Spotlight on the Radian 475PB 1-Inch Compression Driver
In January 2019, Vance Dickason characterized the 475PB 1" compression driver from Radian Audio Engineering. This was the second ferrite motor compression driver from Radian to be featured in Test Bench, following the 745PB, covered in the December 2018 issue. The Radian 475PB has a similar set of features as Radian’s 745PB and includes a 1” throat diameter, a 134 mm × 19 mm ferrite magnet motor, a high-temperature 44.5 mm (1.7”) diameter polyimide voice coil former wound with copper-clad aluminum edge-wound ribbon wire voice coil, 50 W AES power handling above 800 Hz and 100 W program power handing.
Radian diaphragm assemblies are self-aligning and may be rapidly serviced in the field by simply removing the three screws on the driver’s backcap and carefully replacing the old unit with the new one. The 475PB also features a copper shorting ring located in the gap area, and the most important feature — a proprietary processed and hardened aerospace-grade aluminum alloy diaphragm over a three-slit phase plug.
For this edition of Vance Dickason's Testench (available here
) the Radian 475PB compression driver was measured using an Eminence H 290B 90×40 ABS exponential horn, recommended by Radian.
The Radian 450PB, 465PB and the 475PB, with a 1.75” diaphragm, represent the refinement of our design efforts in 1” exit-format compression driver technology. See all the available options and specs here