Electro-Voice S-40 ユーザーズマニュアル

S

-40 Compact Monitor

S-40 Compact Monitor

2

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 reliabil-

ity (cone and diaphragm excursion).  Note

that the sine wave test signals sometimes

used have a much less demanding peak value

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 with-

stand the power test described in the revised

EIA Standard RS-426A.  The EIA test spec-

trum 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 band-

width in Hz) is fed to a shaping filter with 6-

dB-per octave  slopes below 40 Hz and above

318 Hz.  When measured with the usual con-

stant-percentage bandwidth analyzer (one-

third 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 120 watts into the 3.2 ohms EIA

equivalent impedance, (19.6 volts true

RMS).  Amplifier clipping sets instantane-

ous peaks at 6 dB above the continuous

power, or 480 watts peak (39.2 volts peak).

This procedure provides a rigorous test of

both thermal and mechanical failure modes.

Both the woofer and the tweeter employ in-

dependent 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

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.

On the back of the S-40 are (2) 1/4"-20

threaded inserts. These are intended to be

used with mounting systems which have 2-

3/8" mounting centers, such as the

Omnimount Systems Series 25.

A U-type bracket, the S-40MB is also avail-

able.  This will allow the S-40 to be mounted

on walls or ceilings.  A microphone stand

adaptor is also included.  Complete mount-

ing instructions are included with the S-

40MB.

Care should be taken to ensure that the cho-

sen fixing point is strong enough to support

the S-40.  Care should also be taken to en-

sure 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 book-

shelf, then the rubber feet that are included

with the S-40 should be attached to the

speaker. If the speaker is placed on the bot-

tom side, then a rubber foot should be at-

tached 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 ori-

entation is used.

The loudspeaker shall be a two-way system

consisting of a 13 cm (5-1/4") low-frequency

loudspeaker, 2.5 cm (1 inch) high-frequency

loudspeaker and frequency dividing network

installed in a vented enclosure.  The divid-

ing network crossover frequency shall be

3,500 Hz.  The dividing network shall in-

clude protection circuits for both the low-

frequency loudspeaker and the high-fre-

quency loudspeaker.  The loudspeaker sys-

tem shall meet the following performance

criteria: Power handling, 120 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 meas-

ured at a distance of one meter on axis.  Im-

pedance, 4 ohms nominal, 3.7 ohms mini-

mum.  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 Electro-

Voice model S-40.

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. Ex-

clusions 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 Electro-

Voice Service or any of its authorized ser-

vice representatives. Obtaining Warranty

Service: To obtain warranty service, a cus-

tomer must deliver the product, prepaid, to

Electro-Voice Service or any of its autho-

rized service representatives together with