Altec 403A (1968)
A 20 cm full-range speaker unit introduced in 1968, known for its high cost-performance while retaining Altec's signature tonal character.
Overview
The Altec 403A is a 20 cm cone type full-range speaker unit released in 1968 by Altec. It stands as a representative model among Altec's 20 cm full-range drivers, balancing performance and value. Multiple variations exist, reflecting changes in materials and construction over its production run. The unit was designed for use in high-fidelity audio systems where a single driver could cover most of the audible spectrum.
Specifications
| Type | 20 cm cone type full range speaker |
| Frequency characteristic | 70 Hz to 11 kHz |
| Lowest resonance frequency | 80Hz |
| Impedance | 8 Ω |
| Rated input | 12W |
| Output sound pressure level | 102dB/W/m |
| Magnetic flux density | 9,000gauss |
| External dimensions | Diameter 211x Depth 102 mm |
| Weight | 1.35 kg (1970 catalog) / 1.4 kg (1976 catalog) |
Design
The 403A was initially built with an Alnico magnet and features a frame with a slit-shaped back. Around 1970, the frame slit design was modified. Later versions transitioned to a ferrite magnetic circuit. In early ferrite models, the magnetic circuit was painted and bore a model label on top; this was later changed to an unpainted circuit with a revised label. The cone's corn paper also evolved, with corrugation added in later production batches. Several variations of the 403A exist, reflecting these incremental design updates.
Reception
While inheriting the tonal character typical of Altec speakers, the 403A delivered high cost-performance, making it a practical choice for audiophiles and system builders seeking Altec sound without the premium of more exotic models.
Market
Original pricing for the 403A was ¥6,500 per unit around 1970, increased to ¥7,400 following a price revision, and listed at ¥6,700 around 1976.
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