The lavalier cord may be hidden by clothes and either run to an RF transmitter in a pocket or clipped to a belt (for mobile use), or run directly to the mixer (for stationary applications).

The signal from the oscillator may either be amplitude modulated by the capacitance changes produced by the sound waves moving the capsule diaphragm, or the capsule may be part of a resonant circuit that modulates the frequency of the oscillator signal. As well as projecting the voice on the other end of the line, these speakers also include 360-degree microphones, so that everyone can get involved with the conversation. It's equipped with 4 microphones and Anker says a single PowerConf S500 "delivers performance for rooms of up to 12 people, and you can wirelessly pair two of them to increase coverage for up to 20 people. While you can connect your phone or computer via Bluetooth, you can also connect the speaker directly to your computer with a USB-C cable.Combining the multiple signals correctly is difficult; designs that do this are rare and tend to be expensive. I like how Jabra has redesigned the new models, giving them a sleeker, cleaner look, and all the models include an integrated USB-C cable with a USB-A adapter that allows you to plug the speaker directly into a Mac or Windows PC. Microphones containing active circuitry, such as most condenser microphones, require power to operate the active components. Power is necessary for establishing the capacitor plate voltage and is also needed to power the microphone electronics (impedance conversion in the case of electret and DC-polarized microphones, demodulation or detection in the case of RF/HF microphones).

Certain ribbon and dynamic microphones however are exceptions, due to the designers' assumption of a certain load impedance being part of the internal electro-acoustical damping circuit of the microphone. Increasing the thickness of the material improves wind attenuation but also begins to compromise high-frequency audio content. Close talking microphones may be measured with different sound sources and distances, but there is no standard and therefore no way to compare data from different models unless the measurement technique is described.Crown's trademark on this approach is Phase Coherent Cardioid or PCC, but there are other makers who employ this technique as well. A downside to impedance matching is the 6dB loss in signal that occurs as only half the voltage level appears at the pre-amplifier's input. The externally applied charge used for a conventional condenser microphone is replaced by a permanent charge in an electret material. When not concerned with power transfer, signals are generally transferred as varying voltages and this is also the case for microphones.