These very rare 1971 National SB-400 speakers are in amazing condition, these where also branded under the Technics banner in Japan. National was a brand used by Panasonic Corporation (formerly Matsushita Electric Industrial Co., Ltd.). After 1980 in Europe, and after 1988 in Australia and New Zealand, Matsushita ceased the usage of “National”, and sold audiovisual products exclusively under the Panasonic and Technics nameplates. Description Speaker system with the theme of multi-cell horn, worked to improve the transient response and directional characteristics. 25cm cone type Woofer high compliance type in low-pass. Improved linearity and power handling by molding the shape of the convex and concave reverse edge. Horn type squawker for the mid range. Horn is a multi-cell horn 8-cell type, by dividing the cell in vertical and horizontal horn inside, with an improved directivity, which is a problem with horn types. It employs a hard duralumin diaphragm, and has improvement for transient performance and low distortion. Horn type tweeter using the multi-cell horn 6-cell configuration. It is equipped with an attenuator independent in high and mid-range, switching can be in three stages. Sealed speaker enclosure, teak veneer is oil finished. Multi-amplifier terminals, mode selection switch, can be controlled by multiple amplifiers 2-way / 3-way. Specifications 3 way, 3 speakers, sealed cabinet, bookshelf type system Low-pass woofer: 25cm cone type Mid-range: Horn type Tweeter: Horn type Frequency response: 35Hz ~ 20,000Hz Impedance: 8Ω Output sound pressure level: 93dB/W/m Allowable input: 38W Crossover frequency: 650Hz, 6,000Hz Level control in regions: +3 ~ 0 ~-3dB (OFF switch installed) For high regions: +3 ~ 0 ~-3dB (OFF switch installed) H590 mm × W316 mm × D300 mm Weight: 12kg each