Martin Audio WLXGS User Manual page 32

Note that it is important to keep the subwoofers tightly packed to avoid polar anomolies caused by spacing.
Procedure
The normal procedure is to measure the angle from the top of the vertical subwoofer stack to the highest/most
distant seats (using an inclinometer) and to calculate the required delay increment with the formula shown.
Example
We wish to project bass/mid-bass punch to stadium balcony seats 30º higher than the top of our WLX stacks.
The WLXs are 490mm wide giving a centre-to-centre spacing of 0.49m.
This means that our delay increment (in ms)
All material © 2007. Martin Audio Ltd. Subject to change without notice.
= tan 30º x 0.49 x 1000
340
= 0.577 x 0.49 x 2.94
= 0.83mS or 830uS.