Dynamic And Condenser Mic Performance Compared Diagram S shows the operating principles of the two types of microphone design used in Sound Reinforcement (or Public Address). The more common of the two is the ‘dynamic’ mic, shown at the top. It is the cheaper of the two designs to manufacture, and is extremely robust. Unsurprisingly then, it is an exceptionally popular choice, especially when budget is a consideration. Dynamic mics are also very easy to understand, because the concept is basically the same as a loudspeaker but in reverse. However, the real-life engineering that goes into a dynamic mic is a lot more refined than the diagram implies. (No-one has really produced a mic that looks like a small woofer since about 1920!) Rather than a cone, a modern dynamic mic using a lightweight plastic diaphragm that looks a bit like a tweeter for a Hi-Fi speaker. No matter how light the material used to create the diaphragm, in a dynamic mic it still has to be coupled to the coil of wire that moves over a permanent magnet, thereby creating current. The added weight of that coil, and the former it sits on, is one of the reasons a dynamic mic can’t rival the high frequency response of a condenser mic. With mass comes inertia, meaning that the diaphragm becomes more resistant to movement as the frequency increases. To put it another way, as the air pressure changes faster and faster, the diaphragm assembly moves less and less. Let’s see how that compares to a condenser design.