JBL 2441 Compression Driver (1981)

Name: JBL 2441 Compression Driver
Brand: JBL

The 2441 weighs over 11 kg and has a 4-inch aluminum voice coil driven by an Alnico V magnet that exceeds 10 kg. It is built like a block of cast metal.

Overview

The JBL 2441 Compression Driver came out in 1981. It was one of the last and most refined large-format JBL compression drivers before the industry moved to neodymium and titanium diaphragms. It sold for ¥145,000 per unit in Japan around its launch, and it was aimed at professional installations that needed reliability, power, and smooth high-frequency extension up to 18 kHz. It was built as a driver unit for sound reproduction in large halls and theaters. It evolved directly from the JBL 375 and shares its 4-inch voice coil and Alnico V magnet, but adds a computer-optimized phase plug and a diamond-pattern suspension diaphragm. Owners report a peak-free, extended response that holds up under punishing program material. That mattered in touring sound reinforcement and in flagship studio monitors like the 4355, 4344, and 4350, where it handled the midrange band from 500 Hz upward. The 2-inch throat (50.8 mm) fits JBL's professional horn systems, including the 2307/2308 bi-radial assembly. The big Alnico structure accounts for the weight, approximately 11.3 kg, and for its reputation for magnetic stability over decades of use. Collectors note the build quality borders on over-engineered, with edgewound aluminum ribbon voice coils and a die-cast housing that resists deformation even under high thermal load.

Key Features

4-Inch Aluminum Voice Coil with Edgewound Ribbon Construction

The 2441's 100 mm (4-inch) voice coil is among the largest ever used in a production compression driver. That gives it exceptional heat dissipation and power handling. The coil is aluminum ribbon wound on edge, which keeps mass low and surface area high for cooling. This lets it sustain high output without compression or distortion. The edgewound ribbon construction is confirmed in technical documentation. It supports a rated 70 to 100 watts of continuous program power, depending on the source, and operation at 500 Hz and above without thermal failure. Engineers at the time said the coil's geometry was optimized using laser holography and computer analysis, for linearity under extreme excursions.

Alnico V Magnet Structure Exceeding 10 kg

The 2441 has an Alnico V magnet assembly weighing over 10 kg. Catalog specifications report a magnetic flux density as high as 20,500 gauss. That stable, high-flux field contributes to the driver's efficiency and dynamic response. Alnico V is less prone to demagnetization over time than ferrite or neodymium, which is why owners report that vintage units rarely require recharging. The magnet's mass also makes the 2441 very heavy, so it needs sturdy mounting hardware. Installers learned that quickly when retrofitting older systems.

Aluminum Diaphragm with Diamond-Pattern Suspension

The 100 mm (4-inch) diaphragm is 0.08 mm aluminum with a diamond-pattern surround, a JBL design referred to as "diamond suspension." It differs from traditional roll or tangential edges and controls secondary resonances more effectively, giving a smoother, peak-free response up to 18 kHz. According to technical notes, the suspension offers reliability comparable to roll edges while improving linearity. Some users report that aftermarket titanium diaphragms are available but tend to "ring" and lack the tonal neutrality of the original aluminum unit. Enthusiast forums echo that and warn against substitutions.

Computer-Optimized Phase Plug for Smooth Response

JBL used computer modeling for the 2441's phase plug, a significant advance over earlier models. The plug's geometry was engineered to minimize diffraction and give even wavefront propagation into the horn throat, which reduces distortion and improves off-axis response. That contributed to the driver's reputation for clarity in both studio and live sound, where accurate midrange reproduction is paramount. The plug also supports the 500 Hz low-end crossover point recommended for professional use, for integration with mid-bass drivers in multi-way systems.

Historical Context

The 2441 is a direct evolution of the JBL 375. It shares the foundational architecture but refines the diaphragm and phase plug for smoother high-frequency performance. It was positioned as a professional-quality mid and high-frequency transducer, and it went into JBL's most prestigious systems, including the 4355 studio monitor, where it paired with the 2307/2308 horn, and large-format installations in cinema and sound reinforcement. Its 1981 release coincided with a period of transition in pro audio, as venues demanded higher output and reliability from PA systems. The 2441 met that need with brute-force engineering and acoustic precision, at a time when digital signal processing was still in its infancy. It was not as widely known as the 2405 slot tweeter, but it played an equally critical role in shaping the sound of high-end monitoring and live sound throughout the 1980s.

Collectibility & Value

Today the 2441 commands strong prices on the secondary market, with clean, working units regularly fetching $600 or more. Listings vary widely. A single vintage unit sold for $246, a New Old Stock pair reached $1,600, and a Japanese import pair listed at $1,698. A US Audio Mart listing in 2025 showed a model with an original 2445 titanium diaphragm at $425, which suggests component condition significantly affects value. Replacement diaphragms (D16R2441) are reported to cost over $200 each, so restoration is not cheap. Common maintenance includes diaphragm replacement after decades of use, cleaning the phase plug and throat, terminal inspection, and re-sealing the driver-to-horn interface to prevent air leaks. The 2441 was produced in both 8 Ω and 16 Ω versions, though the 16 Ω variant appears more commonly documented. Given its weight and mounting requirements, collectors stress proper hardware and secure installation. It remains a sought-after component for vintage monitor rebuilds and high-efficiency horn systems.