Model and quantity for a balanced spectral response
A spectrally balanced system will provide a useful far-field response within an octave
of the product’s LF and HF specification.
A system’s LF response may be enhanced by extending the effective column length
with sub-woofers flown above or stacked immediately below the array.
HF air absorption is the dominant factor beyond 50m. Be cautious about specifying
very long throw systems where the air may be dry (e.g. for outdoor events during hot,
dry weather, for desert regions or for venues with warm air heating). See Sections 5.8
&
Section 5.9.
The following chart indicates the minimum quantity and model for the required
throw. The chart is based on applications experience and line array physics as it is
currently understood.
Quantity W8L
(no subs)
W8LC
(no subs)
W8LM
(no subs)
Cabinets
arrayed with
2° or less
inter-cabinet
splay
Throw
(in meters)
for spectral
balance
Throw
(in meters)
for spectral
balance
Throw
(in meters)
for spectral
balance
4 25 18 12
6 40 29 18
8 60
*
40 25
10 80* 58* 32
12 100* 70* 41
14 130** 88* 50*
16 155** 105** 60*
* Assumes relative humidity 50% or higher
** Assumes relative humidity 70% or higher
Lower humidity will cause unacceptable HF absorption.
Note: The cabinet quantities refer to low curvature
arrays or the low curvature (upper)
sections of progressively curved arrays.
The following ViewPoint
tm
examples indicate the quantity of cabinets that can be
regarded as contributing to the system’s mid and high frequency far-field
characteristic.