What is the best cord for the SM58 and Prologue 12H?
This is an excerpt from: Microphone Techniques for Music - Sound Reinforcement
The output impedance of a microphone is roughly equal to the electrical resistance of its output: 150-600 ohms for low impedance (low-Z) and 10,000 ohms or more for high impedance.(high-Z). The practical concern is that low impedance microphones can be used with cable lengths of 1000 feet or more with no loss of quality while high impedance types exhibit noticeable high frequency loss with cable lengths greater than about 20 feet.
The proper cable for an SM58 or Prologue 12H will be based on the type of equipment to which you are connecting the microphone.