d&b 16C - Manual (Page 5)

2.1. Product description
The 16C is a passive 2-way column loudspeaker housing four 4”
neodymium drivers and a 0.75” compression driver mounted on a
CD horn.
In the vertical plane, the cabinet provides directivity control down
to 500 Hz.
The HF horn has a nominal dispersion of 90° x 40° (h x v).
The 4" drivers are arranged in a unique cardioid setup radiating
through waveguide elements at the front and damped ports at the
rear of the cabinet. This design provides a cardioid dispersion
pattern with an average broadband attenuation to the rear of
approx. 18 dB.
The loudspeaker cabinets are based on an extruded aluminum
profile with a metal grill protecting the front of the loudspeaker.
Two continuous rails (8 mm, T-slot profiles) are provided at the rear
for attaching a wall mount bracket.
2.1.1. Cardioid dispersion
Due to their dimensions, conventional column loudspeakers
provide no significant horizontal directivity below 2 kHz.
At low and mid frequencies, the resulting polar pattern is almost
omni-directional (dotted line).
The cardioid patterns of the 16C show a much higher directivity
resulting in much less energy radiated into the room (continuous
line).
Typically, column loudspeakers are mounted onto walls or other
hard plane surfaces. Hard surfaces act as an acoustic mirror. That
means, the room is not only covered by the sound of the actual
column loudspeaker but also by the sound produced by its virtual
mirror source from "behind".
In the case of conventional column loudspeakers with their low
horizontal directivity, the mirror source radiates at a similar level as
the loudspeaker itself.
The combination of both sources results in a dipolar characteristic
where the main energy is radiated along the walls (dotted line).
The 16C, however, with its cardioid dispersion pattern provides an
even dispersion characteristic and a useful directivity when
mounted onto a wall.
2.1.1.1. Flush mounting
If architecturally required, xC-Series cabinets may be partially flush
mounted.
Please note that this will render the cardioid ports ineffective and
as a result, may change the dispersion pattern.
2. 16C loudspeaker
d&b 16C Manual 1.2 en 5