d&b 24C - Manual (Page 8)

2.1.6. Aiming of the beam
The aiming of the beam of the HF array can be adjusted between
0° and –14°.
The DMAX/H scale on the left provides a simple means of
determining the correct setting for a given room geometry. The
assumption here is the listening plane is horizontal and the
loudspeaker column is mounted exactly vertically.
Simply take the maximum distance to be covered (DMAX) and
divide it by the height (H) above the listeners' ears up to the bottom
edge of the cabinet. Set the mark to the respective DMAX/H value.
Example:
A seated audience has a typical ear height of 1.20 m (4 ft)
above ground level. The bottom edge of the loudspeaker is at
2.70 m (9 ft) above ground level, i.e. 1.50 m (5 ft) above ear
level. The maximum distance to be covered is 18 m (60 ft).
The HF beam has therefore to be set to:
18 m / 1.50 m = 12 (60 ft / 5 ft =12)
To aim the beam, proceed as follows:
Tools required: 10 mm (1/4") wrench/spanner
1. At the rear, slacken the M6 hex head screw.
2. Slide the screw up or down to set the mark above the screw to
the calculated value.
3. Carefully retighten the screw.
HF beam set to DMAX/H = 12
d&b 24C/24C-E Manual 1.3 en 8