Altec 811B Horn

A cast aluminum sectoral horn used in high-efficiency speaker systems, known for its distinctive horn sound and 90° x 40° dispersion.

Overview

The Altec 811B is a sectoral horn manufactured by Altec Lansing Corporation, primarily recognized as a component in larger speaker systems like the 820C Corner Speaker System. It was also used with the Altec Lansing Valencia consumer speaker, paired with the 806 compression driver. Though no standalone production years or model history are documented, the horn remains a sought-after part among vintage audio enthusiasts for its role in classic high-efficiency designs.

Specifications

Dimensions	476mm wide x 219mm high x 343mm deep
Dispersion	90 x 40
Lower reinforcement limit	800 cycles
Throat size	1"
Power Handling (System)	20–50W RMS (driver-dependent)
Sensitivity	≈ 96–98 dB

Design

The Altec 811B is constructed from cast aluminum with an exponential expansion profile. It is known to resonate audibly—"ring like a bell"—if not securely mounted to a proper bass enclosure, a characteristic noted by users. While the original 811 from 1952 was a one-piece casting with mouth fins, specific construction details for the 811B variant are not fully documented.

Context

The H-811B sectoral horn was integrated into the Altec 820C Corner Speaker System and used with the Altec Lansing Valencia speaker. Its design supports high-efficiency sound reproduction and has made it a favorite in vintage horn audio builds, particularly among those replicating classic systems like the Model 19.

Market

Vintage Altec drivers and speakers are highly prized by collectors, and the 811B horn is no exception. It has been listed for sale at $275 for a pair, indicating continued interest in the used market. One common issue is mechanical resonance, which users have mitigated by wrapping the horn to reduce vibration.