511B

About the 511B

The Altec 511B is an aluminum die-cast sectoral horn intended for midrange frequencies, typically crossed over at 500 Hz. It provides a uniform sound pressure distribution with a 90° horizontal and 40° vertical coverage pattern, making it suitable for theaters, halls, and high-fidelity audio systems. Compatible drivers include the Altec 802-8D, 806-8A, and 808-8A compression drivers. The horn is known for its wide diffusion characteristics and is often used in conjunction with other horns like the 811B for higher frequencies. It weighs approximately 17.75 pounds (8.05 kg) and measures about 10-5/8" (27.0 cm) in height, 23-5/8" (60.0 cm) in width, and 18-1/2" (47.0 cm) in depth. The 511B is highly regarded for its realistic playback and high sensitivity, making it a favorite among audiophiles who prefer low-power amplifiers and high-efficiency speakers. Drivers, dividing networks, and adapters are sold separately. The horn is considered a classic and is still sought after for restoration and custom speaker projects.