X-Treme Audio Classic Line - Manual (Page 4)

CLASSIC LINE
Fig. 6 Cross section of the long throw module XTLT
The XTLT is an extremely efficient 2 way system with a horn mid-
range with three 6” drivers and a tweeter with two 1” throat diam-
eter compression drivers. The system is a mid-high frequency long
throw module, designed to produce a planar wave front from an
8”x1” rectangular throat. It employs a pair of compression drivers
and three mid-range speakers; the special dual wave guide con-
tains a shared vertical slot able to radiate a coherent planar wave
front. It can be used as long throw module for traditional “Classic
Line” clusters. The main advantage of these types of system is the
energy savings arising from the narrowing of the vertical directivity
and having highly directive sources that, in addition, generate sound
waves that attenuate by only 3 dB for every doubling of distance as
opposed to 6 dB for conventional systems. The XTLT neodymium
drivers are mounted on a special aluminium heat sink for increased
power handling and reduced power compression. While the planar
wave driver is a distinctive new transducer engineered to radiate a
coherent planar wave front from a rectangular piston without inter-
nal diffraction, the XTLT horn loading system uses more conven-
tional wave guide design techniques to reshape the compression
driver’s spherical wave front into planar wave front.
3. Instructions
The “Classic” configuration consists of the XTH, XTL, XTS and XTLT
speakers which can be set directly on the floor as well as suspend-
ed. The back angle of the cabinets allows the correct arrangement
of the speakers, so that the nominal scattering values in the horizon-
tal plane are respected. A homogenous horizontal covering without
any phase interference is made possible by the application of the
configuration formed by two XTH and XTL systems. Floor stacks
are generally made by placing the loudspeaker systems directly
one on top of the other. Specifically, as there is no vertical angula-
tion among the different XTH speakers in a stacked configuration,
a coupling effect on the medium-high frequencies is obtained, in-
creasing the vertical directivity and allowing the achievement of an
extraordinary coverage, even at a long distance.
Classic Line clusters can be created by placing different XTH speak-
ers side by side, with angles between twenty and thirty degree on
the horizontal plane.
In case of angles of lower degree between cabinets, you will get a
lower horizontal coverage and a higher acoustic pressure level in the
central axis of the cluster.
In any case the horizontal plane coverage should not exceed the
listening area in order not to send out emissions to areas that might
create undesired sound reverberation and interference or that may
lie outside the musical event.
The positioning of a vertical cluster of loudspeaker systems de-
pends on both the height of the system from the floor as well as
the required coverage area. We generally recommend you employ
an angle of five degree between two adjacent module cabinets in a
suspended cluster.
Fig. 7 Clusters for a 180° horizontal coverage
4. Stacking or flying?
Although suspended systems are generally preferred by most
sound engineers, there are good arguments to support both solu-
tions. In many cases the answer is dictated by logistics that are
venue-specific, i.e. sometimes it is not possible to hang the PA.
Stacking on stage lowers the perceived sound image to stage level
which is beneficial in small venues. Stacking also offers more low
frequency SPL due to enhanced floor coupling and, since XTH has
less SPL attenuation from the front to the back of the audience than
traditional systems, this allows a stacked system to project further.
In addition, for geometric reasons a stacked array can provide more
extended vertical coverage than a flying one. For these reasons,
stacking makes sense in small configurations where only a few ele-
ments can optimize audience coverage.
Flying systems are the best solution to achieve uniform sound pres-
sure level and even tonal balance over the entire audience only if
the number of elements arrayed is sufficient to provide the neces-
sary front to rear coverage. Flying is also an excellent solution for
sightline problems - that commonly occur - and provides better high
frequency penetration into the audience with reduced shadowing ef-
fects. For hung configurations, additional speakers are added to cov-
er center or front-fill requirements and to help pull the localization im-
age down towards the stage for the first 10-20 rows of the audience.
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