Altec 291-16B
At 3.5 pounds, it’s no lightweight—and when paired with the right horn, it can hit 129.5 dB from just one watt.
Overview
The Altec 291-16B is a high-frequency compression driver built for serious sound reinforcement, not delicate audiophile tinkering. Weighing in at approximately 3.5 lbs (1.6 kg), this is a big-format 1.4-inch driver designed to push serious air when mated to large-format horns. Collectors and restorers alike note that original units with intact diaphragms are increasingly rare—so rare that one listing explicitly stated, “Original Diaphragms SOLD,” signaling just how tightly held those parts have become. While not Altec’s top-tier HF driver (that distinction often goes to the 288-16G), the 291-16B still commands respect for its robust build and high output potential. It was clearly engineered for durability and efficiency, with a 2.8-inch voice coil contributing to its substantial physical presence and thermal handling. Despite its age, it remains a sought-after piece for vintage PA restoration and high-efficiency speaker builds.
The driver’s performance is heavily influenced by the horn it’s mounted to, and the fact sheet data shows a clear pattern: with horns like the 311-60 and 203B, output peaks at 129.5 dB at 4 feet on 1 watt, making it one of the more efficient configurations documented. At 10 feet, that drops to 121.5 dB, and at 30 feet, 112.0 dB—still extraordinarily loud for a single watt. The 311-90 and 1003B horns yield slightly lower output, topping out at 126.0 dB at 4 feet. This variation underscores a key truth for users: the horn is not just an accessory, it's a core part of the system’s acoustic identity.
Specifications
| Manufacturer | Altec |
| Product Type | Compression driver |
| Power Handling | 40 watts |
| Impedance | 16 ohms |
| Weight | Approx. 3.5 lbs (1.6 kg) |
| Voice Coil Diameter | 2.8 inches |
| Sensitivity | 110–112 dB (1W/1m) |
| Sound Pressure Level (SPL) | 129.5 dB at 4 ft (1.2m) with 311-60 horn, 1W input |
| Sound Pressure Level (SPL) | 121.5 dB at 10 ft (3m) with 203B horn, 1W input |
| Sound Pressure Level (SPL) | 111.0 dB at 30 ft (9m) with 803B horn, 1W input |
| Gasket Specification | No. 1 to No. 3 for 288-16G, 291-16B, 290E |
Key Features
2.8-Inch Voice Coil for High Power Handling
The 2.8-inch voice coil is a standout mechanical feature, contributing to the driver’s ability to handle sustained high-power signals without thermal failure. This large coil diameter supports the rated 40-watt power handling and likely contributes to the driver’s ability to remain stable under load. While some sources claim higher power ratings—up to 50W RMS or even 80W—those figures are unconfirmed and conflict across less authoritative sources. The 40-watt figure from audio-database.com remains the only consistently cited spec without contradiction, and thus is presented as the baseline. The coil size also suggests a design prioritizing durability over ultra-fast transient response, aligning with its use in live sound rather than critical studio monitoring.
16-Ohm Impedance for Parallel Configurations
The 16-ohm impedance makes the 291-16B well-suited for installations where multiple drivers are wired in parallel without overloading amplifiers. This was a common design choice in professional audio systems of the era, allowing for scalable arrays while maintaining safe load levels. The impedance is consistent across all verified sources, with no conflicting data, making it a reliable specification for system integration. Users building multi-driver cabinets will find this impedance particularly useful when planning crossover networks and amplifier matching.
High Sensitivity with Horn-Dependent Output
With a sensitivity range of 110–112 dB (1W/1m), the 291-16B is an exceptionally efficient driver. However, its real-world performance is best understood through the provided SPL measurements with specific horns. When mounted on either the 311-60 or 203B horn, it achieves 129.5 dB at 4 feet on just one watt—louder than most rock concerts at stage side. Even at 30 feet, output remains high at 112.0 dB with those horns. This level of efficiency made it ideal for large venues before the era of high-powered solid-state amplifiers. The drop-off with the 311-90 and 1003B horns (126.0 dB at 4 feet) suggests a trade-off in directivity or throat coupling, but still places it among the most efficient vintage HF drivers available.
Collectibility & Value
The Altec 291-16B is considered hard to find, especially in original condition with intact diaphragms. A December 2025 listing on US Audio Mart priced a single unit at USD $800.00, while earlier listings show a pair offered for $950 OBO in 2021 and a single unit at $675 in 2022 on DIYAudio. These fluctuations suggest a niche but active market, driven by restorers and vintage PA enthusiasts. A recent listing included the condition note: “Original Diaphragms SOLD”. Like all vintage electrodynamic drivers, the 291-16B requires careful inspection before purchase—creaky surrounds, corroded terminals, or damaged diaphragms can render it unusable without expert repair. Factory replacement parts are noted to exist, but availability is not confirmed.
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