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Distortion Response 10% Rated Input
Power at 100 Hz (on axis at 1 meter from
system; see Figure 5),
Second Harmonic,
50 Hz: 9.0%
80 Hz: 5.0%
200 Hz: <1.0%
Third Harmonic,
50 Hz: 3.5%
80 Hz: 1
.3%
200 Hz: <1.0%
Transducer Complement,
Low Frequency:
EVX150A 381-mm (15-in.) woofer
in a vented enclosure
Box Tuning Frequency,
Normal:
38Hz
Step-Down:
27 Hz
Polarity:
A positive voltage applied to the positively
marked input terminal produces a positive
acoustic pressure at the front of the
system
Input Connections:
#10 screw terminals on barrier strip; each
driver can be individually accessed
Enclosure Materials and Color:
Textured black painted 7-ply void-free
birch
Grille:
Black powder coated, vibration-resistant
steel, removable
Suspension:
Integral three-point flying system (accepts
Ancra 42546-10 single-stud tie-down cargo
fitting; four fittings supplied with system;
see Suspending PIM-151 Enclosures
section)
Dimensions (see Figure 6),
Height:
911 mm (35.9 in.)
Width at Front:
575 mm (22.7 in.)
Width at Rear:
359 mm (14.1 in.)
Depth:
438 mm (17.2 in.)
Side-Wail Draft Angle:
15°
Net Weight:
34.0 kg (75 Ib)
Shipping Weight:
40.0 kg (85 Ib)
DESCRIPTION AND APPLICATIONS
The Electro-Voice PIM-151 is a compact, trap-
ezoidallow-frequency speaker system for per-
manentinstallation. A 15-inchwooferismounted
in an optimally vented enclosure. The PIM-151
is part of the PI Matrix Series
Tt ",
a highly flexible
group of full-range and low-frequency systems
for applications where compact systems are
appropriate. Many performing arts centers,
clubs, auditoriums, sports facilities and houses
of worship are candidates for the PI Matrix
Series
Tl
• 4 •
The flexibility of the PI Matrix Series™ allows
the designer to customize a system to both suit
the acoustic environment and meet a wide
variety of architectural and mechanical require-
ments.
PIM-151 options include low-frequency driv-
ers, enclosure materials and finish, grilles,
suspension hardware and input-panel con-
nections, giving the sound contractor or con-
suitant literally thousands of combinations to
satisfy the overall system design criteria.
The PIM-151 standard configuration employs
the EVX-150A 381-mm (15-inch) long-throw,
extended-reliability woofer. Operating between
45 and 1,800 Hz in a compact enclosure, the
EVX-150A can handle very high levels of input
power, producing high acoustic output with
relatively low distortion.
The PIM-151 is equipped with a number of
additional features to make operation and
in-
stallation easy and secure. A proprietary struc-
tural extrusion is incorporated into the enclo-
sure, providing safe and flexible suspension
(see Suspending PIM-151 Enclosures section).
Up to two enclosures of the same footprint can
be suspended without additional support (as
long as the lower system is not heavier than the
upper system), so arrays can be created quickly
and easily. The grille is composed of vibration-
resistant steel for excellent driver protection,
and an optional foam cover can be added for
better protection when used outdoors. Besides
the standard black-painted finish, the enclo-
sure can also be ordered primed in white for
painting with ordinary paints, unfinished for
staining or with our special Wolverine<!>weather-
resistant finish for outdoor applications. The
PIM-151 driver can be serviced from the front of
the enclosure.
A complete listing of all system options Is
shown In Figure 1.
SUSPENDING PIM-151 ENCLOSURES
Suspending any object is potentially danger-
ous and should be attempted only by individu-
als who have
a
thorough knowledge of the
techniques and regulations of hanging over-
head. Electro- Voice strongly recommends that
the PIM-151 be suspended taking into account
all current national, federal, state and local
regulations. It is the responsibility of the in-
staller to ensure that the PIM-151 is safely
installed in accordance with all such regula-
tions. If the PIM-151 is suspended, Electro-
Voice strongly recommends that the system be
inspected at least once
a
year. If any sign of
weakness or damage is detected, remedial
action should be taken immediately.
The PI Matrix Series™ enclosures are sus-
pended using the following approach, which
has been approved by an independent struc-
tural engineer. Every enclosure incorporates
six independent suspension points, three on
the top and three on the bottom. A minimum of
three points must be used at all times to sus-
pend the enclosure. The suspension points,
which "tie" the top and sides of the enclosure
together, are made of structural
aluminum.
Each suspension point mates to an Ancra
42546-10 locking fitting (four are supplied with
each enclosure ordered with this option, EV
#20562), and each point has a break strength of
907 kg (2,000 Ib) in any direction.' A maximum
of two enclosures can be
"daisy
chained" to-
gether, allowing the construction of vertical
arrays. This also applies to other PIM models
with the same footprint, as long as the lower
system is no heavier than the upper system. If
the lower system is heavier, or
if
longer arrays
are required, provision must be made to inde-
pendently suspend each enclosure. The Ancra
42546-10 fitting incorporates a safety pin to
prevent accidental release, and it should be
engaged at all times.
CONNECTIONS
Depending on the option ordered, barrier strip
or Neutrik Speakon<!> connectors are used for
input connections. Both barrier strips are wired
in parallel and connected to the single woofer.
In the Speakon<!> connector options, pins 1
+/1-
and 2+/2- are in parallel and connected
to
the
woofer. The driver
is
connected so that a posi-
tive voltage applied to the positively marked
terminal will produce a positive acoustic pres-
sure at the front of the system.
FREQUENCY RESPONSE
PIM-151 axial frequency response was mea-
sured
in
Electro-Voice's large anechoic cham-
ber at a distance of 3.0 meters (10 feet) with
swept sine-wave input. Figure 2 shows the
typical system response, with a 4-volt drive,
normalized for a 1-watt input and a 1-meter
distance.
DIRECTIVITY
The directional characteristics of the PIM-151
were measured in Electro-Voice's large
anechoic chamber, with a test signal of one-
third-octave filtered pink noise at the frequen-
cies
indicated.
A full spherical measurement
system, which is fully compatible with Mark IV
Audio's AcoustaCADDTM computer-aided
de-
sign program, was used. All directional infor-
mation was measured at 6.1 meters (20 feet).
Figure 7
illustrates
the nominal horizontal and
vertical polar responses, with the long system
axis vertical.
Figure 3 illustrates the horizontal and vertical
beamwidths. Beamwidth is the angle at which
the horizontal and vertical polar responses
have decreased in level by 6 dB when com-
pared to the on-axis frequency response.
Figure 4
represents
the total directivity of the
PIM-151. The directivity factor, Re (Q), is the
relative value, at a point, when compared to an
ideal spherical response. The directivity index
(0,) is calculated by 0,
=
1010g,oR.
SERVICE
In the unlikely event the PIM-151 requires ser-
vice, the driver can be replaced or serviced
from
the
front. A service data sheet is available
from Electro-Voice.
POWER-HANDLING TEST
Electro-Voice components and systems are
manufactured
to
exacting standards, ensuring
they will hold up, not only through the most
rigorous
of power tests, but also through contin-
ued use
in
arduous, real-life conditions. Two
main test specifications are used: the AES
Recommended Practice for Specification of
LoudspeakerComponents Used in Professional
Audio and Sound Reinforcement (AES2-19841
ANSI S4.26-1984) and the EIA Loudspeaker
Power Rating Full Range (EIA RS-426-A 1980).
Both of these specifications use random-noise
spectrum which mimics typical music and tests
the thermal and mechanical capabilities of the
components. Electro-Voice will support relevant
additional standards as and when they become
available.
Extreme, in-house power tests, which
push the performance boundaries of the com-
ponents, are also performed and passed to
ensure years of trouble-free service.
The PIM-151 passes EIA RS-426-A 1980 with
the following
values:
R~A
=
5.8 ohms (1.15 x R
E )
P
E(max)
=
600 watts
Test voltage
=
59.0 volts rms
118 volts peak (+6 dB)
STEP-DOWN
Step-down is a method of extending the low-
frequency
response
by increasing the power
input
to
the
system instead of the enclosure
volume.
In
step-down mode, the enclosure is
tuned to 0.707 the normal frequency. This
increases the output at the new tuning fre-
quency and reduces the output at the original
tuning frequency. This smoothly falling ampli-
tude response can be equalized to obtain a new
3-dB-down point in the region of 0.7 that of the
original. To obtain a similar response without
step-down would require an enclosure with at
least twice the volume.
1. For additional
information,
contact Ancra International
at
6061371-7272
ortoll free (within U.S. only) at
8001233·5138.
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