AKAI ST-400

Commentary

The top speaker system of the ST series.

The ST Series has an acoustic filter in the low-frequency unit.
This acoustic filter works to cut out medium - and high-frequency distortion that cannot be removed only by the electrical network on the input side, thereby cutting out signals and distortion outside the network band that are output as sound on the output side.
In addition, by developing a unique acoustic filter that can obtain the same characteristics as a large loss without using a loss material that causes damping noise, distortion that could not be removed in the past has been removed.

The low-range is equipped with a 30 cm cone woofer with an acoustic filter on the front.
This unit uses a special edge to reduce the minimum resonant frequency by calculating a balance with the mass of the edge.

A 3.8 cm dome type tweeter is installed in the middle range and a 3.1 cm dome type tweeter is installed in the high range.
In the ST Series, the diaphragm is not made larger than necessary, and the unit size is adopted in consideration of the balance with directivity. By this, the voice coil diameter is larger than the area of the diaphragm, enabling stable piston vibration.

It is equipped with a variable level control that can adjust the middle and high ranges separately.

We have adopted a closed-type enclosure that uses both homogen and lauan materials.
The plate thickness is 21 mm in consideration of the balance with the unit. The exterior features a walnut oil finish.

Model Rating

Method	3-Way, 3-Speaker, Airtight Type, Bookshelf Type
Units Used	For low band : 30 cm cone type For Middle Area : 3.8 cm Dome Type For high-pass : 3.1 cm dome type
Frequency characteristic	20 Hz to 20 kHz
Max Input	50W
Impedance	8 Ω
Crossover frequency	700 Hz, 5 kHz
Network	12dB/oct., 6dB/oct.
External dimensions	Width 360x Height 780x Depth 300 mm
Weight	21.5kg