Hybrid Audio Technologies Legatia - Manual (Page 7)

Legatia User’s Manual ©Hybrid Audio Technologies Page 7 of 65
performance and clarity of all Legatia midrange and midbass designs by deflecting delicate midrange
and treble tones forward of the driver, while minimizing distortion and improving bandwidth.
All Legatia midrange and midbass drivers use copper shorting rings. The shorting rings consist of
optimally sized and placed rings of copper (Cu) 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 inductance with stroke, frequency and power, and is the primary source
of intermodulation distortion (IMD).
Cone
The shape, weight and strength of the Legatia midrange and midbass cones relate directly to the
extended frequency response of the Legatia range of drivers (in concert with the extended phase plug
pole piece, noted above). The Legatia cones are concave-shaped hybrid paper diaphragms,
described below. Convex shaped cones, typical of “dome” midranges, typically exhibit “peaky”
frequency response, so we opted instead on a concave cone topology for the resultant smoother
frequency response. And contrary to common belief, most convex cones have a narrow directivity
pattern. The concave cone of the Legatia midrange and midbass drivers have a wider directivity
pattern, and are excellent for use in “off-axis” applications.
You will find no composite or metal cone materials used in any Legatia midrange or midbass driver.
Our approach to point-sourcing is to allow the Legatia midbass/midrange drivers to effectively play
into treble frequencies; having virtually all imaging cues emanating from one set of drivers in an
installation ensures stable stereo imaging across the fundamental frequencies which define image
placement and definition. The Legatia midrange and midbass drivers include 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 paper cone is
critical to tame unwanted cone modes, resonances, and the classic “cone breakup” associated with
most composite cones, but still be rigid enough for upper midbass response. All cones have been
treated with a water resistant element at the rear to accommodate door mounting, or other areas
prone to occasional contact with liquid.
All Legatia designs offer an outstanding extended frequency response; the usable frequency range of
the Legatia midrange and midbass drivers is at least six full octaves, and in many cases, seven or
more octaves of usable bandwidth with proper installation, aiming, set-up, and tuning. And because
of the employed cone technology which boasts exceptional off-axis response, described above, all
Legatia drivers offer exceptional off-axis bandwidth as well, exceeding five octaves for all designs.
Suspension
All Legatia midrange and midbass drivers include an inverted surround made of 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
surround, which acts as an air seal between the cone and the basket, adds to the restoring force of
the spider. Another function of the surround is to absorb cone flexure waves as they are transferred
up the cone. You'll also know a Legatia midrange and midbass design by its inverted surround; this
design feature allows for the use of a smaller height grille, and more flexibility in mounting options.
The spider material was chosen for optimal performance in all models; the spider is a 90/10
cotton/Nomex blend with single-dip low viscosity phenolic. This material provides the stiffness