Microphone cables come in several varieties for different needs.
Microphone cables are an important factor in the audio quality created when using a microphone. The type of cable you'll need depends both on how you'll be using the microphone and on what type of microphone you're using. Different cables are necessary for small lapel microphones (lavalier mics), high-impedance mics for casual use, and high-quality low-impedance mics for professional use.
Low-Impedance Microphone Cables
Impedance is a technical term for the amount of resistance to electrical current. A low-impedance microphone consequently provides less resistance to the signal passing through it. This aspect is why these cable types are preferred for professional applications. The lower the impedance, the more signal passes through the cable. However, more signal may also mean more signal noise, which is a common deficiency in these types of microphone cable. This problem is addressed by the shielding, or insulation, that is wrapped around the signal wires inside the outer protective material of the cable. The best shielding overall is known as the braid-type, which provides a greater protection against ambient signal noise becoming mixed in with the source signal passing through the cable. Low-impedance microphone cables with braid shielding and 3-pin XLR plugs are among the best types of microphone cables available.
High-Impedance Cables
High-impedance microphone cables have their place, although it’s not usually in a professional setting. This is due to the higher signal noise potential of these types of cables. The advantage is that a microphone with a high-impedance cable can be plugged directly into a variety of power sources, such as guitar amplifiers and lower-priced audio mixers. This provides flexibility and affordability for those who may not own or have access to a low-impedance mixer. Some adaptors are made to match a high-impedance microphone signal to a low-impedance mixer input, making them a valuable accessory for those who use high-impedance microphones and cables. It is important to use a shorter cable for high-impedance microphones to avoid unwanted, extraneous signal noise.
Balanced and Unbalanced Microphone Cables
The balancing of the signal in a microphone cable refers to the amount of positive and negative current flowing through the cable. An unbalanced cable generally has just one signal wire inside wrapped with shielding or insulation. The design theory is to reduce noise emitted by radio frequencies or other external sources from mixing in with the source signal moving through the microphone cable. However, this theory will not hold in most cases, even with high-quality braided shielding. This is because both the positive and negative currents are flowing through the same signal wire, thus creating the potential for more signal noise. A balanced cable has two separate wires inside, one for each of the current factors (positive and negative). Although the opposing currents are running in the same direction within the same cable, the noise is kept to a minimum because they are separated and because the voltage is matched. The addition of a tightly-wrapped braid-type shielding further reduces the signal noise, acting like an antenna to pick up the noise and keep it out of the cable.
Tags: signal noise, more signal, positive negative, through cable, cable However, cables important, flowing through
