Description
The Electro-Voice Sb180 is a 600-watt sub-
woofer loudspeaker system which combines
the attributes of both horn-loaded and
vented-box designs. It utilizes the unique
SubScoop
TM
cabinet construction with a
EVX-180B woofer, as used in the X-Array
®
concert systems. The design behaves like a
horn over much of its range, but without the
time delay and weight problems usually as-
sociated with conventional designs. Vented-
box principles take over for the lowest oc-
tave and assist in producing exceptionally
high levels of clean, punchy bass from a sub-
compact box. The reverse woofer orienta-
tion has been used to optimize the rear cham-
ber volume and decrease the horn flare rate
for extended low-end performance.
The Sb180 can be used to augment the bass
performance of any Electro-Voice stage sys-
tem. (This may involve the use of appropri-
ate electronics and crossovers.) A 1
3
/
8
-in.
stand-mount receptacle on the top surface of
the Sb180 allows satellite speaker systems
such as the Sx500 and Sx300 to be used (see
Figure 4). A 34-inch mounting pole is in-
cluded with the Sb180.
Use in Multiples
The Sb180 may be used in multiples to in-
crease acoustic output. A 6-dB increase in
maximum acoustic output occurs when two
speaker systems are placed side by side and
paralleled, yielding a 4-ohm load. For op-
eration at very-low frequencies, the woofer
cones “mutually couple,” acting as one sys-
tem with twice the effective cone area and
power-handling capacity of a single system.
Increasing the cone area doubles the effi-
ciency, providing a 3-dB increase in sound
pressure level. The doubled power capacity
provides the potential for an additional 3-dB
gain in maximum acoustic output.
Mutual coupling occurs when the frequency
is such that the center-to-center distance be-
tween the two woofer manifolds is less than
about one-half wavelength. When the dis-
tance is greater than one-half wavelength,
as would occur if two Sb180’s were widely
spaced, the level increase tends to be lim-
ited to the 3-dB power-handling increase.
The woofer is connected using one of the
Neutrik Speakon
®
jacks marked “input.”
Electro-Voice recommends the Neutrik
NL4MPR-V connector be used in most high-
power situations. A parallel woofer can be
connected using the other connector. Care
must be taken not to abuse the amplifier by
connecting impedances which are too low.
Crossovers and Amplifiers
To optimize performance, the Sb180 should
be used in conjunction with an active cross-
over with a minimum slope of 12-dB per oc-
tave and a crossover frequency in the range
of 100 to 250 Hz. Due to the high efficiency
of the Sb180, less amplifier input is needed
to achieve a given sound output level. The
high power-handling capacity of the Sb180
permits the use of amplifiers with a rating of
up to 1,200 watts rms into 8 ohms.
Speaker Protection
When in the vented-box mode, the
SubScoop,
TM
like all other vented systems,
experiences rapidly increasing cone excur-
sion below the box-tuning frequency. The
acoustic output is also decreasing rapidly;
therefore, it is sensible to protect the Sb180
and maximize the power output of the sub-
woofer by inserting an active 32-Hz high-
pass filter with a slope of at least 12-dB per
octave into the circuit. Such subpassband fil-
ters are found in many commercially avail-
able crossovers and equalizers including
items manufactured by Electro-Voice.
Subwoofer
• EVX-180B woofer for reliable,
extended low-frequency output
• Subwoofer for augmenting the
low-frequency performance of EV
stage systems
• Natural high-frequency roll-off
• 600-watt continuous, 1,200-watt
program power capacity
• Rugged, road-ready cabinet,
metal grille, and painted finish
• Neutrik Speakon
®
inputs
• 1 3/8-inch stand mount in top
allows use of satellite system
• 34-inch long 1 3/8-inch mounting
pole included
Sb
180
