Altec Lansing 938 1-Inch Compression Driver

The Altec Lansing 938 is a high-efficiency compression driver produced during the mid-20th century, widely recognized for its use in professional sound reinforcement, studio monitoring, and high-fidelity home audio systems. Known for its robust construction and dynamic sound, the 938 was a staple in many iconic audio setups and remains a sought-after component among vintage audio enthusiasts and horn speaker builders.

Specifications

Parameter	Specification
Driver Type	1-inch exit compression driver
Impedance	16 ohms
Sensitivity	Approximately 110 dB
Diaphragm Material	Aluminum (standard), phenolic (some variants)
Voice Coil Size	1-inch
Frequency Response	1.5 kHz – 18 kHz (typical when horn-loaded)
Power Handling	Unknown (estimated 25–50W short-term)
Recommended Horns	Altec 811, 511, or equivalent exponential horns
Mounting Pattern	Standard 4-screw compression driver mount
Weight	~1.2 kg (2.6 lbs)

Historical Context

The Altec Lansing 938 emerged during the golden era of professional audio, a time when Altec Lansing dominated the landscape of theater sound, broadcast studios, and high-end home audio. As part of Altec’s renowned driver lineup, the 938 was engineered for high efficiency and reliability, making it ideal for use in horn-loaded systems that demanded clarity and output at minimal amplifier power.

Frequently paired with classic horns like the Altec 811A or 511C, the 938 contributed to what audiophiles describe as the "West Coast sound"—a bright, articulate, and dynamic sonic signature that contrasted with the warmer "East Coast" voicing of other manufacturers. These systems were commonly found in movie theaters, live sound setups, and high-fidelity listening rooms throughout the 1950s to 1970s.

Though the exact production years of the 938 are undocumented, its design and construction align with Altec’s manufacturing practices of the 1960s and early 1970s. It shares lineage with other legendary drivers like the 285 and 802, and its influence can be heard in vintage sound systems that remain operational today.

Sound Signature

The Altec 938 delivers a bright, detailed, and highly dynamic high-frequency response with a strong midrange presence. When properly mated to a compatible horn and crossover, it offers exceptional clarity and projection. However, due to its high efficiency and forward character, it can sound harsh or fatiguing if mismatched with darker-sounding low-frequency drivers or poorly designed crossovers.

Its aluminum diaphragm versions tend to be more aggressive and extended in the upper frequencies, while models equipped with phenolic diaphragms (a less common variant) exhibit a slightly smoother, more balanced top end—making them preferable for critical listening applications.

Maintenance and Restoration Tips

Like all vintage audio components, the Altec 938 benefits from careful inspection and maintenance, especially if used regularly:

Diaphragm Inspection: Check for tears, warping, or oxidation. Aluminum diaphragms can corrode over time, particularly in humid environments. Replacement diaphragms and repair kits are available from specialty audio restoration suppliers.

Terminals and Wiring: Clean the binding posts and inspect internal wiring for brittleness or corrosion. Re-terminating with modern leads can improve reliability.

Magnet Strength: Older units may suffer from magnet degradation, reducing efficiency and sensitivity. Remagnetizing services are available and can restore original performance.

Horn Matching: Use with appropriate horns (e.g., Altec 811A) to ensure proper loading and frequency response. Mismatched horns can lead to poor dispersion and distortion.

Crossover Considerations: Pair with a well-designed crossover (typically 1.5 kHz or higher) to protect the driver and optimize integration with woofers.

Collectibility and Market Value

The Altec Lansing 938 holds a collectibility rating of 7/10 among vintage audio enthusiasts. While not as rare as some of Altec’s more exotic drivers, its proven performance and historical significance ensure steady demand.

Market Value: $100–$300 per driver, depending on condition, originality, and diaphragm type.
Higher Value: Units with original phenolic diaphragms, clean cosmetics, and verified performance command premium prices.
Restoration Potential: Even non-working units can be valuable for parts or restoration projects.

Conclusion

The Altec Lansing 938 remains a classic example of mid-century American audio engineering—designed for durability, efficiency, and sonic impact. Whether used in a restored theater system, a vintage horn speaker project, or a high-efficiency home audio setup, the 938 continues to deliver a compelling and authentic listening experience that captures the spirit of a bygone audio era.