pretty much it. Braided shields have good flexibility and work well at low (audio) frequencies. The trade-off is 90% coverage. In theory, adding a second braid would increase the coverage to 99% by covering 90% of the remaining 10%. Other types of shields cover more area but don't stand up as well to repeated movement.
    – Blrfl
    Jan 7, 2017 at 12:52
  • You pretty much only use something like this in a balanced form but even then, it's probably not the best type of cable. I think Todd's right.
    – Doktor Mayhem
    Feb 6, 2017 at 10:44

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