Front-Of-House (Foh) Applications; Stage Monitoring - L-Acoustics 112XT Operator's Manual

OFFSTAGE FILL
When the horizontal coverage of the main left/right FOH arrays is not sufficient to cover the entire
audience area, XT enclosures can also be used for offstage fill. Typically, throw distance requirements
are shorter and vertical coverage angles are greater, making XT a possible solution for this application.
Some Final Notes Concerning Fill Applications
Digital processor presets for 112XT and 115XT loudspeaker enclosures have been specifically engineered to
be sonically compatible with all other L-ACOUSTICS models.
FILL presets (nominally flat) are recommended for all proximity fill applications where the audience is
located close to fill loudspeakers – for example, front fill or stereo infill configurations.
Time alignment of complementary fill systems with the main left/right FOH arrays is necessary in order to
achieve optimum results. Placing your measurement microphone in a representative location where the fill
and main system coverage overlaps generally provides a good reference point for time alignment. WINMLS,
SMAART or SPECTRAFOO are cost-effective measurement tools that are recommended for this purpose.

4.6 FRONT-OF-HOUSE (FOH) APPLICATIONS

When 112XT or 115XT enclosures are used standalone (without subwoofers) for FOH applications,
there are two different types of 2-way preset available: 1) FRONT presets have 3 dB of low and high
frequency shelving equalization in order to provide a frequency response contour that is suitable for
music applications; 2) FILL presets have nominally flat response for use in speech reinforcement and
classical music applications or for when XT enclosures are used as a close proximity fill enclosure.
For 3-way operation of 112XT or 115XT loudspeaker enclosures with SB115, SB118, SB218 or dV-
SUB subwoofers there are two different types of preset available: 1) 3W presets optimize the power
bandwidth for the XT and its companion subwoofer due to the use of complimentary 100 Hz
crossover filtering and are recommended for all closely-coupled applications (for example, stacked
configurations); 2) 3WX presets can be employed when XT enclosures and subwoofers are physically
separated (for example, flown XT enclosures and ground stacked subwoofers).
For all FOH applications, please refer to Sections 4.2, 4.3, 4.4 concerning XT aiming, arraying and
coverage prediction. For additional information on using XT enclosures with subwoofers, please refer
to Section 4.8.

4.7 STAGE MONITORING

Given the power of digital signal processing and due to their compact, wedge-shaped format and axi-
symmetrical directivity, XT enclosures provide an extremely high performance, "plug and play" stage
monitoring solution.
FLOOR MONITORING
For floor monitoring applications, the coaxial component configuration employed in the 112XT and
115XT provides a high degree of image and coverage stability. The benefits of axi-symmetric
directivity are even more apparent since the performer is in close physical proximity to enclosure and
experiences a generous, homogeneous coverage pattern without the subjective impression (and
potential feedback problems) of listening to a separate horn / woofer combination.
MONITOR presets include additional low frequency equalization to account for half-space loading
conditions and are intended for either floor monitoring applications or fixed installations where the
XT is wall- or ceiling-mounted. In general, under half-space loading conditions, there is a 6 dB increase
around 100 Hz (due to floor coupling), followed by a broad cancellation that occurs between 200 –
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L-ACOUSTICS XT Manual V1.1 2/11/2003