Martin Audio WLXGS User Manual page 29

These lobes could cause low frequency feedback problems on stage with the high microphone gains used for
orchestral low string (cello, double bass) sections or for "unplugged" performances.
At 60Hz the spacing is an odd number of half-wavelengths again so we see side nulls again.
When the frequency drops to 40Hz, the 8.6m spacing = 1 wavelength.
Again, the central response is maintained but there is a dip in response over wide areas either side of the
centre. The spacing is an even number of half-wavelengths again so we see side lobes again.
All material © 2007. Martin Audio Ltd. Subject to change without notice.
60Hz
40Hz