RCF HDL10-A 1400W Dual 8" Active Line Array Module (Black) - Manual (Page 19)

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ENGLISH
Once the design (number of elements and vertical splay angles) has been designed using
Shape Designer software, you can effectively optimise the array depending on the environment
and the application by driving it using different DSP presets stored onboard. Typically arrays
are divided in two or three zones depending the design and size of the array.
To optimise and EQ the array, different strategies are used for high frequencies (long throws
and short throws) and low frequencies.
The longer the distance, the greater the attenuation at high frequencies. Generally, high
frequencies need a correction to compensate for energy lost over distance; the correction
needed is usually proportional to the distance and high-frequency air absorption. In the
near- to mid-field, the air absorption is not nearly as critical; in this zone, high frequencies
need little additional correction.
In the next figure is shown the equalization that corresponds to HF settings for NEAR and
FAR:
HIGH-FREQUENCY
EQUALIZATION STRATEGIES
OPTIMIZING
THE ARRAY
While wave-guides provide isolated control over various mid- to high-frequency coverage areas,
the low-frequency section of a HDL array still requires mutual coupling - with equal amplitude
and phase - to achieve better directionality. Low-frequency directionality is less dependent on the
array’s relative splay angles and more dependent on the number of elements of the array.
At low frequencies, the more elements in the array (the longer the array), the more directional the
array becomes, providing more SPL in this range. The directional control of the array is achieved
when the length of the array is similar or larger than the wavelength of the frequencies being
reproduced by the array.
Although the array can (and usually should) be zoned for implementing different
equalization curves for high frequencies, identical equalization should be maintained in all
the low-frequency filters.
Different low-frequency equalization settings in the same array will degrade the desired
coupling effect. For the same reason, gain differences are not recommended for line arrays,
since adjusting various zones with an overall amplitude control for each results in decrease
of Low-frequency headroom and directionality.
In any case, line arrays generally need a correction to compensate for energy sum on lows.
In the next figure is shown the equalization that corresponds to CLUSTER settings, referring
to different number of speakers from 2-3 up to 10-16.
Increasing the number of cabinets,
response curves are decreased in order to compensate the low-frequency section mutual
coupling.
LOW-FREQUENCY COUPLING
EFFECTS
LOW-FREQUENCY STRATEGIES