Advertisement
ternal equalization was used. Figure 1 has been
averaged and normalized to 1 watt at 1 meter.
Connections
The S18 is equipped with two parallel 1/4-inch
phone jacks. (The S18-E has two parallel
®
Neutrik Speakon
NL4MP connectors.) An-
other woofer can be connected in parallel by
using the other connector. Care must be taken
not to abuse the amplifier by connecting im-
pedances which are too low. (See amplifier
specifications supplied by the manufacturer.)
Power-Handling Capacity
Electro-Voice components and systems are
manufactured to exacting standards, ensuring
they will hold up, not only through the most
rigorous of power tests, but also through con-
tinued use in arduous, real-life conditions. The
EIA Loudspeaker Power Rating Full-Range
(ANSI/EIA RS-426-A 1980) uses a noise
spectrum which mimics typical music and tests
the thermal and mechanical capabilities of the
components. Electro-Voice will support rel-
evant additional standards as and when they
become available. Extreme, in-house power
tests, which push the performance boundaries
of the woofers, are also performed and passed
to ensure years of trouble-free service.
Specifically, the S18 passes ANSI/EIA RS-
426-A 1980 with the following values:
R
= 5.87 ohms (1.15 x R
SR
P
= 300 watts
E(MAX)
Test voltage = 41.96 volts rms,
83.93 volts peak (+6 dB)
The "peak" power-handling capacity of a
woofer is determined by the peak test voltage
amount. For the S18, a 84.8-volt peak test
voltage translates into 1,200-watts short-term
peak power-handling capacity. This is the
equivalent of four times the "average" power-
handling capacity, and is a peak that can be
sustained for only a few milliseconds. How-
ever, this sort of short-duration peak is very
typical in speech and music. Provided the
amplifier can reproduce the signal accurately,
without clipping, the woofer will also perform
accurately and reliably, even at these levels.
Amplifier Power Recommendations
As noted in the Power-Handling section,
above, the S18 has a random-noise power ca-
pacity of 300 watts long term (1,200 watts
peak) per ANSI/EIA RS-426-A 1980. The
following guidelines will help relate this to
an appropriate power amplifier output rating.
1. To use the S18 to full capacity, skilled
experts in sound system installation and
operation will obtain the best results if
the power amplifier is 2.0 to 4.0 times
the long-term average noise power rat-
ing of the speaker system. For the S18
this is 600 to 1,200 watts.
The caution cannot be made strongly
enough, however, that this arrange-
ment is only for experts or those who
can discipline themselves against
"pushing" the system for ever-higher
sound levels and who can avoid "acci-
dents" such as catastrophic feedback
or dropped microphones.
At these levels the system will fail if
pushed beyond these limits even for a
short time. It should be used by ex-
perts only or with a known signal
source such as CD's which do not feed-
back or do not have unknown signals
present.
2. A more conservative, "normal" amplifier
size, which will produce audible results
nearly equal to those of the "expert" rec-
ommendation, is 1.0 to 1.4 times the
long-term average noise power rating of
)
the speaker. For the S18 this is 300 to
E
420 watts.
3. To be very conservative, one can use an
amplifier rated at 0.5 to 0.7 times the
long-term average noise power rating of
the loudspeaker. For the S18 this is 150
to 210 watts.
See Speaker Protection section.
Request P.A. Bible Addition No. Two
("Power Handling Capacity") for more back-
ground on these recommendations.
Service
In the unlikely event the S18 requires ser-
vice, the woofer can be replaced or serviced
from the front. A service data sheet is avail-
able from Electro-Voice.
Architects' and Engineers'
Specifications
The loudspeaker shall be a compact vented-
box type. The low frequencies shall be re-
produced with one 300-watt (ANSI/EIA RS-
426-A 1980) SG18 457-mm (18-in.) woofer.
The system will reproduce the frequencies
from 45 to 3,300 Hz. The system shall be
capable of producing average sound levels
in excess of 123 dB in the long term, and
short-term peaks of 129 dB.
The enclosure shall be constructed of black-
TM
carpeted Road-Wood
and have a metal
grille which attaches with 7 screws. The
dimensions shall be 778 mm (30.7 in.) tall,
505 mm (19.9 in.) wide, and 464 mm (18.3 in.)
deep. The system shall weigh 27.7 kg (61 lb).
Two 1/4-inch phone jack connections shall
be provided. (Two Neutrik Speakon
nections shall be provided on the "E" ver-
sion.)
The loudspeaker system shall be the Elec-
tro-Voice S18 (or S18-E).
Uniform Limited Warranty
Electro-Voice products are guaranteed
against malfunction due to defects in mate-
rials or workmanship for a specified period,
as noted in the individual product-line
statement(s) below, or in the individual prod-
uct data sheet or owner's manual, beginning
with the date of original purchase. If such
malfunction occurs during the specified pe-
riod, the product will be repaired or replaced
(at our option) without charge. The product
will be returned to the customer prepaid.
Exclusions and Limitations: The Limited
Warranty does not apply to: (a) exterior fin-
ish or appearance; (b) certain specific items
described in the individual product-line
statement(s) below, or in the individual prod-
uct data sheet or owner's manual; (c) mal-
function resulting from use or operation of
the product other than as specified in the
product data sheet or owner's manual; (d)
malfunction resulting from misuse or abuse
of the product; or (e) malfunction occurring
at any time after repairs have been made to
the product by anyone other than Mark IV
Audio Service or any of its authorized ser-
vice representatives. Obtaining Warranty
®
con-
Advertisement
