YL Acoustic D-1250

Commentary

Driver unit for bass developed as a full-scale pressure unit.

The diaphragm is molded with the same hard lightweight duralumin plate used for the middle sound.
This diaphragm is a lightweight diaphragm with a mass of about 4g.

The edge is made of a highly elastic plastic film that has been heated and corrugated. The plastic edge has almost no edge noise, and moreover, it is strong and there is no worry of losing. The resonance frequency ranges from 50 Hz to 70 Hz.
This edge realizes clear sound with little harmonic distortion.

The voice coil is made of copper ribbon wire with edgewise winding.

The magnet is a combination of cobalt steel and nickel with a weight of 7 kg.

The diameter of the throat is 75 mm.
There was a 75x75mm square throat 16-S sold separately for those making their own horn.

A horn with a cutoff frequency of approximately 20 Hz and a total length of 7 to 8m was recommended.
I recommended the material to be made of concrete, but when the horn was made of wood, it was set and deadened with cement to the place where it would sound.

Model Rating

Type	Low-range driver unit
Available bandwidth	16 Hz to 500 Hz
Impedance	8 Ω (16 Ω)
Maximum allowable input (peak value)	120W(100Hz) 30W(30Hz)
Magnetic flux density	14,000 gauss or more
Magnet	Cobalt steel, nickel
Magnet weight	7kg
Diaphragm diameter	125mm
External dimensions	Diameter 215x Height 180 mm
Weight	26kg