X-ONE
In addition, for geometric reasons a stacked cluster can provide
more extended vertical coverage than a flying one. For these rea-
sons, stacking makes sense in small configurations where only a few
elements can optimize audience coverage.
Flying is the best solution to achieve uniform sound pressure level
in case the number of elements arrayed is sufficient to provide, over
the entire audience, the necessary front-to-rear coverage. Flying is
also an excellent solution for sightline problems that commonly oc-
cur and provides better high frequency penetration into the audience
with reduced shadowing effects. For flying configurations, additional
speakers are added to cover center or front-fill requirements and to
help pull the localization image down towards the stage for the first
10-20 rows of the audience.
5. Stacking guidelines
The FOH engineer must know if the audience is standing or seated,
but, in any case, the bottom of the cluster should always be higher
than the heads of the audience in the first rows and the lowest ele-
ment tilted downwards. If the bottom of the cluster (consisting of
XTO speakers) is too low, the first rows could receive too high level
of SPL because audience members directly in front of the system act
as an acoustic screen for the rows behind them (shadowing).
Ideally, the MF-HF speakers should be positioned slightly above the
audience (in any case not lower than 2 m or 6.5 ft above floor level),
with a proper volume regulation as necessary.
Note: for extended bandwidth applications, a stack of 2 XTODS
double subwoofers - placed one on top of the other - provides a
stable stacking platform at a height of 1.05 m above ground level.
6. Subwoofers
Subwoofers are used to extend the frequency response of the XTO
system down to 30 Hz and to increase the overall SPL (without wors-
ening the potential audience hearing loss).
7. General Guidelines for the use of subwoofers
The number of subwoofers to be used depends on 3 parameters:
1) Number of XTO Elements. The standard number of XTOS sub-
woofers recommended is a 1:1 ratio and for XTODS subwoofers is
a 2:1 ratio (2 upper modules - 1 subwoofer).
2) Type of Program being reproduced. Standard subwoofer ratios
are recommended for classical music or corporate events. For these
applications, subwoofers act as a low frequency extension for XTO
and provide approximately 6 dB of low frequency contour. In this case,
the overall system will function as a 3-way extended bandwidth in bi-or
tri-amplification. For more demanding rock music applications, a ratio
of 1:2 (1 XTO - 2 XTOS) is recommended to provide a more suitable
low frequency contour (e.g. 2:4, 4:8, 8:16).
3) Type of Venue or Installation. The number of subwoofers is
standard when ground-stacked in open-air places.
8. Amplification
X-ONE loudspeaker systems are designed to be used with profes-
sional amplifiers able to produce the following outputs:
XTO: 800 W MF-HF (@ 8 Ohm)
XTOS: 1000 W LF (@ 8 Ohm)
XTODS: 2000 W LF (@ 4 Ohm)
Care should be taken to avoid amplifiers clipping. It is important to un-
derstand that a low power amplifier driven into clipping is more likely to
damage a loudspeaker than a higher power amplifier used within its rat-
ings. This is because music signals have a high peak-to-average “crest”
factor. When an amplifier is severally overdriven, its output waveform is
clipped (its peaks are squared off) - reducing the crest factor.
In extreme cases, the waveform can approach that of a square wave.
An amplifier is normally able to consume far more electric power un-
der these conditions than its undistorted rated power output.
The use of very high power amplifiers with output greater than those
recommended is discouraged.
Care should be taken to avoid switch-on surges, which can result in
momentary power peaks in excess of specified ratings. When pow-
ering up a sound system it is important to switch on the amplifiers
only after electric supply of the mixer and the control electronics have
stabilised. For the system powering down reverse the sequence by
switching off the power amplifiers first.
9. Connectors
The rear panel of XTO, XTOS and XTODS loudspeakers are fitted
with two Neutrik Speakon NL4 connectors.
All four pins of each connector are wired in parallel. The XTO uses
poles 2+/2- for mid-hi section in double amplification. The 1+/1-
poles are designed for woofer in bi-amp or for in full range system
with passive filter, for XTOS subwoofer and XTODS double sub-
woofers. Using the male connector as input, the female connector
allows a direct connection to additional speakers.
PINS 1+ 1- 2+ 2-
NL4
LF+
(XTO LF biamp)
(XTO full range)
LF-
(XTO LF biamp)
(XTO full range)
HF+
(XTO HF biamp)
HF-
(XTO HF biamp)
NL4 (XTOS)
(XTODS)
(XTOS)
(XTODS)
4 pins Speakon connector:
1+: Positive (+) woofer, XTO full range, XTOS, XTODS
1-: Negative (-) woofer, XTO full range, XTOS, XTODS
2+: Positive (+) high, XTO high
2-: Negative (-) high, XTO high
10. Cable lengths
When connecting loudspeakers to an amplifier, it is recommended that
the return resistance of the cable used is lower than one tenth of the
nominal impedance of the loudspeaker or systems in parallel.
The table below gives an indication of the maximum admissible cable
run for various cross-sectional conductors.
Maximum Cable Run
Conductor CSA 4 ohm 8 ohm
1.0 mm211 m 22 m
1.5 mm217 m 34 m
2.0 mm222 m 44 m
2.5 mm229 m 58 m
4.0 mm244 m 88 m
6.0 mm266 m 132 m
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