First of all, you need to decide on your requirement for the microphone set. If you require a microphone set for karaoke music you need to figure out what exactly the occasion is going to be. The occasion could be an outdoor concert or a school or college event. It could be a birthday party, wedding, School assemblies, conference meetings and so on. You would need to categorize your occasion under indoor or outdoor use. If you opt for an indoor occasion you can settle down with even lesser operating distance ranges. Here your distance range of operation could be 30 meters or up to 80 feet. However, if you are looking for something that can be used between a large crowd, then you need to go for a good distance range that can be covered by the microphone set. You can opt for 60 meters or up to 300 feet.