Martin Audio W8L Longbow Application Manual page 22

Whilst the above response may look good on a plot, the response in the near-field is a bit
ragged and subjective experience dictates that a slight decrease in level with distance is
desirable. A system with, say, +4dB at the front smoothly decreasing to -4dB at the back
will sound more natural as long as background noise is not problematic.
The following progressive cur vature array has a more natural coverage characteristic.
Smoother coverage from a progressive curvature array (including down-fills) –
Band-zoning
Air absorption can cause excess high frequency attenuation which can seriously limit far-
field performance unless compensation is used. Air absorption is most serious around
20% RH (relative humidity) – although the effect varies with temperature and
atmospheric pressure.
Mid and high frequency boost are applied to the upper sections of an array to compensate
for air losses. Again, a completely flat level and amplitude response will sound unnatural
in the far-field. As ment ioned earlier, an acceptable overall level range is ±4dB. An
acceptable amplitude response is between flat and slightly pink (a falling response with
frequency by up to 0.8dB per octave).
For more information on band-zoning, see the information on
relevant W8L Longbow,
DISPLAY™ simulation
W8LC or W8LM quick start section.
System control
All material © 2007. Martin Audio Ltd. Subject to change without notice.
or the