Electro-Voice Sx500+ User Manual

Page 2

Sx500+ 400-

att T

-W

ay Speaker System

Sx500+ 400-Watt Two-Way Speaker System

the woofer grille.

Speaker Protection

The Sx500+ like all other vented systems ex-

periences rapidly increasing cone excursion

below the box-tuning frequency, while the

acoustic output decreases rapidly. To ensure

a long woofer life even when used at high

power levels, it is recommended that some

form of electronics be used to control un-

necessary woofer cone excursion.

Graphic equalizers and active crossovers are

two methods that can be used to prevent low-

frequency signal below band-pass from go-

ing to the loudspeaker. When using an ac-

tive crossover, a high-pass filter with a cut-

off frequency of 32- to 45-Hz will provide

the necessary protection. The filter should

have a slope of at least 12 dB per octave.

Such subpass band filters are found in many

crossovers and equalizers manufactured by

Electro-Voice, as well as other commercially

available equipment.

Enclosure Construction

The Sx500+ enclosure is contructed of very

durable structural foam that is hard to dent,

scratch or break. The structural foam enclo-

sure allows for the high- and low-frequency

horns, the stand mount and the suspension

points to be molded into the enclosure. It also

allows for three handles to be integrated into

the enclosure.

Frequency Response

The combination of a 15-inch woofer, wide-

bandwidth high-frequency driver and an

equalized crossover results in the wide and

smooth overall response shown in Figure 1.

This response was measured at 3.05 meters

(10 feet), using a 4-volt swept sine-wave in-

put in an anechoic chamber using the inter-

nal passive crossover. No external equaliza-

tion was used. Figure 1 has been averaged

and corrected for 1 watt at 1 meter.

Connections and Biamping

The Sx500+ is equipped with two parallel

Neutrik Speakon

NL4MP connectors. In the

full-range mode, as supplied by the factory,

pins 1+ and 1– are the inputs to the system.

Another system can be connected in parallel

by using the other connector. Care must be

taken not to abuse the amplifier by connect-

ing impedances which are too low.

The user may put the system in biamp mode

by removing the input panel and moving a

connector from the full-range mode to biamp

mode, as noted on the crossover. In biamp

mode, 1+, 1– are the LF inputs and 2+, 2–

are the HF inputs.

Constant-Directivity Speaker System

The crossover frequency and speaker- com-

ponent geometries have been selected so that

the directional characteristics of the woofer

and constant-directivity high-frequency horn

match at the crossover frequency to create a

special system type — the constant-direc-

tivity system. At higher frequencies, the hori-

zontal coverage pattern remains constant and

the vertical pattern smoothly transitions to a

60° angle above 5,000 Hz. Response within

the 75° x 60° rated coverage angle is uni-

form, which means dependable audience

coverage without “hot spots” or dead zones

at certain frequencies. The 75° x 60° disper-

sion characteristic also helps avoid early re-

flections from nearby floor or side-wall sur-

faces which could degrade performance. The

controlled directivity of the high- and low-

frequency transducers also eliminates re-

sponse irregularities caused by diffraction off

nearby enclosure edges and, in combination

with an essentially flat on-axis frequency

response, produces a total acoustic power

output that is uniform with frequency.

Directivity

A unique feature of the Sx500+ is the con-

stant-directivity dispersion provided by the

75° x 60° horn. The polar response of the

system at selected one-third-octave band-

widths is shown in Figure 2. These polar re-

sponses were measured in an anechoic envi-

ronment at 6.1 meters (20 feet) using one-

third-octave pink-noise inputs. The frequen-

cies selected are fully representative of the

polar response of the system. Beamwidth of

the system utilizing the complete one-third-

octave polar data is shown in Figure 3. Di-

rectivity factor, R

and directivity index, D

are plotted in Figure 4.

Power-Handling Capacity

The Sx500+ is shipped in full-range mode

using an internal crossover. In biamp mode,

the long-term average power-handling ca-

pacity is as follows:

Low Frequency: 400 watts

High Frequency: 60 watts

Electro-Voice components and systems are

manufactured to exacting standards, ensur-

ing they will hold up, not only through the

most rigorous of power tests, but also

through continued 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 me-

chanical capabilities of the components.

Electro-Voice will support relevant addi-

tional 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 Sx500+ passes ANSI/EIA

RS-426-A 1980 with the following values:

R = 5.76 ohms (1.15 x (R

+ 1.86))

= woofer DCR

1.86 =horn-load impedance correction

E(MAX)

= 400 watts

Test voltage = 48.00 volts rms,

96.00 volts peak (+6 dB)

The “peak” power-handling capacity of a

woofer is determined by the peak test-volt-

age amount. For the Sx500+, a 96.00-volt

peak test-voltage translates into 1,600-watts

short-term peak power-handling capacity.

This is the equivalent of four times the “av-

erage” power-handling capacity, and is a

peak that can be sustained for only a few mil-

liseconds. However, this sort of short dura-

tion peak is very typical in speech and mu-

sic. 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 Capacity sec-

tion above, the Sx500+ has a random-noise power