Field Coil Coaxial 15" Full Range Driver.
World first perfect synchronous coax in field-coil category, world heaviest full range unit!
Tens of years ago Maxonic was marketing the famed DS-405 driver. The DS701 inherited the basic technology to position mid and high range diaphragm from DS405; the diaphragm sits coaxially and in-phase, and was replaced the permanent type to field-coil type magnetic circuit.
Labors of Hercules have been achieved in the DS701.
Frequency response 25-20.000 hz, 104/db/W efficiency and forty, forty, FORTY (40) kilos weight... each!
... and P.S.U.
Cool!