Traditionally, quartz-control has been the basis for the design of wireless microphone systems. It's high level of stability under performance conditions and cost effectiveness allows users to enjoy an acceptable and affordable level of acoustic performance both for personal use and professional applications.

However, in today's audio industry, the demand for a higher number of simultaneous wireless channels is increasing. Though a quartz-controlled system has its unique advantages, today's professional systems require more sophistication. Today, professional systems need frequency agility (with the capability of changing frequencies quickly), more non-interfering channels and interference-free operation. A worldwide trend shows professionals are shifting away from quartz-controlled, single fixed-frequency systems to PLL (phase locked loop) synthesized systems.

PLL synthesized systems use a CPU to program and control various functions in the circuit of the wireless system. As a result, individual manufactures have developed systems that have their own unique functions and features, specifically designed to meet different operational demands. This gives more freedom of choice to users in the professional audio industry. Despite the fact that PLL synthesized system are more expensive than quartz-controlled systems, PLL is seen as the best technology in the industry today, due to its better acoustic performance and its multi-channel capability.