Flown Dv-Dosc, Ground Stacked Sb Subwoofers (3-Way System Operation); Figure 63: Flown Dv-Dosc And Ground Stacked Sb218 3-Way System Configurations; Figure 64: Flown Dv-Dosc And Ground Stacked Subwoofer Time Alignment - L-Acoustics dV-DOSC Operator's Manual

3.4.1 Flown dV-DOSC, Ground Stacked SB Subwoofers (3-way system operation)

SB218 or SB118 subwoofers are normally ground stacked to take advantage of the 6 dB SPL
enhancement obtained due to floor coupling (effectively, there is a mirror image that doubles the
number of subwoofers). Various flown dV-DOSC and ground stacked subwoofer combinations are
shown in Figure 63 (see also Subwoofer Arraying Techniques).
Note: When SB subwoofers are physically separated from flown dV-DOSC arrays, 3WX presets are
recommended (80 Hz crossover point)
Left/Right Subwoofer Configuration Central Subwoofer Line Array
LCR Configuration

Figure 63: Flown dV-DOSC and ground stacked SB218 3-way system configurations

As illustrated in Figure 64, for flown dV-DOSC and ground stacked subwoofers, time alignment of
subwoofers is required due to the geometric path difference between the two systems. The distance
from the measurement microphone to the subwoofers is d while the distance to the flown dV-
SUB
DOSC system: distance(dV-DOSC) = distance(SUB) + PATH DIFFERENCE. Delaying subwoofers by
the geometric path difference is necessary to time align the subwoofers at the reference position.

Figure 64: Flown dV-DOSC and ground stacked subwoofer time alignment

Note: The geometric path difference should be added to the pre-alignment delay that already exists in the
standard presets (see Section 1.16 for further details).
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dV-DOSC dV-SUB Manual V3.0 June 2005