2. cables
  3. 162924-94940

Building Balanced XLR Cables

I am building XLR cables using 3 conductor + shield wire. Typically I would solder the shield to ground, 1 wire to hot, and 1 wire to cold. Should I connect the 3rd wire to the ground (shield), use the 3rd wire as the ground (not use the shield at all), or not use the 3rd wire at all? Thanks in advance.  
drumfishie
auxinput
2,920 posts
 
ah, just re-read your first post.  If you have a braided wire shield, I would solder that to the "shield" connection on the source XLR plug (typically a female plug).  If you have a "floating" braided shield, it tends to create capacitance and reduces high frequency response in the cable.
Post removed 
mijostyn's avatar
mijostyn
8,164 posts
 
Then tvad they are not balanced. Pin 1 has a shorting contact to the XLR housing. There is no forth ground. The proper wire is three conductor. The forth wire is there I believe for powered microphones. Any interconnect without a proper shield is asking for it.
You hook the shield up to pin one and leave the third wire unused at both ends. You use a floating shield in power cables. You are floating it to prevent ground loops. 
Post removed 
auxinput
2,920 posts
 
The 4th wire is not for powered microphones.  Powered microphones use what is called "Phantom power".  This is DC voltage that is applied to the signal wires (pins 2 and 3).

The 4th connection on the XLR plug is connected to the equipment chassis/ground.  This can actually be different than Pin 1 signal ground (which is a common/shared ground for the analog circuits), but not necessarily a different connection on all equipment.
More to discover