The QTC Series (Quiet Time Coherent), which includes this matched pair of QTC40 small-diaphragm omnidirectional condenser mics, is designed for recording quieter sources such as vocals, strings and distant miked orchestras or choirs. These low-noise omnis are also an excellent choice for drum overheads, close-miked wind and percussion instruments. Earthworks' reputation for realism is based on these distinctive omnis. Time Coherent Response means these models do not smear the time domain as most microphones do.