Came across these the other day.
Diatone is an OEM speaker manufacturer owned by Mitsubishi. They produced some very interesting and quite high end designs. Many of which never left the shores of Japan.
Gallery
First is the Diatone D-80
System 1 way, 1 speaker bass-reflex system, and a floor type
Use unit For low-pass: 80cm corn type
Rated impedance 4ohms
Play frequency band 15Hz - 500Hz
Antiresonance frequency 23Hz
Output sound pressure level 100dB/W/m
The maximum input 1000W(EIAJ)
Dimensions Width 1000x height 1350x depth of 667mm
Weight 150kg
These were also available in a domestic cabinet.
However, these were rather insignificant compared to what followed.
The Diatone D-160
So called due to its 160cm (63") diameter cone.
System 1 way, 1 speaker bass-reflex system
160cm honeycomb corn type (PW-1600)
Low-pass play limit 8Hz
The maximum input 3000W
The 3300 pound D-160 measures 7.8 x 7.6 x 4.5 feet.
There is a pair of the D-80s in the London nightclub The Fridge. It is quite apt, as the cabinets are easily the size of most domestic fridge freezers. What they lack in subtlety, they more than make up with extreme presence.