The AT4055 is a large-diaphragm, pressure-gradient capacitor microphone with a uniform cardioid polar pattern. The frequency response is smooth over an extended 20-20,000 Hz range. Based on the same advanced technology used in 40 Series studio microphones, the AT4055 is the result of a dedicated effort by Audio-Technica to bring studio-quality sound to the stage. It is designed for use in the most demanding sound reinforcement and recording applications. The AT4055 is the culmination of extensive field evaluations in live-sound environments with resultant significant advances in microphone performance factors. It features very low self-noise, with a transformer-coupled output optimized for live-sound applications. An extended, flat low-frequency response adds extra body and depth to vocals, and highlights the performance of on-stage instruments. The AT4055 incorporates a specially-contoured large diaphragm that is aged through five different steps to assure the optimum characteristics achieved will remain constant over years of use. The 2-micron-thick, vapor-deposited gold diaphragm provides extremely smooth, warm and true-to-life reproduction of even the most subtle sonic nuances. The off-axis response of the AT4055 is linear and uniform across the entire frequency range of the microphone. Any off-axis sounds (leakage) remain accurate and lifelike, resulting in a much more natural vocal/instrument mix. For exceptional transient response and sound pressure level capability, the element back plate is precision-milled and aged to provide stable, optimum capacitance. The reductions in frequency response peaks and diaphragm distortion result in a microphone that delivers an articulate output even in very high sound pressure environments. To further enhance the on-stage performance capability, Audio-Technica engineers have employed a carefully-designed shockmount system to provide outstanding handling noise characteristics and mechanical shock resistance. In addition, the AT4055 element is protected by a hardened-steel windscreen. For even greater durability and protection, the element is housed in a second, internal windscreen, which also provides excellent resistance to popping. The microphone element is enclosed in a rugged housing with baked-on, low-reflectance black finish. The included AT8406 tapered stand adapter permits mounting on any microphone stand with 5/8"-27 threads