Altec 511A (c. 1960s–1970s?)

A sectoral horn designed for high-frequency reproduction in professional and high-fidelity audio systems.

Overview

The Altec 511A is a sectoral horn made by Altec. It was used with specific drivers and crossover networks to build high-performance loudspeaker systems. The available research doesn't document exact production years. Its association with the 808-8A and 807-8A drivers places it in Altec's mid-20th century professional audio lineup. It was engineered for both studio and high-fidelity use, often paired with Altec drivers and N-series networks for extended high-frequency response.

Specifications

Type	Sectoral horn
Frequency Response (with driver and network)	500 to 20,000 Hz or 500 to 22,000 Hz
Crossover frequency	500 Hz

Design

The 511A is a sectoral horn. That design gives controlled directivity and efficient high-frequency dispersion when mated with compatible compression drivers.

Context

The 511A shows up in documentation alongside the 511B, 511E, 802, 804, 806, and VOTT. That suggests a broader family of Altec horns used in modular speaker systems. It was commonly used with Altec drivers like the 808-8A and crossover networks such as the N501-8A or N-500E to make complete loudspeaker enclosures.

Market

The Altec 511A is still available on the vintage market, often described as a matching pair and noted as part of tested, functional vintage systems. One listing includes the horn paired with a 730C driver, labeled as tested and clean.