Altec Lansing 291-16A / 291-16B (1970–1975)

At 9.1 kilograms and 18,500 gauss, this driver is built to be loud.

Overview

The Altec Lansing 291 series is not a bookshelf speaker. It is a compression driver built for theater and industrial sound, where 131 dB SPL at 40W is the baseline. The 291-16A came first, in 1970. The higher-powered 291-16B followed in 1975. Both are 16-ohm drivers made to run large horns in high-output rooms. They weigh just over nine kilos each. The core design is about efficiency: a flat aluminum ribbon voice coil wound edge-wise, a big alnico magnet structure producing 18,500 gauss, and a voice coil diameter of 7.1cm that leaves plenty of thermal and mechanical headroom.

The 291-16A and 291-16B look alike, but they are not identical. The later 291-16B doubles the power handling to 80W and rolls off at 14 kHz, against the 16A's 16 kHz upper limit. Both share the same 500 Hz lower crossover point and are rated at 117 dB/W/m sensitivity, which makes them efficient partners for large horn systems. Owners report using them with Altec's own 311-90, 311-60, and 329A horns, often with N-500F networks or custom crossovers. The 291-16A launched with a Symbitik diaphragm, a hybrid of polymid film and aluminum alloy derived from the 288D, promising wide bandwidth and sharp transient response. Collectors note that Altec also offered a more durable, less sonically refined diaphragm for high-power applications. So there were two flavors: one tuned for fidelity, the other for endurance.

The 291s never reached the cult status of the 288 series. Some forum discussions suggest they offered little sonic advantage over the 288 beyond more power handling, which made them a niche choice even in their prime. Many surviving units still turn up with original diaphragms and intact lead-ins, though the fragile internal conductors remain a known weak point.

Specifications

Key Features

18,500 Gauss Alnico Magnet Structure

At 18,500 gauss, the alnico magnet gives intense flux density and tight control over the voice coil at high excursions. That is about linearity under load as much as loudness. The field strength contributes directly to the driver's 117 dB/W/m efficiency and its ability to sustain 131 dB SPL without compression. Alnico's smooth saturation characteristics also help avoid the harshness that can creep in with ceramic magnets at high drive levels, which gave the 291 a reputation for clean, dynamic output with the right horn.

Symbitik Diaphragm with Polymid-Aluminum Composite

The 291-16A debuted with a Symbitik diaphragm, a composite of polymid film and aluminum alloy. The hybrid construction aimed to combine the rigidity of metal with the damping of polymer, reducing breakup modes and extending high-frequency response to 16 kHz. The design was derived from the 288D, but tuned for higher power. Owners report Altec also supplied a more durable, sonically duller diaphragm for high-power installations, a trade-off between longevity and fidelity. The OEM diaphragm part number 21531 remains available as NOS stock.

Edge-Wound Flat Aluminum Ribbon Voice Coil

The voice coil is flat aluminum ribbon, wound edge-wise around a 7.1cm former. It is a hallmark of Altec's high-power engineering. Compared to round wire, this design adds surface area for better heat dissipation and reduces mass, which improves transient response. Combined with the large magnet gap, it lets the 291-16B handle 80W, twice the input of many contemporaries. The coil's construction also contributes to the driver's deep 124-126mm profile.

Reinforced Lead-In Wires (and Their Failure Modes)

One of the most commonly reported failure points is the lead-in wires—thin, stiff conductors that connect the voice coil to the terminal. Over time and thermal cycling, these can fatigue and break, especially near the coil attachment. Forum posts confirm this as a widespread issue, prompting later re-engineering in successor models. Repair is possible but delicate, often requiring disassembly and careful splicing. The fragility underscores that while the 291 was built for power, it wasn’t immune to the material limits of its era.

Historical Context

The 291-16A emerged in 1970 as part of Altec's push into high-power cinema and public address systems. The 291-16B followed five years later with doubled power handling, reflecting growing demand for louder, more reliable sound reinforcement. The 291 series appears to have occupied a narrow niche. Some owners suggest it offered little sonic improvement over the more celebrated 288 series, with the primary advantage being increased power tolerance. That may explain its lower profile in audiophile circles.

Collectibility & Value

Current market prices vary widely based on condition and variant. A 291-16A listed as "original excellent" fetched CA$2,250 on Canuck Audio Mart, while another sold for $1,425 on PicClick.ca. The rarer 291-16K variant appeared at $225, which suggests significant model-specific differences in value. NOS diaphragms (OEM 21531) are available from private sellers, which matters given the known lead-in wire failures. No official data on common maintenance issues exists, but community knowledge emphasizes inspecting the internal conductors before purchase. There is no modern equivalent.

eBay Listings

ALTEC Original 25884 Diaphragms for 288/291/299 Series Pair

$860

Altec 291-16A 16-ohm Open Box - Very Nice Single

$1,200

ALTEC LANSING 291-16C 16-ohm DRIVERS Pair Nice Consecutive

$1,000

ALTEC LANSING 291-16C DRIVERS -PAIR

$1,000

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