Spiral or Progressive Array - Unlike a J-Array, spiral or progressive
array is a continuous curve. The upper portion of the array is nearly
straight but then increases in curvature towards the bottom. Most small
and mid-sized venues get covered very well with this type of array
formation and we recommend this formation when installing four to
eight SLA 40T. This would be the situation with majority of the installers
of SLA 40T. With this configuration one can expect very uniform
coverage over the entire audience area. In a spiral array the angle
between successive enclosures changes by a predetermined incremental
angle. SLA-40T has provision for 0°-2°-4°-6°-8°-10° tilt angles.
J-Array – This is a combination of straight and curved arrays. In the
real world Line Arrays are almost always used as curved vertical arrays.
A large venue may consist of a dozen enclosures, with top two to four
enclosures straight with 0° vertical splay, aimed at the farthest seats.
As we move down the array, the angle between adjacent enclosures
increases until at the bottom there are one or two modules aimed
almost straight down to cover the front seating area. Therefore a
J-Array has upper portion of the array as straight and then increases
in curvature toward the bottom giving the array the shape of letter J.
Therefore the incremental angle of 2° will yield 0°, 2°, 6°, 12°, 20°, 30°,40°, 50° aiming angles relative to the
horizontal when eight SLA 40T enclosures are flown. The topmost module has 0° tilt and lowest (eighth) has 50° tilt
relative to horizontal.
Powering of topmost enclosure is at full power and subsequent ones are progressively turned down a little. This way
a reasonably even coverage with almost equal SPL in the front seating area and farthest seating area is achievable.
SLA40T has a switch for providing HF attenuation of -3dB,-6dB, & -9dB. This feature can be utilized during
equalization of the frequency response. A reasonably even frequency response in the entire listening area is also
aided by the wave-guide loaded HF drivers of SLA 40T.
-9dB
-6dB
-3dB
-0dB
Sensitivity Settings: The sensitivity knob is located on rear panel of the
SLA 40T. This is used to adjust the HF attenuation of the SLA 40T module.
A flat screwdriver can be used to change settings as required.
Splay / Tilt Angle: This set of angled grooves can be used to tilt the
modules in perspective to the other stacked modules, in order to form the
numerous flying configurations.
10°
8°
6°
4°
2°
0°
5