d&b TI 385 d&b Line array design - Manual (Page 14)

8. The d&b point sources
From Version V7x.x, a range of d&b point source
loudspeakers is available for integration into a project. All
current top cabinets of the E-Series, Y(i)P-Series, Q(i)7,
Q(i)10, T(i)10PS and xS-Series can be selected, both in
stand-alone projects and in combination with line arrays.
Please note that a T(i)10L loudspeaker that is deployed
horizontally may also be used as a single nearfill with the
T10PS setup although its polar dispersion does not reflect a
"point source".
For cabinets that are equipped with rotatable HF horns,
both horn orientations can be selected separately. Each
selectable orientation for a specific loudspeaker type uses
its own measured polar data set. This is defined by the
chosen nominal horizontal and vertical dispersion angles
and follows the convention [SystemName] [horizontal
dispersion] x [vertical dispersion] while the cabinet itself
remains in its typical mechanical orientation, i.e. in an
upright position (e.g. 10S 75x50; E6 55x100; Q7 40x75
etc).
If a system is used lying on its side, the standard dataset
must be used and the cabinet rotation must be set to either
90°(on its left side, seen from a listener's position) or 270°
(on its right side, seen from a listener's position). The cabinet
can be rotated in steps of 90° degrees. Each individual
cabinet can be freely positioned within the room with
horizontal or vertical aiming.
Selecting a loudspeaker optionally displays a balloon polar
plot or its vertical aiming into the room.
More specific loudspeaker data can be found in the
relevant documentation of the respective d&b products.
8.1 Number of cabinets required
The number of point source cabinets is primarily defined by
their specific application, for example as nearfill or delay
systems or as the main system. Of course, the number of
cabinets also depends on the desired level, the distances to
be covered and the directivity requirements in the particular
venue or project. Using the d&b ArrayCalc calculator will
prove whether the system is able to fulfill the specific
requirements.
Depending on the program material and the desired level,
additional d&b subwoofer systems may be necessary to
extend the bandwidth and headroom
When used with subwoofers, the point sources should be
operated in CUT mode to gain maximum headroom at low
frequencies.
9. Column loudspeakers
The xC-Series column loudspeakers are passive 2-way
designs with a passive bandpass system providing a
cardioid dispersion control with an 18 dB average
broadband attenuation to the rear of the loudspeakers.
The 16C behaves as a standard point source cabinet with
a 90° x 40° (h x v) dispersion and is treated accordingly
in ArrayCalc. Its HF horn orientation is fixed, as a result
there is one single set of data available. You can, of course,
change the orientation of the cabinet itself like with all point
sources.
The 24C provides a special 90° x 20° pattern with a
variable vertical aiming to produce an even level
distribution over a typical audience area. This is achieved
by adjusting the vertical angle of the complete HF array
between 0° and –14°combined with a 5° down tilt to the
dispersion of low and mid frequencies.
When the 24C-E Cardioid column extender is attached,
vertical dispersion control is extended towards low
frequencies by another full octave.
TI 385 (6.0 EN) d&b Line array design, ArrayCalc V8.x Page 14 of 54