About Your Loudspeaker 21/01/03 11:06 am Page 3
COINCIDENT DRIVER ALIGNMENT
970mm
3000mm
THE DRIVE UNITS
THE 380mm 15” BASS DRIVER
The bass driver incorporates a new design of cone, it is a sandwich cone combination of glass fibre/carbon fibre/glass fibre, it is very stiff and rigid. Energy losses in the cone transfer mechanism will be low. The cone edge is rim stiffened also.
Similarly, the lateral voice coil strength is very high being a combination of half hard aluminium and resin bond- ed to glass fibre. The dust cap/cover is of the same material as the cone. As the 15” operates only over the LF range it is only used over its pistonic range. The cone surround is a large half roll of synthetic butyl rubber, it has good inherent damping quality and has an integral trim ring. The chassis used and indeed on the 8” midrange also, is an open design, where narrow ‘legs’ and largest openings are used to minimise back reflections.
A dual spider configuration is used to extend the stable performance life of the driver and mechanical damping. A high performance traditional alnico magnet system is used. This features a flux stabilisation ring at the base of the yoke assembly. The magnet system is also fully vented throughout.
A real problem with high output bass systems is motional noise from the speakers particularly the bass driver. Careful assessment has eliminated pressure ‘air noise’ there are vents in the cone, in the spider, in the coil, in the magnet system, and in the chassis.
THE 200mm 8” UPPER BASS TO MID-RANGE DRIVER
The driver utilises a lightweight kevlar cone, a very rigid and responsive cone choice. A solid composition dust dome is used. The voice coil is wound on a vented aluminium former, and is also very rigid. The cone is terminated with a conventional half roll SBR surround with integral. A high performance alnico magnet is used. This also features a flux stabilisation ring at the base of the yoke assembly. The magnet system is also vented through.
