EAW KF750 Series, Touring Usage Manual

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The first chart (Fig. 3), showing array performance with no processing or equalization, predicts significant comb
filtering at most locations with the best summation at the far field. The next two charts (Figs. 4 and 5), show how
performance improves when the top row of KF750's is attenuated 9 dB and the next row down is attenuated 3 dB.
The final chart (Fig. 6), depicts final array performance when appropriate delay is added to the bottom row of
downfill KF755's. Note that overall output decreases only marginally while overall performance improves
dramatically.
Vertical Array Shading in the High Frequencies
The high frequency response at FOH is governed by both the KF755 and KF750 horn arrivals. For best performance,
the KF755 must be allowed to dominate. By simply shading the KF750 high frequency devices in the row above the
KF755’s, the build up of energy between 1kHz and 2kHz is eliminated as demonstrated in Figure 7 below. Note that
this response is generated by the same computer model referenced above.
By implementing these simple techniques, effective and extremely consistent array performance can be provided
using the simple dead hung array. These subtle adjustments are also achieved without a requirement for additional
processing. In fact, short of overall low frequency level adjustment, KF700 Series arrays can be utilized and
optimized by making minor adjustments to a few amplifier channels night in and night out in varying venues.
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
Array response without AS3D™
-40
-20
0
20
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
Now we add 9 dB attenuation on top row of KF750's...
-40
-20
0
20
AS3D™ array shading techniques and their effects
on the mid frequency response of a 4 over 1 KF700 Series array
-40
-20
0
20
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
...and finally we add appropriate delay
on the bottom row of downfill KF755's.
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
... plus 3 dB attenuation on second row of KF750's...
-40
-20
0
20
0 degrees -10 degrees -20 degrees
(in the vertical plane)
Figure 4 Figure 3
Figure 6 Figure 5