Martin Audio W8L Longbow Application Manual page 78

5.7.2 Front fill placement and alignment
Placement
Other loudspeakers in the Wavefront range may be used as stage apron fills to
augment W8L Series line array systems.
When positioned on a radius from the downstage centre vocal area and synchronised
with the lower line array section, these apron fills don't just balance the sub woofers.
They focus vocals and add a detailed quality that can be beneficial right out to the mix
position.
Image alignment
If the apron fill signal is delayed by the difference between the down- fill propagation
time and the apron fill propagation time and attenuated by the ratio of those
propagation times, the sound will appear to come from an area in between the two
systems for the listener shown.
Apron fill delay line setting = t down- fill - t apron fill (2.91ms for each metre)
Set apron fill gain so that image appears to come from artist's position
All material © 2007. Martin Audio Ltd. Subject to change without notice.