The Simcenter Testlab Qsources Low Mid Frequency Source is an acoustic excitation device with an internal real-time volume sensor. At frequencies below 150 Hz, the source is omnidirectional and diffraction from the enclosure is negligible. In the mid-frequency range, the source mimics the acoustic characteristics of a human and acts as an omnidirectional source located at the position of the ear. The frequency range is between 10 and 1000 Hz.