Western Electric 594A (1933)

A field coil compression driver bolted to a horn, from the early days of cinema sound.

Overview

The Western Electric 594A is not something you pick up at a flea market. It's a field coil compression driver, built for theaters and not living rooms. It was part of Western Electric's second-generation Mirrophonic systems, the ones that filled movie palaces when "talkies" were still a novelty. It is best paired with a horn like the ES290 Biradial No.1955. Owners report a smooth, effortless midrange. One reviewer put it plainly: "You can truly hear the quality and smoothness - even over the poor 16 bit camera mic!"

And let’s be clear—this isn’t some forgotten prototype. The 594A has a cult that borders on reverence. On forums, you’ll find audiophiles calling it “the BEST compression driver ever made,” not with hyperbole, but with the quiet conviction of someone who’s heard it. It’s the kind of gear that becomes a reference point, not just for sound, but for what’s possible when engineering isn’t chasing cost targets. As one collector put it: “it is good to have those Western Electric sounds cataloged in my head as a reference library.” That says more than any spec sheet ever could.

Specifications

Manufacturer	Western Electric
Product type	Field coil compression driver
Field coil resistance	17.5 ohms (tested)
Voice coil resistance	13 ohms (tested)
Approximate dimensions	17 x 21 x 23 cms
Weight with packing	20 kgs

Key Features

Field Coil Magnet System

The 594A uses a field coil magnet, not a permanent magnet, so it needs external DC power to energize the magnetic field. Field coils were the high-end solution in the 1930s, offering stronger, more stable magnetic fields than early permanents, which meant tighter control and lower distortion. They are also a pain to integrate today. You need a power supply, wiring, and patience. Owners who went through the trouble say it was worth it. The driver tested in one account was described as "all original," and that matters, because corrosion, degraded windings, or replaced parts can ruin a field coil driver fast.

Compression Driver Design

A compression driver doesn't move air directly. The 594A pressurizes a small chamber behind a diaphragm and sends the sound through a narrow throat into a horn. That gives high efficiency and directivity, which you need when you're filling a 2,000-seat theater with dialogue and music. The throat diameter of the compatible ES290 Biradial horn is 2.000" (50.80mm), though the driver itself doesn't have a published throat spec. Unlike later Altec designs that leaned on brute force, the 594A is said to deliver its power with refinement.

Historical Context

The 594A was part of Western Electric's second-generation Mirrophonic systems, an effort to dominate cinema sound. These were not home units. They were installed in real theaters as part of a complete system. But the run was short. As one account puts it: "They were only out for two years or so before WE abandoned the theater business." That abrupt exit is a big reason these drivers are so rare today. The longer-lived 555 became a staple, while the 594A was here and then gone. Altec would later rise as a competitor in professional sound, but in the early 1930s, Western Electric was the benchmark.

Collectibility & Value

Don't expect a bargain. The 594A is "famous and scarce," and "far more scarce than 555 drivers," according to collectors. One user paid $500 for a 594A in 1989, a hefty sum at the time. As one owner put it: "the price is nuts but there is BIG money chasing this stuff." Another called it "definitely the sport of kings." Finding one "all original" is hard. No recent sale prices are documented. Restoration is possible, but once the field coil is compromised, the original output is gone.