This proprietary approach, called Phase Aligned, also creates
an off-axis null in the horizontal plane, putting more acoustical
energy on axis. Sure, the look of drivers firing out the side of
the box is different, but extensive listening tests backed by
measurement proved the design.
This proven LF method was again deployed in the NTL720. Like
the MF section, the LF woofers are 6-inch, with all four of these
drivers outfitted with powerful neodymium magnet structures
that also reduce weight.
While these drivers may seem a bit on the small side, the ability
of the Phase Aligned drivers to extend LF performance is
particularly advantageous in meeting the needs of applications
requiring a bit of added punch. In addition, the response of the
MF drivers is also extended down to 100 Hz, furthering low-end
presence and impact. (A low-pass filter on the LF drivers curtails
their output at about 300 Hz.) (Note the NTL720 crossover points
presented in
Figure 4
.)
THE GUNNESS FOCUSING™ DIFFERENCE
The onboard self-powering technology developed and proven
in the EAW NT Series, has been further extended for the NTL720.
It includes three individual modified 500-watt Class D (digital)
amplifier modules tailored for their respective subsections (LF,
LF/MF, and HF – all 4-ohm loads) and also precisely matched to
their own digital signal processors.
This reliable and very lightweight (9 lbs) amplification package
is easily field-replaceable (more on this later). It includes an
intelligent power supply control that affords optimum efficiency
with rock- solid immunity from AC line variations, with self-
resetting protection circuitry guarding against output overload,
overheating, power supply faults and excess output current.
Convection cooling eliminates the need for fans. (
Figure 5
)
Each DSP is tailored to best optimize its respective subsection,
providing response correction as well as EQ, delay, level, and
delay for additional tailoring and alignment control. Excursion
limiters add another layer of protection for the components.
Headlining the processing, however, is EAW’s revolutionary
Gunness Focusing™ alignment and driver processing algorithms
that deliver horn-loaded performance comparable to premium
direct-radiating studio monitors. Also first unveiled in the NT
Series, Gunness Focusing is now available – via the UX8800
digital processor – for an ever-increasing number of conventional
EAW loudspeakers, but it’s already onboard the NTL720.
To the point, Gunness Focusing eliminates the traditional
characteristics of “honk” and “splashiness” that can plague horn-
loaded loudspeaker designs. The honk of a horn is normally
heard in the lower frequencies of its band pass, while splashiness
(an attribute of compression drivers) is usually heard at the
highest frequencies and obscures the fine detail in instruments,
such as cymbals.
Likewise, cone drivers have inherent resonances in their upper
frequency range that result in “muddiness” in the middle of the
vocal range. These HF and LF behaviors combine to produce a
sonic signature commonly referred to as “coloration.”
DSP is the primary tool available for dealing with these types
of loudspeaker anomalies, with the EAW engineering team
recognizing that the key is understanding the trade-offs of
traditional DSP implementation. Therefore, the team first
developed a proprietary, software-based spectrograph for
acoustical analysis. This spectrograph, along with other analysis
tools, was used to investigate the unprocessed responses of HF
and LF subsystems in various directions and at various levels.
The analysis allowed various performance anomalies to be
isolated from each other. In this way, those anomalies that
were linear, time invariant, spatially consistent, and therefore
correctable, could be distinguished from anomalies without
those characteristics, and which were therefore not correctable.
The next step was to apply appropriate DSP to the correctable
anomalies.
Another analysis was performed on the standard, universally
used DSP algorithms. This test proved that these standard
algorithms simply did not produce filters with response shapes,
temporal behaviors, or resolutions with anywhere near the
required precisions or accuracies necessary to correct those
anomalies to which they were being applied. (
Figure 6
presents
before and after spectrographs of the dramatic impact made by
Gunness Focusing.)
Figure 4
Figure 5
