Martin Audio W8L Longbow Application Manual page 54

to the top.
To avoid the confusion of two numbering standards, we use the traditional top-down
number standard for the individual cabinets and a bottom- up lettering standard for band-
zoning groups. See the SPEAKER O/P GROUP column. Group A is at the bottom of the
array and drives the bottom two loudspeakers 15 & 16.
W8L Series impedances and grouping
W8L Longbow and W8LC line array section impedances are all 8 ohms and usually
driven in pairs so that each power amplifier channel sees a 4 ohm load. W8LM line array
section impedances are about 13 ohms and are usually driven in fours to present a 3.25
ohm load.
Multipurpose racks are easily configured for a wide variety of array sizes by using this
bottom- up lettering scheme. Smaller line array configurations can be driven from large
multipurpose racks by leaving the upper, more equalized, outlets unused.
The following example relates bottom- up rack outlet lettering to traditional top-down
cabinet numbering for 16-cab and 8-cab systems.
Note that W8L Longbows and W8LCs are driven in pairs (8ohms//8ohms = 4ohms)
whereas W8LMs are driven in fours (13ohms//13ohms//13ohms//13ohms = 3.25ohms).
Speaker W8L,
Outlet Longbow
or W8LC
16-cab
system
(paralleled
in pairs)
H 1&2
G 3&4
F 5&6
E 7&8
D 9&10
C 11&12
B 13&14
A 15&16
W8L, W8L,
Longbow Longbow
or W8LC or W8LC
8-cab 4-cab
system system
(paralleled (paralleled
in pairs) in pairs)
1&2
3&4
5&6 1&2
7&8 3&4
W8LM W8LM
16-cab 8-cab
system system
(paralleled (paralleled
in fours) in fours)
1-4
5-8
9-12 1-4
13-16 5-8
All material © 2007. Martin Audio Ltd. Subject to change without notice.
W8LM
4-cab
system
(paralleled
in fours)
1-4