ALTEC LANSING 403A

Commentary

This is a 20 cm cone type full range speaker unit which is said to be a representative model among Altec's 20 cm full range speakers.

While inheriting the tone character of Altec, it realizes high cost performance.

There were several variations of the 403A.
Alnico magnet was used in the initial stage, and the back side of the frame is slit-shaped. It seems that the slit of the frame was changed around 70 years. After that, the magnetic circuit is changed to ferrite. In the ferrite model, the magnetic circuit was also painted in the initial stage and the label of the model name was put on top of it. After that, the label was changed and the magnetic circuit was not painted after years.
In addition, the corn paper was also changed from the middle, and it seems that the corrugation was installed in the latter period.

Model Rating

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	1.4 kg (according to 1976 catalog) 1.35 kg (according to 1970 catalog)