S-40
Compact Monitor
Description
The Electro-Voice S-40 is an extremely com-
pact high- performance monitor loudspeaker
system. It is ideally suited for indoor or out-
door applications requiring high-quality
sound reproduction. As a near-field moni-
tor 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 loud-
speaker for nearfield monitoring in live per-
formance situations. Threaded inserts in the
cabinet in combination with the optional
mounting hardware provide a flexible
mounting system for virtually any applica-
tion.
The low-frequency section is a 5-1/4" di-
rect-radiating woofer with a polypropylene
cone installed in an optimally vented high-
impact polystyrene enclosure. This combi-
nation 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 au-
tomatically reduce the power being delivered
to the drivers if their threshold is exceeded,
greatly reducing the possibility of driver fail-
ure.
Both drivers feature low-flux-leakage de-
signs enabling the speaker to be used in close
proximity to video monitors. For very criti-
cal video monitoring applications, a mini-
mum distance of four inches from the edge
of the loudspeaker to the edge of the CRT is
recommended.
Frequency Response
The combination of 5-1/4" 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-oc-
tave averaged and no external equalization
was used.
Directivity
The polar response of the S-40 speaker sys-
tem 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 represen-
tative of the polar response of the system.
Beamwidth of the system utilizing the com-
plete 1/3-octave polar data is shown in Fig-
ure 2. R
q
(Q) and directivity index (D
i
) are
plotted in Figure 3.
Power Handling Capacity
To our knowledge, Electro-Voice was the
first U.S. manufacturer to develop and pub-
lish a power test closely related to real-life
conditions. First, we use a random noise
input signal because it contains many fre-
quencies simultaneously, just like real voice
or instrument program. Second, our signal
contains more energy at extremely high and
