Electro-Voice S-40 EDS User Manual
S-40
Compact Monitor
Description
The Electro-V oice S-40 is an extremely compact high- performance monitor loudspeaker
system. It is ideally suited for indoor or outdoor applications requiring high-quality
sound reproduction. As a near-field monitor in control rooms or broadcast studios, or
as a foreground or background loudspeaker
in restaurants and clubs, the S-40 is the
choice of professional users. Its high power
handling also makes the S-40 an ideal loudspeaker for nearfield monitoring in live performance situations. Threaded inserts in the
cabinet in combination with the optional
mounting hardware provide a flexible
mounting system for virtually any application.
The low-frequency section is a 5•-in. direct-radiating woofer with a polypropylene
cone installed in an optimally vented highimpact polystyrene enclosure. This combination produces an exceptionally extended
bass response with relatively high efficiency
for an extremely small enclosure. The use
of plastic materials for the enclosure and cone
allow the loudspeaker system to be used in
high-humidity environments.
The high-frequency section is a 1-in. direct-
radiating soft dome tweeter. The tweeter is
ferro-fluid cooled and uses flexible tinsel
lead wires to prevent thermal or mechanical
failure. These features in addition to the large
magnetic system make this the most rugged
tweeter ever used in a system this size.
These high quality components will provide
years of listening pleasure when driven at
reasonable levels. However, sometimes
loudspeakers are accidently over-driven,
causing the drive units to fail. To prevent
against this, EV engineers have incorporated
independent woofer and tweeter protection
circuits in the S-40. These circuits will automatically reduce the power being delivered
to the drivers if their threshold is exceeded,
greatly reducing the possibility of driver failure.
Both drivers feature low-flux-leakage designs enabling the speaker to be used in close
proximity to video monitors. For very critical video monitoring applications, a minimum distance of four inches from the edge
of the loudspeaker to the edge of the CRT is
recommended.
Frequency Response
The combination of 5•-in. woofer, 1-inch
tweeter and optimized crossover result in the
wide and smooth frequency response shown
in Figure 1. This response was measured at
1 meter, using a 2 Volt (1 watt) input in an
anechoic chamber. The response is 1/3-octave averaged and no external equalization
was used.
Directivity
The polar response of the S-40 speaker system at selected 1/3-octave bandwidths is
shown in Figure 4. These polar responses
were measured in an anechoic environment
at 10 feet using 1/3-octave pink noise inputs.
The frequencies selected are fully representative of the polar response of the system.
Beamwidth of the system utilizing the complete 1/3-octave polar data is shown in Figure 2. R
plotted in Figure 3.
Power Handling Capacity
To our knowledge, Electro-Voice was the
first U.S. manufacturer to develop and publish a power test closely related to real-life
conditions. First, we use a random noise
input signal because it contains many frequencies simultaneously, just like real voice
or instrument program. Second, our signal
contains more energy at extremely high and
(Q) and directivity index (Di) are
q
S-40 Compact Monitor
low frequencies than typical actual program,
adding an extra measure of reliability. Third,
the test signal includes not only the overall
“long-term average” or “continuous” level which our ears interpret as loudness - but also
short- duration peaks which are many times
higher than the average, just like the actual
program. The long-term average level
stresses the speaker thermally (heat). The
instantaneous peaks test mechanical reliability (cone and diaphragm excursion). Note
that the sine wave test signals sometimes
used have a much less demanding peak value
S-40 Compact Monitor
relative to their average level. In actual use,
long-term average levels exist from several
seconds on up, but we apply the long-term
average for several hours, adding another
extra measure of reliability.
Specifically, the S-40 is designed to withstand the power test described in the revised
EIA Standard RS-426A. The EIA test spectrum is applied for eight hours. To obtain
the spectrum, the output of a white noise
generator (white noise is a particular type of
random noise with equal energy per bandwidth in Hz) is fed to a shaping filter with 6dB-per octave slopes below 40 Hz and above
318 Hz. When measured with the usual constant-percentage bandwidth analyzer (onethird octave), this shaping filter produces a
spectrum whose 3-dB-down points are at 100
Hz and 1200 Hz with a 3-dB-per octave slope
above 1200 Hz. This shaped signal is sent
to the power amplifier with the continuous
power set at 160 watts into the 3.2 ohms EIA
equivalent impedance, (22.6 volts true
RMS). Amplifier clipping sets instantaneous peaks at 6 dB above the continuous
power, or 640 watts peak (45.2 volts peak).
This procedure provides a rigorous test of
both thermal and mechanical failure modes.
Protection Circuitry
Both the woofer and the tweeter employ independent protection circuits to prevent
against accidental overdrive and improve
system reliability. In the woofer circuit, a
solid state self-resetting switch is activated
once the safe level to the woofer is exceeded
(approximately 60 watts). This switch then
inserts a high positive current coefficient
resistor (HPCCR) in series with the woofer.
The resistance of the HPCCR increases as
2
the drive level to the woofer increases and
limits the power being delivered to the
woofer. The HPCCR is similar to a lamp
and will produce light that is visible thru the
port when activated. This is an indication to
reduce the gain of the power amp if output
compression is to be avoided. The maximum
acoustic output is achieved just before the
protection circuit is activated.
The tweeter protection circuit behaves in a
similar manner, except a fixed resistor is used
in place of the HPCCR which attenuates the
power to the tweeter by approximately 6 dB.
Installation Notes
On the back of the S-40 are two •-20"
threaded inserts. These are intended to be
used with mounting systems which have 23/8" mounting centers, such as the
Omnimount Systems Series 25.
A U-type bracket, the S-40MB is also available. This will allow the S-40 to be mounted
on walls or ceilings. A microphone stand
adaptor is also included. Complete mounting instructions are included with the S40MB.
Care should be taken to ensure that the chosen fixing point is strong enough to support
the S-40. Care should also be taken to ensure that the S-40 is not exposed to direct
precipitation.
If the speaker system is not used with one of
the mounting brackets, such as on a bookshelf, then the rubber feet that are included
with the S-40 should be attached to the
speaker. If the speaker is placed on the bottom side, then a rubber foot should be attached to each of the two rear corners only.
This will compensate for the 3° draft that is
molded into the cabinet, and allows the baffle
to sit perpendicular to the surface that the
speaker is placed on. If the speaker is to be
placed on its side, then a rubber foot should
be attached to each of the four corners. The
nameplate that is attached to the grille may
be rotated depending on which mounting orientation is used.
Architects' and Engineers'
Specifications
The loudspeaker shall be a two-way system
consisting of a 13 cm (5•-in.) low-frequency
loudspeaker, 2.5 cm (1 inch) high-frequency
loudspeaker and frequency dividing network
installed in a vented enclosure. The dividing network crossover frequency shall be
3,500 Hz. The dividing network shall include protection circuits for both the lowfrequency loudspeaker and the high-frequency loudspeaker. The loudspeaker system shall meet the following performance
criteria: Power handling, 160 watts per EIA
RS-426A. Frequency response, … 3 dB from
85 Hz to 20 kHz. Pressure sensitivity, 85
dB SPL at one watt, 100 Hz to 10 kHz measured at a distance of one meter on axis. Impedance, 4 ohms nominal, 3.7 ohms minimum. The enclosure shall be molded of high
impact polystyrene structural foam. The unit
shall be 24.9 cm (9.8 inch) high, 17.8 cm
(7.0 inch) wide, 15.0 cm (5.9 inch) deep. The
loudspeaker system shall be the ElectroVoice model S-40.
Limited Warranty
Electro-Voice products are guaranteed
against malfunction due to defects in materials or workmanship for a specified period,
as noted in the individual product-line
statement(s) below, or in the individual product data sheet or owner’s manual, beginning
with the date of original purchase. If such
malfunction occurs during the specified period, the product will be repaired or replaced
(at our option) without charge. The product
will be returned to the customer prepaid. Ex-
clusions and Limitations: The Limited
W arranty does not apply to: (a) exterior finish or appearance; (b) certain specific items
described in the individual product-line
statement(s) below, or in the individual product data sheet or owner’s manual; (c) malfunction 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 ElectroVoice Service or any of its authorized service representatives. Obtaining Warranty
Service: To obtain warranty service, a customer must deliver the product, prepaid, to
Electro-Voice Service or any of its authorized service representatives together with
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