5. AIMING
The maximum possible on-axis sound pressure level is achieved through the simple stacking or flying in a
straight line of from 2 to 4 COBRA TOPs. Since, however, doubling the number of tops halves the vertical
dispersion angle, when setting up using up to the maximum of 4 tops, particular attention must be paid to the
way the entire stack is aimed.
Angle of dispersion
NOTE: 1 x COBRA TOP: horizontal 120° vertical 30°
2 x COBRA TOPs stacked vertically horizontal 120° vertical 15°
4 x COBRA TOPs stacked vertically horizontal 120° vertical 7.5°
The following illustrations show the directivity of a stack of four COBRA TOPs in relation to a FOH position
at a distance of 20 metres with various arrangements of the speakers.
Figure 07
With a straight or stacked arrangement at a height of around 3 to 4 metres the main axis of radiation passes
over the head of the listener
(see fig.07)
.
Figure 08
If we now incline the entire stack of 4 enclosures 2 – 3° downwards there is a gain of around + 6 dB in sound
pressure levels at the FOH position.
(see fig. 08)
The measurements have been done with a line array from omnidirectional point sources with isophase
characteristics.
To Next Page
Loading...
