Altec 1003B

At 14.5kg and nearly a meter wide, this horn is big and loud, and it doesn't pretend otherwise.

Overview

The Altec 1003B is a multi-cell horn made for high-output sound reinforcement in large spaces. It was intended for theaters, concert halls, and outdoor public address systems, where clarity and volume over distance were required. The design favors controlled dispersion and efficiency, and it was a staple in professional installations during its era. The faceplate is wide and segmented, built from ten individual cells in a 2x5 configuration. Each cell channels sound in a tight, directional pattern. There is no consumer polish here. Every dimension and angle has an acoustic job, and decor isn't one of them.

Owners report that the 1003B hits hard when paired with appropriate drivers, particularly the 288-series and 290/291 variants. Horizontal dispersion is 90 degrees and vertical coverage is 35 degrees. That gives focused projection across wide but not very tall listening areas, like theater seating or open-air stages. Unlike modern horns that try to cover a broad frequency range, the 1003B works as a mid-to-high frequency device and crosses over at 300Hz. You need capable low-frequency speakers underneath it to get a complete system. The horn takes different throats - model 30210 for a single driver and 30170 when two drivers are used - which gives installers some flexibility in output and redundancy.

Despite its professional roots, the 1003B has found a second life with vintage audio enthusiasts and DIY speaker builders. It has a reputation for durability and raw output, and it's a prized part in retrofitted systems, especially with classic Altec drivers. Because of its size and directional behavior, it isn't suited for domestic living spaces unless they are acoustically treated or it goes in a dedicated listening room. The horn itself has no active electronics or crossover components. It is a passive acoustic transformer, and the driver and external filtering define how it performs.

Specifications

Manufacturer	Altec Lansing
Type	Multi-cell horn
External dimensions	Width 965 x Height 409 x Depth 648 mm
Weight	14.5kg
Directional property	Horizontal : 90 ° Vertical : 35 degrees
Crossover frequency	300Hz
Throat diameter	36mm
Cell Configuration	2x5
Applicable throat	30210 (1 Driver) 30170 (2 Drivers)
Impedance	16 ohms
Sensitivity	110 dB (1W/1m)
Frequency Response	1.5 kHz
On-Axis sound pressure level obtained by combination of horn driver	Horn: 1003B, DRIVER: 288-8G/288-16G, Input power: 15watts / 1watt, SPL at 30Ft.(9m): 104.5dB / 92.5dB, SPL at 10Ft.(3m): 114.0dB / 102.0dB, SPL at 4Ft.(1.2m): 122.0dB / 110.0dB
On-Axis sound pressure level obtained by combination of horn driver	Horn: 1003B, DRIVER: 290E/290-4G, Input power: 100watts / 1watt, SPL at 30Ft.(9m): 109.0dB / 89.0dB, SPL at 10Ft.(3m): 118.5dB / 98.5dB, SPL at 4Ft.(1.2m): 126.5dB / 106.5dB
On-Axis sound pressure level obtained by combination of horn driver	Horn: 1003B, DRIVER: 291-16B, Input power: 40watts / 1watt, SPL at 30Ft.(9m): 108.5dB / 92.5dB, SPL at 10Ft.(3m): 118.0dB / 102.0dB, SPL at 4Ft.(1.2m): 126.0dB / 110.0dB

Key Features

Ten-Cell Multicellular Horn Design

The 1003B has a 2x5 cell configuration, which makes it a ten-cell multicellular horn. The segmentation gives precise control over dispersion, minimizes reflections, and keeps coverage even across the intended listening area. Each cell acts as its own waveguide, which helps the horn stay clear at high sound pressure levels. The design is tuned for professional environments where consistent off-axis response matters, such as auditoriums or outdoor venues, where a single speaker has to cover a wide audience without hotspots or dropouts.

Interchangeable Throat System for Single or Dual Drivers

The 1003B can be set up for one or two driver units by swapping the throat adapter. The 30210 throat supports a single driver, which keeps smaller systems simple. The 30170 allows dual-driver setups for more output and redundancy. That made the 1003B versatile across installations, and engineers could scale performance to venue size and power requirements. The 36mm throat diameter fits a range of Altec compression drivers, though alignment and sealing have to be right to avoid distortion or air leaks.

High Sensitivity and Long-Throw Output

The 1003B is rated at 110 dB sensitivity (1W/1m), which is very efficient. It converts electrical input into acoustic output with minimal loss. Driven by units like the 290E or 291-16B, it reaches SPLs above 126 dB at close range (4 feet). That suits long-throw applications where sound has to travel significant distances without an amplification boost. High efficiency and directional control mean fewer units are needed to cover large areas, which reduces system complexity in professional deployments.

Collectibility & Value

The Altec 1003B is sought after among vintage PA collectors and high-efficiency speaker enthusiasts. Individual units have appeared on the market labeled “Parts Only” at prices as high as $4,000, reflecting scarcity and demand. A listing on Reverb offered a pair for £392.48. Another sale included a matched pair of horns with Altec 291A-16 drivers and an 80210 adapter, which suggests complete systems command premium interest. No widespread structural failures or common maintenance issues are documented, though the horn surface and throat threads should be checked when buying used units.