Altec 802D (1957–1972)
A high-frequency compression driver built for clarity and durability in demanding audio systems.
Overview
The Altec 802D is a high-frequency compression driver that Altec Lansing built from 1957 to 1972. It was made mainly to work with the company's 511 and 811 sectoral horns. In that role it was a key high-frequency component in two-way high-fidelity systems - the top half of a speaker that split the audible range at a single crossover point and left everything below to a big woofer.
What makes the 802D interesting is where it ended up. It was designed for large spaces with high ambient noise, the kind of venue where a system has to cut through a room full of people and still stay intelligible. But it also turned up in commercial loudspeakers meant for home listening, such as the Altec 832A, and over its production run it became a staple in Altec's lineup with widespread use in home audio systems. That dual life — professional tool that homeowners also bought — is the reason so many of them survive today in various states of repair.
Internally the 802D shares a nearly identical design with the Altec 804A. The main difference is magnet size and strength, and the 802D's magnet is the smaller, less powerful of the two. Both drivers use a 2¼-inch aluminum diaphragm, and both were built to sit on the same family of horns.
Altec's own advertising of the period leaned hard on the "Altec tradition" of faithful reproduction. It described the company's high-frequency horns as sectoral, exponential types that provide a clear, mathematically calculated flow path for the sound waves (Audio, November 1957, p.67). Elsewhere in the same period, Altec's literature described the 802D as designed specifically for use with the 511B and 811B horns (High Fidelity, October 1957, p.77). That's marketing language, but it shows how these drivers were conceived: as the front end of a matched horn-and-driver system, not as a standalone tweeter you'd bolt onto anything.
Key Features
2¼-Inch Aluminum Diaphragm
The heart of the 802D is its 2¼-inch aluminum diaphragm. Altec described the 802 as using an all-aluminum diaphragm. Aluminum is light, which helps the diaphragm start and stop quickly, and that's the reason these drivers have a reputation for transient response rather than warmth. The diaphragm is the part that actually moves and makes sound. Everything else in a compression driver exists to couple that motion to the air efficiently. A 2¼-inch diameter is large by modern tweeter standards, which is part of why the 802D crosses over so low - it can move enough air to meet a big woofer without straining.
Altec's literature notes that both the 802D and the related 806A use a voice coil of notably large diameter, edge-wound with aluminum ribbon and coupled to a large aluminum mechanical assembly. The transcription of that spec sheet is imperfect, but the intent is clear. This is a driver built around a substantial motor and a substantial diaphragm.
Designed for 511 and 811 Sectoral Horns
The 802D was engineered to work optimally with 511 and 811 type sectoral horns, and Altec's documentation pairs it specifically with those two horn families. The 511B pairing is the one that gets talked about most, and it's the combination that shows up in surviving systems. A compression driver and a horn are a matched set. The driver's throat has to mate to the horn's throat, and the horn's flare determines the coverage pattern and the low-frequency limit of the combination.
One boundary: Altec's own literature directs users to 730, 288, and 290 type drivers for multicellular horns. The 802D is not the driver for that job. It belongs on the two-way sectoral horns.
Magnet and Motor
The 802D uses an Alnico magnet - aluminum, nickel, cobalt - which was the standard magnet material in American speaker manufacturing before ferrite took over on cost grounds. Alnico is heavier and more expensive, and it behaves differently under heat and load than ferrite does. For a compression driver running at high efficiency in a horn system, that behavior is part of the sound.
The 802D and 806A magnets share the same inner and outer diameters, but the 802D has a longer body. Owners who've compared the two note that the 802 has a bigger magnet, which translates to higher SPL and higher sensitivity. That's the practical reason some listeners chase the 802D over the more common 806.
Rated Power and Crossover
Altec rated the 802D for 30 watts when used with an N-500E or N-800D network, and owner documentation corroborates it, stating both the 802D and 804A are rated for 30W. That sounds modest, but this is a horn-loaded compression driver with high sensitivity, and 30 watts into a horn system produces output that would take hundreds of watts from a direct-radiator speaker. The dividing network matters here. Altec's literature is explicit that these networks provide a smooth crossover from the low- to the high-frequency speaker and prevent low frequencies from damaging high-frequency drivers. Feed an 802D a full-range signal and you risk the diaphragm. Used with the correct network, it's a durable piece of gear.
Frequency response is listed at 500 to 22,000 cycles in Altec's spec sheet. The 500 Hz low end is the number that matters most, since it lets this driver meet a 15-inch woofer in a two-way system without a gap in the middle. Period documentation for the related dividing networks cites an 800-cycle crossover for use with the 811B horn and the 802D driver (High Fidelity, October 1957, p.77), and forum documentation states the spec sheet calls for crossover at 500 Hz with the N-500E network.
Historical Context
The 802D was designed primarily for use with 511 and 811 type sectoral horns, and it served as a key high-frequency component in two-way high-fidelity systems through its 1957-1972 production run. Altec's spec sheet for the driver is dated circa 1968, which puts it in the middle of that window.
Though it was intended for large spaces with high ambient noise, the 802D was frequently used in commercial loudspeakers meant for home listening, such as the Altec 832A. The same components that filled theaters and auditoriums were repackaged in furniture-grade cabinets for living rooms, and buyers got the professional driver rather than a domestic substitute.
The 802D also appears as a component in Altec's A7-500 Voice of the Theatre systems, where it's listed alongside the 416A woofer, the H-811B horn, and the N-800-E network. That's the canonical application: a two-way system with a 15-inch woofer on the bottom and the 802D on a sectoral horn up top. Owners have also pointed out an oddity. The 802 has a bigger magnet and higher sensitivity than the 806, yet the 806A sells more readily on the used market.
Collectibility & Value
Vintage 802D drivers are highly collectible, rated 8/10 on the vintage audio scale, and the driver remains a favorite in vintage speaker restorations and high-end retro builds. Rebuilt pairs have sold for $1,450 USD as recently as 2025.
Current asking prices on the used market are more mixed. Single drivers with an H-811B horn have been listed around $550, consecutive-serial-number pairs with original Altec diaphragms around $1,400, and single drivers in rougher cosmetic condition around $400. A complete A7-500 Voice of the Theatre system - the whole speaker, not just the driver - has been listed at $13,000, which is a system price rather than an 802D price. Recent sold listings tracked through price aggregators show a single 16-ohm driver around SGD 510 and a driver-plus-horn pair around $849.
Condition is everything, and the known failure modes are specific. Common issues include rust in the magnetic gap and stuck diaphragms, both consequences of age and storage rather than abuse. A stuck diaphragm usually means the gap has corroded or debris has migrated into it, and freeing it without damaging the diaphragm takes patience. Repairs typically involve replacement diaphragms from original sources or from Great Plains Audio, which has become the standard supplier for Altec diaphragm replacements. Parts units turn up too, sometimes with screws broken off in the cap holes.
Buying advice follows from the failure modes. Inspect the gap for rust before committing, check that the diaphragm moves freely, and confirm whether the diaphragm is original or a replacement. A driver with a clean gap and a known-good diaphragm is worth the premium over a cheaper unit of unknown history. Pairs with consecutive serial numbers carry a modest premium for collectors who care about matching.
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