Hybrid Audio Technologies Legatia SE - Manual (Page 18)

Legatia SE User’s Manual ©Hybrid Audio Technologies Page 18 of 73
Voice Coil
The voice coil diameter of the L3SE is a large 25.5mm (1-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.
Suspension
The inverted surround is butyl rubber which is highly consistent, and does not suffer the variance of
natural rubbers. This rubber surround terminates mechanical vibrations well, having a low stiffness
for positive damping of resonances. The spider material was chosen for optimal performance; the
spider is a 90/10 cotton/Nomex blend with single-dip low viscosity phenolic. This material provides
the stiffness desired without being overly brittle or stiff, where vibrations in the spider are well damped
and do not translate into the former or the cone.
Cone
Like other Legatia SE midrange designs, you will find no composite or metal cone materials used on
the L3SE, as our approach to point-sourcing is to allow the Legatia SE midbass/midrange driver to
effectively play into upper treble frequencies. The Legatia L3SE is a cone-type driver consisting of a
proprietary hybrid paper diaphragm with extremely low moving mass. Paper is widely acknowledged
as the best-damping material, as it provides the near optimum balance of strength and weight. The
cone has been treated with a water resistant element at the rear to accommodate door mounting, or
other areas prone to occasional contact with liquid. The cone design offers a wide dispersion pattern
to make for flexible installation and speaker location. The Legatia L3SE has an outstanding extended
frequency response; the usable frequency range of this driver exceeds seven complete octaves of
usable bandwidth on-axis (140 Hz – 18,000+ Hz). Even off-axis, the L3SE faithfully recreates more
than five full octaves of information, for the ultimate “small-format” midrange/full-range driver.
Phase Plug and Shorting Cup
The L3SE comes equipped with a phase plug pole piece extension at the center of the cone. The
phase plug is aluminum and, by design, ensures enhancement of the total inductance profile,
providing much of the inductance reduction benefits noted. The phase plug is plated with rose-tinted
copper, which by design does not negatively reduce eddy current, and adds thermal dissipation
potential, not to mention sleek, class-leading cosmetics. The phase plug extends well down inside
the pole vent, and acts as a very large and efficient heatsink for any heat that radiates into the pole.
The highest frequencies of audio emanate from the area around the center of the cone and the lower
frequencies are produced by the area of the cone that is farther from the center. The phase plug pole
piece extension improves the L3SE’s performance and clarity by deflecting delicate midrange and
treble tones forward of the driver, while minimizing distortion and improving bandwidth.
The L3SE uses a copper shorting cup. The shorting cup consist of an optimally sized and placed
copper (Cu) cup to create a total inductance profile that is not just low, but flat over stroke, frequency,
and power. Inductance is the number one limiter of high frequency extension and modulation of