Bozak B-302 (1957–1971)

Name: Bozak B-302
Brand: Bozak

At 45.5kg, it arrives with a warning.

Overview

The Bozak B-302 is more precisely the B-302A. Service manuals, collector forums and vintage listings all call it that, though people sometimes say B-302 informally. It is a three-way, four-driver floorstanding speaker system, introduced in various forms from at least 1957 through the early 1970s. One restored unit dates to 1957. Another pair carries a 1971 badge. That suggests a long production run, but exact start and end years remain undocumented. It was priced around ¥260,000 per unit in the late 1970s, which put it in a high tier among medium-sized systems of its era, according to available documentation.

The B-302A is an evolution of the B-300, with a dedicated midrange driver and a revised crossover network added. That is not a minor tweak. It changed how Bozak handled the vocal and instrumental midband, aiming for greater clarity there. The speaker combines the deep, controlled bass of a large sealed cabinet with more precision in the middle frequencies. Owners report a sound that is both authoritative and articulate, and one says it delivers "the cleanest bass" they've heard from a system of its size.

Specifications

Manufacturer	BOZAK
Model	B-302A
Product type	3-way speaker system
Model Rating Method	3-Way, 4-Speaker, Sealed Type, Floor Type
Frequency characteristic	40 Hz to 20 kHz
Impedance	8 Ω
Rated input	50W (MUSIC)
Crossover frequency	800 Hz, 2.5 kHz (6dB/oct.)
External dimensions	Width 600 x Height 765 x Depth 500 mm
Weight	45.5kg
Units Used	For Low Band : 30 cm Cone Type (B-199A); For Middle Range : 16 cm Cone Type (B-209B); For High Range : 5 cm Cone Type x2 (B-200Y); Other : N-10102
Driver configuration	Three-way, four-driver
Cabinet design	Sealed (acoustic suspension)

Key Features

30cm Cone Woofer with Variable Density Paper Diaphragm

The B-199A 30 cm cone woofer handles the bass. Its diaphragm is a felted paper composite with wool blended into the pulp, made with a variable density system. The cone is densest at the center and thins gradually toward the outer edge. The idea is to control breakup modes and give more linear, piston-like motion. In practice, this contributes to the speaker's reputation for clean, articulate bass, even at higher volumes. The sealed cabinet trades efficiency for tighter low-end response.

16 cm Mid-Range Driver with Aluminum-Neoprene Sandwich Diaphragm

The B-209B 16 cm midrange driver is what separates the B-302A from the B-300. Its diaphragm is a thin sheet of aluminum sandwiched between two layers of neoprene rubber film, with a stepped profile at the center and periphery. The aim is to combine the lightness and speed of aluminum with the damping of rubber, reducing coloration and resonance in the vocal range. Collectors note that this driver was a significant step forward in Bozak's pursuit of midband transparency.

Dual 5 cm Cone Tweeters with Foam-Damped Metal Diaphragms

Two B-200Y 5 cm cone tweeters handle the high frequencies. They are not conventional dome tweeters. They use a metal diaphragm mounted on a foam rubber platform, which helps dampen spurious vibrations and resonance. For frequencies above 10 kHz, the system relies on a 2 cm aluminum center dome integrated into the tweeter, based on the principle that cone diameter must not exceed the wavelength of the highest reproduced frequency. This dual-element approach allows extended, detailed highs without harshness. Sensitivity figures are not officially published.

N-10102 Crossover Network with Multi-Amplifier Support

The N-10102 crossover network handles the 800 Hz and 2.5 kHz transition points with a 6 dB/octave slope, a gentle roll-off that preserves phase coherence. The terminal section includes a multi-amplifier selector switch and corresponding terminals. This suggests Bozak anticipated bi-amping or even tri-amping, which was forward-thinking for the time. Owners report that crossover components, especially capacitors, can degrade over decades, so restoration is common. Upgrades to modern capacitors are frequently mentioned in restoration circles.

Historical Context

The B-302A is a refined iteration of the B-300, designed to fill a niche between compact monitors and full-range floorstanders. Documentation positions it as a "high-level medium-sized system," a label that reflects its balance of size, performance and price. The model could be assembled from earlier Bozak systems by adding the B-209B midrange driver and the N-10102 crossover, which suggests a modular design. This may have extended the life of earlier enclosures, since owners could upgrade without replacing the entire system.

Collectibility & Value

Market data is sparse, but one recorded auction lists a winning bid of $292.00 for a pair of B-302A speakers. Given the age and weight, surviving units often show wear or component fatigue. A known issue among owners is driver inhomogeneity, particularly in the woofers, when acquiring mismatched pairs. If both speakers lose bass simultaneously, the fault may lie upstream rather than in the drivers, suggesting a common mode problem in the signal chain. Restoration typically involves crossover work, with many enthusiasts replacing aging capacitors. Tilting the speakers rearward is another common modification, reportedly improving imaging and high-frequency dispersion.