Hybrid Audio Technologies Legatia Pro - Manual (Page 14)

Legatia Pro User’s Manual ©Hybrid Audio Technologies Page 14 of 43
tuned chamber, discussed below, to allow for mounting of the L3 Pro in a simple baffle without worry
of separating front and back waves, nor building an enclosure. The rear of the body propagates
diaphragm back pressure into the tuned chamber to provide adequate communication to the back of
the dome for acoustic suspension and proper operation.
Housing and Tuned Chamber
In addition to the aluminum body of the Pro-series drivers, the L3 Pro includes a cast polypropylene
tuned and damped chamber at the rear of the motor assembly; the damped chamber helps to reduce
backwave distortion and significantly lower the Pro-series driver’s resonance frequency to allow it to
be used to play tones near its resonance frequency. The chamber for the L3 Pro is approximately 20
cm
3
in internal volume. A machined aluminum knurled attachment nut at the base of the L3 Pro
provides optimized clamping strength to the mounting media, and important feature for terminating
modal distortion at the mounting baffle.
Motor
The motor of the L3 Pro is paramount to the performance of the driver, providing for a flat and wide
BL curve (as a learning note, BL is the equivalent of torque in a car; a car with a flat and constant
torque curve provides much better acceleration and performance than a car with a peaky, non-
constant torque curve). The BL curve is flat and extended, yielding 4mm of two-way linear excursion,
resulting in the L3 Pro being able to accurately track the input signal. Reduced distortion and greater
dynamics are the immediate sonic benefits. The motor of the L3 Pro includes an NdFeB magnet to
improve restorative force, compliance, motor strength, displacement, and power handling. The
magnet assembly fully surrounds the voice coil.
Voice Coil
The voice coil diameter of the L3 Pro is a large 50.5mm (2-inch), which is the proper balance between
size and moving mass in super high-end mobile audio midranges/full-range drivers. The voice coil
diameter serves several key functions: elevated power handling, dissipation of heat (thereby lowering
power compression), and maximizing the size of the magnet assembly for enhanced motor
compliance. The voice coil is high-purity aluminum, which is superior to copper for heat dissipation,
as well as significantly reduced moving mass. The result is an extremely light weight winding with
good power handling and low inductance.
Dome
You will find no composite or metal cone materials used on the L3 Pro, as our approach to point-
sourcing is to allow the Legatia Pro midrange driver to effectively play into upper treble frequencies.
The Legatia L3 Pro is a dome-type driver consisting of a proprietary Japanese fine cotton hybrid
diaphragm with extremely low moving mass. Cotton is widely acknowledged as the best-damping
material for dome midrange drivers, as it provides the near optimum balance of strength and weight.
The dome has been treated with a water resistant element to accommodate door mounting, or other
areas prone to occasional contact with liquid. The dome design offers an exceptional dispersion
pattern to make for flexible installation and speaker location. The Legatia L3 Pro has an outstanding
extended frequency response; the usable frequency range of this driver exceeds seven complete
octaves of usable bandwidth on-axis (250 Hz – 13,000+ Hz). Even off-axis, the L3 Pro faithfully