ribbon microphone
The ribbon microphone is an electrodynamic microphone. In this microphone, the diaphragm is an extremely light ribbon, only 2 mm to 4 mm narrow, which is located in a permanent magnetic field and is moved by the sound pressure. The movement of the diaphragm causes an induction in the ribbon, which results in a current flow. This is proportional to the sound velocity, i.e. the speed of the movement.
The current flow depends on the excursion of the ribbon and thus on the magnitude of the sound pressure. The ribbon is made of aluminum and has an extremely low mass, which can be less than 1 mg. The sensitivity of the ribbon microphone is relatively high and is about 1 mV/ Pa, which corresponds to a dB value of-80 dB. In addition, it is relatively sensitive to temperature and is not very robust.
However, it is characterized by superior acoustic properties and has a warm, natural sound. The wide frequency range of about 40 Hz to 18 kHz is ideal for use in concerts and high-quality audio recordings. The nominal impedance of ribbon microphones is 200 ohms. This is due to the fact that the actual ribbon impedance is only 0.2 ohms and the extremely low ribbon voltage must be transformed up by a factor of 30, which inevitably causes an increase in impedance.