5-2
A1 User Manual
stances (the distances between the sources in the array are so small
that any combing effect would only occur at relatively high fre-
quencies) than with how closely defined and controlled the driver
dispersion patterns are. Once more, the design of the active sy-
stems cabinets, in particular the use of CD horns, largely eliminates
these problems and simplifies the creation of effective loudspeaker
arrays - placing F1220 cabinets with their rear side panels butted
together guarantees minimal dispersion pattern overlap and hence
minimal interference.
A final configuration trick, particularly useful in deep rooms where
more than one cabinet has to be used because a single cabinet has
insufficient throw for the level needed at the back of the room, is
to vertically stack the cabinets rather than horizontally array them
- this helps minimise audible interference and gives more vertical
directivity.
5.1.3. Stacking subwoofers
Regardless of the type and operating principles of the subwoofer
systems, the basic relationships of coverage and array directivity at
bass frequencies apply.
−
Vertical subwoofer arrays have better bass throw. The increa-
sed vertical directivity of such arrays dissipates less energy in
the vertical plane.
−
Wide subwoofer arrays, with their greater horizontal directivity,
are more effective when trying to achieve a more even level
distribution in the horizontal plane, e.g. between the centre and
sides of a coverage area. The typical bass emphasis on the
central axis between two front stacks can be reduced by out-
wardly rotating the two subwoofer arrays - the broader the ar-
ray, the more even the coverage.
If a large number of subwoofers are available, then an L-shape
configuration can combine the best properties of the two variants.
The arrangement of subwoofers in flying arrays (F2/B1/C4 sy-
stems) is often determined by the position of the TOP cabinets, i.e.
the coverage requirements of the array. However, it is important
to ensure that the subwoofer systems are also arranged in groups
(blocks, rows or columns) in order to benefit from the coupling ef-
fects described above.
