Visual Sound, Inc. Medium-Format Horn MH640c

Electro-Voice The Electro-Voice® MH640C is a two-way, horn-loaded, speaker system for permanent installation. The mouth dimensions of both the mid-bass and high-frequency horns are perfectly designed and large enough - with respect to the wavelengths reproduced - that the MH640C can provide uniform directivity control down to 500 Hz. The superior directivity control of the MH640C increases speech intelligibility and musical clarity in difficult acoustic environments. Other horn systems with similar radiating areas cannot provide the high degree of directional control of the MH640C.The MH640C is a 60 degree x 40 degree, two-way system with coaxially mounted mid-bass and high-frequency horns. The horns' common acoustic axes ensure smooth response and coverage in crossover regions when appropriate signal delay is applied to the high-frequency driver. The high-frequency section delivers smooth and extended performance while operating from 1,600 Hz to 20,000 Hz, and consists of a specially developed, low-profile, DH2As2 compression driver coupled to an HP64 60 degree x 40 degree Constant Directivity horn.The HP64 features integral, fiberglass-and-zinc construction for exceptional strength and performance. Beamwidth-control vanes in the horn throat correct all coverage anomalies within a 10 kHz to 20 kHz octave. This horn-and-driver combination is securely mounted to the mid-bass horn by a heavy-duty steel bracket. The mid-bass system is composed of a DL10X-SH 10-inch (24.5 cm) reproducer mounted on a MH640 60 degree x 40 degree mid-bass horn. The DL10X-SH reproducer contains a Kevlar® and epoxy cone, which is twice as strong as a conventional paper cone. The mid-bass section operates between 140 Hz and 1,600 Hz, and features a proprietary, Aperiodic Enhancer™ phase plug (U.S. patent no. 4,718,517), which extends high-end output to blend seamlessly into the coaxial, high-frequency section.Kevlar® is a registered trademark of DuPont.