The diaphragm is placed over the cup with a needle on the receiving side of the diaphragm. Liquid microphones, invented by Alexander Graham Bell and Thomas Watson, were among the first microphones worked on being developed, and they were the pioneers for what would later become condenser microphones.Įarly liquid microphones used metal cups filled with water and sulfuric acid. You only need a basic understanding of how they are unique and which one is best used in different situations. There are 10 common types of microphones in the industry, you don’t really have to know what the mechanics and science behind each type is. Let’s get right into it and see which wireless microphone frequency bands are legal. It should be noted that each type of microphone has a different way of converting its energy form, but they all have something in common, the diaphragm. What Wireless Microphone Frequency Bands Are Legal?