V1.22
Owners Manual SP20-Linex™
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Basic configuration principles
With respect to the horizontal coverage a line-array should not differ from a conventional
constant directivity (CD)-system. When more horizontal coverage is needed than the horizontal
dispersion of one line-array some basic rules apply explained later in this chapter. The main
variable to which a line-array can- and has to be adapted is the vertical coverage.
Establishing proper vertical coverage
The first step in the configuration process is to get the venue parameters and listeners positions
right. It may seem logical but a good preparation is the main time-saver in setting up any audio-
system. Once these parameters, such as distances to first and last listener positions and flying
height, are known prediction software such as SPArC™ can easily be employed to configure the
best array shape and size.
When a line array is flown it is most logical to configure from top to bottom (far coverage to
near coverage). Therefore it might not always be possible to point the bottom array element to
the nearest listener position to be fed by the line-array (e.g. due to limited number of array
elements). Additional front fill is then necessary. Another situation where front fill is preferred is
when the array is flying relatively high to the first listeners position. In order to avoid 'elevator-
music' coming from above, front fills placed at stage height will place the sound image
downward for the front of the audience.
When a line array is ground stacked it is more logic to configure the array from bottom to top.
Additional front fill can still be used, however often not necessary.
The requested SPL and venue shape (e.g. arena type or flat field) largely determine the angle
settings within the array. If the variation in audience distance is large (e.g. flat floor) minimal “j-
shaping” of the array may be needed to achieve a more even loudness throughout the field and
to compensate for the losses due to air attenuation. This however increases the number of array
elements needed for a certain vertical coverage angle. If the variation in distance from array to
the audience is small (e.g. the distance between the shortest and the longest distance to the
audience is not more than doubled), a constant angle setting between the elements is
recommended. This will often be the case in small theatres, amphi-theatres or sports arenas.
Constant angle settings between the elements are also recommended whenever the array is very
short (1.2m and below), since a lot of the lower frequency band will have a wide vertical
dispersion in such an array.
The angle increments between array elements shall always be as smooth as possible to not
disrupt the coherent wave front emitted by the array. It is advised to use only constant or
increasing angles from top to bottom when flown or stacked. Furthermore it is advised to use
only the zero angle setting when (very) long throw (40 meters or more) situations apply and/or
large arrays are used (12 elements or more).
Be generous when deciding a certain vertical coverage angle, otherwise (large)
amounts of listeners might be partially in the – 6dB coverage area. This means they will
hear less low-mid frequencies! This effect is most pronounced at large distances. In
general one to three cabinets extra coverage for the furthest audience will be sufficient.
