(SECTION THREE: Anatomy of a Loudspeaker continued)
20
Cabinet Material
The LAT sides are constructed of extruded 6063-T5 aluminum. The rigid, dense
rear baffle made of 6061-T6 aluminum absorbs any vibration from the driver cones.
Using this heavy, inert metal means minimal vibrations—no matter how much power
the loudspeakers handle—and thus no loss of sound.
Crossover Design
Each group of driver units (tweeter, midrange, and woofer) on the LAT–1 and LAT–C
has its own dedicated crossover circuit board. Each circuit board is made of 1/8-inch
fiberglass and has a number of unique elements. To minimize parasitic inductance
and resistance, small capacitors are connected in parallel, and air-core inductors
are wound with oversize wire. In addition, each capacitor is placed in its own plastic
case, making it virtually immune to vibrations and pressure variations. This design
allows each drive unit to handle its portion of the music signal without strain, maxi-
mizes power delivery, and increases signal linearity while minimizing resistance and
inductance. High-current polypropylene film capacitors are used exclusively in the
audio signal path.
Similarly, the resistors in the crossover networks are connected in parallel to mini-
mize parasitic inductance and maximize current capacity and power dissipation.
Oversized, high-power, metal oxide and wirewound resistors are used exclusively.
All the inductors are air-core types; they suffer from none of the nonlinearities at low
signal levels and saturation at high signal levels that iron-core inductors exhibit. All
the inductors are wound with oversize wire, reducing parasitic resistance to a fraction
of an Ohm. In addition, the inductors in the midrange and tweeter filter networks are
wound with Litz wire for extended high-frequency linearity.
Drivers
LAT–1 drivers are custom-built to Krell specifications. The midrange cones have
five doped cuts, providing strength without the distortion that occurs when the entire
cone is doped. Woofer cones are reinforced with carbon fiber, which adds rigidity
and damps cone resonance. The dual concentric tweeter features an innovative
waveguide design that increases dispersion around its axis.
