mid-range driver, and, as claimed by inventor Dr. Earl Geddes, mitigate higher order modes, a form of phase and amplitude distortion. The practical limitation of horn length is explicitly not addressed by the theory of OSWG. Applications Public address and concert use Horn loudspeakers are used in many audio applications. The drivers in horn loudspeakers can be very small, even for bass frequencies where conventional loudspeakers would need to be very large for equivalent performance. Horn loudspeakers can be designed to reproduce a wide range of frequencies using a single, small driver; to some extent these can be designed without requiring a crossover. Horn loudspeakers can also be used to provide the very high sound pressure levels needed for sound reinforcement and public address applications, although in these high sound pressure applications, high fidelity is sometimes compromised for the sake of the necessary efficiency, and also for the controlled dispersion characteristics which are generally required in most large volume spaces. "Gunness Focusing", a new method of counteracting some of the horn distortions, especially in the time domain, was pioneered by Dave Gunness while he was with Eastern Acoustic Works (EAW). EAW horn-loaded loudspeakers that have been processed with this proprietary system show reduced compression driver diaphragm/phase plug time-smear distortion while retaining high output power and controlled dispersion. Concert venues often use large arrays of horn loudspeakers for high-volume bass reproduction ("bass bins" or subwoofers), in order to provide bass that concertgoers can not only hear but feel. Combining multiple horn loudspeakers in an array affords the same benefits as having a single horn with a greater mouth area: the low frequency cut-off extends lower as the horn mouth gets larger, and the array has the greater output power of multiple drivers. Commercial theaters Commercial cinema theaters often use horn-loaded loudspeakers for pattern control and increased sensitivity needed to fill a large room. Audiophiles and home use Consumer audio employs horn loudspeakers for controlled directivity (to limit audio reflections from room surfaces such as walls, floor, and ceiling) and for greater speaker sensitivity. Horn loudspeakers can provide very high efficiencies, making them a good match for very low-powered amplifiers, such as single-ended triode amps or other tube amplifiers. After WWII, some early hi-fi fans went so far as to build low frequency horns whose mouths took up much of a wall of the listening room. The throats were sometimes outside on