USM-P Series
Self-Powered Loudspeaker Systems
OPERATING INSTRUCTIONS
USM-1P
USM-100P
Superior
engineering
for the art
and science
of sound.
Keep these important operating instructions.
!
SAFETY SUMMARY
endroit où il y a de l’eau ou une
humidité excessive.
ENGLISH
• Um ein Überhitzen dem Lautsprecher
zu verhindern, das Gerät vor direkter
Sonneneinstrahlung fernhalten und
nicht in der Nähe von wärmeab-
strahlenden Haushaltsgeräten (z.B.
Heizgerät oder Herd) aufstellen.
• Im Inneren diesem Lautsprecher herr-
schen potentiell gefährliche
• To reduce the risk of electric shock,
disconnect the loudspeaker from the
AC mains before installing audio
cable. Reconnect the power cord only
after making all signal connections.
• Connect the loudspeaker to a two-
pole, three wire grounding mains
receptacle. The receptacle must be
connected to a fuse or circuit breaker.
Connection to any other type of
receptacle poses a shock hazard and
may violate local electrical codes.
• Do not install the loudspeaker in wet
or humid locations without using
weather protection equipment from
Meyer Sound.
• Ne pas laisser de l’eau ou tout objet
pénétrer dans l’haut-parleur. Ne pas
placer de r´cipients contenant un liq-
uide sur cet appareil, ni à proximité
de celui-ci.
• Pour éviter une surchauffe de l’haut-
parleur, conserver-la à l’abri du soleil.
Ne pas installer à proximité d’ap-
pareils dégageant de la chaleur tels
que radiateurs ou appareils de
chauffage.
Spannungen. Nicht versuchen, das
Gerät zu öffnen. Es enthält keine vom
Benutzer reparierbaren Teile.
Reparaturen dürfen nur von ausge-
bildetem Kundenienstpersonal
• Ce haut-parleur contient des circuits
haute tension présentant un danger.
Ne jamais essayer de le démonter. Il
durchgeführt werden.
ESPAÑOL
n’y a aucun composant qui puisse être • Para reducir el riesgo de descarga
• Do not allow water or any foreign
object to get inside the loudspeaker.
Do not put objects containing liquid
on, or near, the unit.
• To reduce the risk of overheating the
loudspeaker, avoid exposing it to
réparé par l’utilisateur. Toutes les
réparations doivent être effectuées
par du personnel qualifié et agréé par
le constructeur.
eléctrica, desconecte de la red el
altoparlante antes de instalar el cable
de señalización de interfaz de la seg-
nale. Vuelva a conectar el conductor
flexible de alimentación solamente
una vez efectuadas todas las inter-
conexiones de señalizatción.
DEUTSCH
direct sunlight. Do not install the unit • Um die Gefahr eines elektrischen
near heat-emitting appliances, such
as a room heater or stove.
Schlages auf ein Minimum zu
reduzieren, den Lautsprecher vom
Stromnetz trennen, bevor ggf. ein
Audio-Schnittstellensignalkabel
angeschlossen wird. Das Netzkabel
erst nach Herstellung aller
• Conecte el altoparlante a un tomacor-
riente bipolar y trifilar con neutro de
puesta a tierra. El tomacorriente debe
estar conectado a la protección de
derivación apropiada (ya sea un
fusible o un disyuntor). La conexión a
cualquier otro tipo de tomacorriente
puede constituir peligro de descarga
eléctrica y violar los códigos eléctri-
cos locales.
• No instale el altoparlante en lugares
donde haya agua o humedad excesiva.
• No deje que en el altoparlante entre
agua ni ningún objeto extraño. No
ponga objetos con líquidos encima de
la unidad ni cerca de ella.
• Para reducir el riesgo de sobrecalen-
tamiento, no exponga la unidad a los
rayos directos del sol ni la instale
cerca de artefactos que emiten calor,
como estufas o cocinas.
• Este altoparlante contiene niveles de
voltaje peligrosos en potencia. No
intente desarmar la unidad, pues no
contiene piezas que puedan ser repardas
por el usuario. Las reparaciones deben
efectuarse únicamente por parte del
personal de mantenimiento capacitado
en la fábrica.
• This loudspeaker contains potentially
hazardous voltages. Do not attempt
to disassemble the unit. The unit
contains no user-serviceable parts.
Repairs should be performed only by
factory-trained service personnel.
Signalverbindungen wieder einsteck-
en.
• Der Lautsprecher an eine geerdete
zweipolige Dreiphasen-Netzsteckdose
anschließen. Die Steckdose muß mit
einem geeigneten Abzweigschutz
(Sicherung oder Leistungsschalter)
verbunden sein. Der Anschluß der
unterbrechungsfreien Stromversorgung
an einen anderen Steckdosentyp kann
zu Stromschlägen führen und gegen
die örtlichen Vorschriften verstoßen.
• Der Lautsprecher nicht an einem Ort
aufstellen, an dem sie mit Wasser
oder übermäßig hoher
FRANÇAIS
• Pour réduire le risque d’électrocution,
débrancher la prise principale de
l’haut-parleur, avant d’installer le
câble d’interface allant à l’audio. Ne
rebrancher le bloc d’alimentation
qu’après avoir effectué toutes les con-
nections.
• Branchez l’haut-parleur dans une prise
de courant à 3 dérivations (deux
pôles et la terre). Cette prise doit être
munie d’une protection adéquate
(fusible ou coupe-circuit). Le
branchement dans tout autre genre de
prise pourrait entraîner un risque
d’électrocution et peut constituer une
infraction à la réglementation locale
concernant les installations élec-
triques.
Luftfeuchtigkeit in Berührung kom-
men könnte.
• Darauf achten, daß weder Wasser
noch Fremdkörper in das Innere den
Lautsprecher eindringen. Keine
Objekte, die Flüssigkeit enthalten, auf
oder neben die unterbrechungsfreie
Stromversorgung stellen.
• Ne pas installer l’haut-parleur dans un
3
USM-P: INTRODUCTION AND TECHNICAL ADVANTAGES
Thank you for investing in the Meyer
Sound USM-P Series. The USM-100P and
USM-1P self-powered stage monitors are
composed of:
horn's wider pattern (100°H x 40°V)
perceive this as a decrease to
half the SPL. When reading a
beamwidth specification, it is
essential to determine whether it
refers to the -6 or -10dB points
because they indicate very differ-
ent results: the -10dB points
yield a wider angle.
provides broad coverage in either wedge
or flown applications.
DESIGN BENEFITS:
• one 15-inch cone driver and one 3-
inch diaphragm compression driver;
• phase-corrected, optimized control
electronics;
• a two-channel amplifier
(350Wrms/ch).
• The amplifier is optimized for the sys-
tem, providing substantial power
without endangering the drivers.
• The integrated design simplifies setup
and installation, eliminates amp
racks, and extends the durability and
reliability of the loudspeaker.
• The gain structure between the con-
trol electronics and amplifier is per-
fectly matched.
Previous technologies produced horns
whose beamwidth varied over the oper-
ating frequency range. These horns also
displayed nonuniform frequency
response within, and significant side
lobe energy outside their beamwidth.
Both undesirable characteristics, partic-
ularly prevalent for horns with a wide
beamwidth, make array design extremely
problemactic.
Compared to conventional monitor
designs, Meyer Sound’s USM-P Series
loudspeakers are uniquely capable of
producing flat phase and amplitude
response, full bandwidth reproduction
and a near-perfect impulse response.
The USM-P boasts a maximum output of
132dB peak SPL at 1 meter with excep-
tionally low distortion and a noteable
lack of coloration at all amplitude lev-
els. An additional benefit of the design
engineering and system packaging of
the USM-P is its improved linearity and
lower susceptibility to feedback.
THE USM-P HORNS: CONSTANT-Q
Constant research and development
efforts at Meyer Sound have led to the
solution of the most difficult problems
associated with horn design. In order to
appreciate the significance of this work,
it is necessary to define an often misun-
derstood term: the beamwidth of a horn
is the angle at which the sound pressure
at a given frequency decreases to half
(-6dB) its on-axis amplitude. Specifying
beamwidth using the -6dB points has
been proposed as the audio industry
standard; Meyer Sound adheres to this
definition.
The USM-P was developed in Meyer
Sound's anechoic chamber by measuring
coverage patterns using angular and fre-
quency resolutions of 1° and 1/36
octave, respectively. The USM-P horns
exhibit Constant Q: the beamwidth
remains consistent across the horn's
operating frequency range in both the
vertical and horizontal planes.
USM-P Series systems excel in stage
monitoring applications that require
efficient response down to 30Hz for
clean, high level reproduction of bass
and drums. USM-P Series monitors can
be deployed as stage wedges or flown as
side-fill.
Both horns share the following remark-
able attributes:
• uniform frequency response within
the beamwidth
• rapid and uniform amplitude attenua-
tion for all frequencies outside the
beamwidth
NOTE: Unfortunately, beamwidth is often
used to describe the angle at
which the sound pressure
The USM-1P horn's narrow beamwidth
(45°H x 45°V) permits precise coverage
with minimal interaction between
neighboring monitors. The USM-100P
decreases 10dB from its on-axis
amplitude because many listeners • minimal side lobes
AC POWER
The USM-P uses a PowerCon locking 3-
pole AC mains connector that prevents
inadvertent disconnection. The unit
must have the correct power cord for
When AC power is applied to the USM-P,
an Intelligent ACtm supply automatically
selects the correct operating voltage,
allowing the USM-P to be used interna-
• filters EMI (radio frequencies and
noise present on the AC line)
• sustains operation during low-voltage
periods, which minimizes audio dis-
continuity
• provides soft-start power-up, which
eliminates high inrush current
the AC power in the area in which it will tionally without manually setting volt-
be used.
age switches. The Intelligent AC supply
performs the following protective func-
tions to compensate for hostile condi-
tions on the AC mains:
Engagement
Separation
1
The USM-P can withstand continuous
voltages up to 264V and allows any
combination of voltage to GND (i.e.
Neutral-Hot-GND, Hot-Hot-GND).
2
2
1
• suppresses high voltage transients up
to several kilovolts
3
4
Continuous voltages higher than amount at 115V; the inrush current at
an additional 30% above the minimum
amperage to prevent peak voltage drops
at the service entry and nuisance trip-
ping.
100V is 115% of the 115V amount.
264V may damage the unit.
!
The USM-P presents a dynamic load to
the AC mains which causes the amount
of current to fluctuate between quiet
and loud operating levels. Since differ-
ent types of cables and circuit breakers
heat up and trip at varying rates, it is
essential to understand the types of cur-
rent ratings and how they correspond to
circuit breaker and cable specifications.
VOLTAGE REQUIREMENTS
The USM-P operates safely and without
audio discontinuity if the AC voltage
stays within the range 88-264V, 47-
63Hz. After applying AC power, the sys-
tem is muted while the circuitry charges
up and stabilizes. After two seconds,
the On/Temp. LED on the user panel
illuminates green, the system unmutes
and is ready to pass audio signals. If
the On/Temp. LED does not illuminate
or the system does not respond to audio
input after ten seconds, consult the
Troubleshooting section.
POWER CONNECTOR WIRING
Use the following AC cable wiring dia-
gram to create international or special-
purpose power connectors:
brown = hot
blue =
neutral
yellow/green =
earth ground
(chassis)
The maximum continuous RMS current
is the maximum RMS current over a
duration of at least 10 seconds. It is
used to calculate the temperature
increase in cables, which is used to
select cables that conform to electrical
code standards. It is also used to select
the rating for slow-reacting thermal
breakers.
AC cable color code
If the colors referred to in the diagram
don't correspond to the terminals in
your plug, use the following guidelines:
The USM-P's power supply uses stored
energy to continue functioning for
about 10 AC cycles if the voltage
• Connect the blue wire to the terminal
marked with an N or colored black.
decreases below 88V (a condition known
as brownout). The precise length of time
the unit functions during brownout
depends on the operating level and how
low the voltage drops. The unit turns off
if the voltage does not increase above
88V before the storage circuits are
depleted. If the USM-P shuts down due
to brownout, the power supply automat-
ically turns on after three seconds if the
voltage returns to the normal operating
range. If the USM-P does not turn back
on after ten seconds, consult the
The maximum burst RMS current is the • Connect the brown wire to the termi-
nal marked with an L or colored red.
• Connect the green and yellow wire to
the terminal marked with an E (or )
or colored green (or green and yel-
low).
maximum RMS current over a one sec-
ond duration. It is used to select the
rating for most magnetic breakers.
The maximum instantaneous peak cur-
rent during burst is used to select the
rating for fast-reacting magnetic break-
ers and to calculate the peak voltage
drop in long AC cables according to the
formula below.
SAFETY ISSUES
Do not use a ground-lifting
adapter or cut the AC cable
ground pin.
Vpkdrop = Ipk x Rtotal cable
Troubleshooting section.
Keep all liquids away from the USM-P to
avoid hazards from electrical shock.
NOTE: We recommend that the supply be
operated at least a few volts
Use the table below as a guide to select
cables and circuit breakers with appro-
priate ratings for your operating
voltage.
Do not operate the unit with worn or
frayed cables; replace them immediately.
away from the upper and lower
bounds of the operating range to
avoid possible shutdown.
To determine the minimum total service
If the USM-P will be installed outdoors
contact Meyer Sound for information
about the rain hood and weather protec-
tion for the drivers and electronics.
CURRENT REQUIREMENTS
115V 230V 100V
Each USM-P requires approximately
3Arms @115V (1.5Arms@230V) for
proper operation. This allows up to five
USM-Ps to be powered from one 15A
breaker.
Idle RMS
Max. Continuous RMS 2.8A
Max. Burst RMS 3.2A 1.6A
Max Peak During Burst 5.0A 2.5A
.25A
.13A . 3A
1.4A
3.2A
3.7A
5.8A
While a single USM-P can be
hung by its handle bars and
!
fitted L-Track strips, do not
hang any additional weight
from the cabinet. USM-P han-
dle bars or the L-Track strips
mounted on the top front
panel are not designed to
support heavy rigging loads.
The maximum burst current of the
USM-P is equal to its maximum turn on
current. For example, a loud drumbeat
which draws 3A can be easily handled by
a 20A breaker powering five USM-1Ps.
power required by a system of USM-P, or
other Meyer self-powered speakers, add
their maximum continuous RMS cur-
The inrush current at 230V is 50% of the rents together. We recommend allowing
5
THE MODULAR REAR PANEL
The rear panel of the USM-P has two
slots for processor modules. The top slot loop, creating an unbuffered hardwired
contains the Audio Input and Control
Module; the bottom slot contains the
optional Remote Monitoring System™
(RMS) Module. A blank plate covers the
bottom slot if RMS is not installed. For
multiple USM-Ps with a paralleled input
in a positive pressure wave when a posi-
tive signal is applied to pin 2. With the
switch down (-), pin 3 is hot relative to
pin 2, resulting in a negative pressure
loop connection, with negligible loss in
signal level. For example, since the
input impedance of one USM-P is 10kΩ, wave when a positive signal is applied
looping 20 USM-Ps produces a balanced
input impedance of 500Ω. With a 150Ω
to pin 2. The level attenuator knob
operates between 0 dB (no level attenu-
ation) in a fully clockwise position to -
12 dB in a fully counter-clockwise posi-
tion.
drawings of these modules, see page 11. audio source, the 500Ω load results in
only a 2.28dB loss.
AUDIO INPUT
LOOPING AUDIO INPUT MODULE
There are three, interchangeable Audio
Input and Control Modules with opti-
mized connectors and controls for dif-
ferent applications. Each module has a
24V Fan connector to power an optional
fan (see page 11).
This standard module uses a balanced,
female XLR connector for audio input
and a male XLR loop connector to inter-
connect multiple speakers. The audio
input connector is hardwired with pin 2
hot to comply with audio industry stan-
dards. The loop connector, wired in par-
allel to the audio input, transmits the
input signal if the USM-P is turned off
for any reason.
REMOTE MONITORING SYSTEM
The USM-P can be equipped to operate
with the Remote Monitoring System
(RMS) network and software application.
RMS displays signal and power levels,
driver and cooling fan status, limiter
activity, the state of the polarity switch,
attenuator level, and amplifier tempera-
ture for all speakers in the network on a
Windows-based PC. RMS is an excellent
field-diagnostic tool that removes the
guesswork from troubleshooting during
a performance. All Meyer RMS-compati-
ble speakers use the same RMS module
(depicted on page 11) so they can be
Each module uses a three-pin, female
XLR audio input connector with a 10kΩ
balanced input impedance wired with
the following convention:
Pin 1 -220 kΩ to chassis and earth
ground (ESD clamped)
LOOPING, POLARITY, AND ATTENUATING
AUDIO INPUT MODULE
Pin 2 -Signal
Pin 3 -Signal
Case
-Earth (AC) ground and
chassis
This module has a balanced, female XLR
audio input connector, a male XLR loop
Pins 2 and 3 carry the input as a differ-
ential signal. Use standard audio cables
with XLR connectors for balanced signal
sources. A single audio source can drive
connector, an input polarity switch, and easily exchanged between speakers .
a level attenuator knob. With the input
polarity switch in the up (+) position,
pin 2 is hot relative to pin 3, resulting
Installing an RMS module requires only
a Phillips screwdriver. Contact Meyer
Sound for more information about RMS.
AMPLIFICATION, LIMITING, AND COOLING SYSTEM
AMPLIFICATION AND LIMITING
panel (the high limit is above the low
limit LED).
While the USM-P limiters fully protect
the system under overload conditions
and exhibits smooth sonic characteris-
tics, we recommend that you do not
intentionally drive the USM-P into con-
tinuous limiting to attain compression
effects.
Each driver in the USM-P is powered by
one channel of a proprietary Meyer
The USM-P performs within its acoustical
specifications and operates at a normal
temperature if the limit LEDs are on for
no longer than two seconds, and off for
at least one second. If either LED
remains on for longer than three sec-
onds, that channel incurs these negative
consequences:
Sound amplifier utilizing complementary
power MOSFET output stages (class AB,
bridged, 350Wrms/ch). Each channel has
a limiter that prevents driver over-excur-
sion and regulates the temperature of
the voice coil. The limiters protect the
drivers without the glaring compression
effects imposed by typical limiters,
For applications where large amounts of
compression are required, we recommend
using an outboard compressor/limiter
for greater control of limit and compres-
sor effects.
allowing high SPLs across each driver's
entire frequency range. Limiter activity
for the high and low channels is indicat-
ed by two yellow Limit LEDs on the rear
• Increasing the input level will not
increase the volume.
• The system distorts due to clipping
and nonlinear driver operation.
6
es to 75°C (167°F), the On/Temp. LED
changes from red to green and the lim-
iter threshold returns to normal.
fan, powered by the 24V Fan user panel
connector, blows air directly onto the
heatsink. The fan speed increases as the
heatsink temperature rises, which main-
tains a safe operating temperature with
minimal fan noise. Contact Meyer Sound
to order the fan kit.
AMPLIFIER NATURAL CONVECTION
COOLING SYSTEM
The USM-P employs a natural convection
cooling system that depends on air flow
from below the cabinet over the
The heatsink gets too hot to
touch during normal opera-
tion. Use extreme caution
heatsink. Allow for proper ventillation
of fresh air when using the speaker.
!
near the rear of the cabinet.
POWER SUPPLY FAN
If the temperature of the heatsink
The power supply is cooled by a single small
internal fan that turns on low when the unit
is first powered up. The fan doubles its speed
as the system is driven with audio. Since the
fan draws air in from, and exhausts it out the
side of the cabinet, there must be at least six
inches on the amplifier's side of the cabinet
and adequate air flow.
FAN ASSEMBLY KIT
reaches 85°C (185°F), the On/Temp.
LED on the rear panel turns from green
(On) to red (Temp.) and the limiter
threshold is lowered to a safe level to
prevent the amplifiers from overheating.
Under high temperature conditions the
limiter threshold is reduced to 6 dB.
When the heatsink tmeperature decreas-
While convection cooling is adequate
for most applications, driving the USM-
P into frequent limiting under severe
temperature conditions, or where venti-
lation is restricted, an optional fan kit
is available to maintain a safe operat-
ing temperature. The easy-to-install
COVERAGE
The Constant Q design of the horn allows The USM-1P's coverage area is:
frequencies outside of the coverage area
of the speaker to attenuate quickly. This
is excellent for monitoring where several
different monitors are used in close
proximity. When placing the monitor
carefully consider the coverage pattern
of the USM-P and USM-100P.
-6 dB points: 45° H x 45° V
-10 dB points: 65° H x 65° V
The USM-100P's coverage area is:
-6 dB points: 100° H x 40° V
-10 dB points: 120° H x 60° V
The following drawings illustrate the coverage area of each horn from three different
perspectives in order to depict the three dimensional coverage pattern.
USM-100P (Top View)
USM-1P (Front View)
USM-1P (Side View)
USM-1P (Top View)
USM-1P (Top View)
USM-100P (Side View)
7
VERIFYING POLARITY
Incorrect driver polarity impairs system
performance and may damage the dri-
vers. All Meyer Sound loudspeakers are
shipped with the drivers in correct
alignment.
4. Apply the same signal to the second
speaker with the first speaker still
connected.
DRIVER POLARITY IN THE SAME USM-P
Use the following test procedure to veri-
fy polarity between drivers in the same
loudspeaker:
The polarity is correct if the frequency
response remains constant with a 5-6dB
SPL increase in amplitude. Broadband
cancellation (decreased overall level)
indicates polarity reversal.
1. Place a monitoring microphone 1
meter from the front of the loud-
speaker at the midway point between
the high and low frequency drivers.
2. Connect a full range signal to the
loudspeaker and note the frequency
response.
If the driver or circuit wiring has been
removed or disassembled it is essential
to check the polarity between adjacent
monitors and between drivers and
between adjacent loudspeakers.
Since polarity reversal causes
excessive driver excursion at
high source levels, use mod-
erate levels when conducting
these tests.
!
POLARITY IN ADJACENT LOUDSPEAKERS
Use the following test procedure to veri-
fy the polarity between two adjacent
loudspeakers of the same type:
The polarity is correct if the frequency
response is smooth through the
crossover region (800Hz to 1.5kHz).
Cancellation of 6dB or more in this
region indicates polarity reversal.
1. Position two loudspeakers adjacent to
each other.
USM-P
Reference
2. Place a measurement microphone 3ft.
from the speakers and 3 to 4 feet
above the USM-1Ps, on the axis
between the speakers.
3. Connect a signal source to one speak-
er and note the frequency response
and overall level.
3 Feet
USM-P
Under Test
TROUBLESHOOTING
This section suggests several possible
solutions to some common problems
encountered by USM-P users and is not
intended to be a thorough troubleshoot-
ing guide.
correct type for the regional voltage
and that it is securely connected to
the AC inlet then unplug and recon-
nect the AC cable.
5. If possible, monitor the audio source
with headphones.
HUM OR NOISE IS PRODUCED BY THE
SPEAKER.
1. Disconnect the audio input. If the
hum ceases, the noise originates
somwhere earlier in the signal path.
If the noise persists, the problem is
within the USM-P.
2. Make sure the XLR cable is securely
fastened to the XLR audio input con-
nector.
3. Send the audio signal to another
speaker to insure signal presence and
that the level is within the proper
range. Turn the source level down
before reconnecting the audio input
and increase the level slowly to avoid
a sudden blast of sound.
2. Use an AC voltmeter to verify that
the AC voltage is within the ranges
88-264V, 47-63 Hz.
Qualified electronics technicians with
access to a test bench can request the
following documents from Meyer Sound:
Troubleshooting Guide, The Low
Frequency Driver Replacement
Procedure, and The High Frequency
Driver Replacement Procedure for the
USM-1P/100P.
THE ON/TEMP. LED IS ILLUMINATED
BUT THERE IS NO SOUND.
1. Verify that the audio source (mixer,
EQ, delay) is sending a valid signal.
2. Make sure the XLR cable is securely
fastened to the XLR audio input con-
nector.
3. Verify that the XLR cable is function-
ing by substituting another cable or
by using the cable in question in a
working system.
4. Send the audio signal to another
speaker to insure signal presence and
that the level is within the proper
range. Turn the source level down
before reconnecting the audio input
and increase the level slowly to avoid
a sudden blast of sound.
If your difficulty persists, or if you sus-
pect the problem lies solely within the
USM-P, please contact Meyer Sound
Technical Support or return the unit to
the factory or nearest authorized service
center.
5. Hum or noise can be produced by a
ground loop. Since the USM-P is
effectively ground-lifted, this should
not occur unless grounds are extreme-
ly different voltages.
THE ON/TEMP. LED DOES NOT ILLUMI-
NATE, THERE IS NO AUDIO, AND THE
POWER SUPPLY FAN IS OFF.
1. Make sure the AC power cable is the
8
with high-quality headphones.
2. Send the audio signal to another
speaker to insure that the signal is
full-range. Turn the source level down
before reconnecting the audio input
and increase the level slowly to avoid and Cooling System on page 6 for a
a sudden blast of sound.
3. Use a sine wave and/or pink noise
generator to send a variety of fre-
quencies to the speaker.
than 30°C and this condition occurs
frequently, contact Meyer Sound to
order the optional Fan Kit.
THE AUDIO PRODUCED BY THE SPEAKER
IS DISTORTED OR COMPRESSED BUT THE
LIMIT LIGHT IS NOT ILLUMINATED.
1. Make sure the XLR cable is securely
fastened to the XLR audio input con-
nector.
2. Send the audio signal to another
speaker to insure that the level is
within the proper range. Turn the
source level down before reconnect-
ing the audio input and increase the
level slowly to avoid a sudden blast
of sound.
See the section Amplification, Limiting,
complete discussion about the cooling
system.
THERE IS NO SOUND, THE ON/TEMP.
LED IS DIM OR OFF, AND THE POWER
SUPPLY FAN IS ON HIGH SPEED.
This extremely rare event occurs when
the power supply overheats, causing a
1-2 minute interruption in operation.
The unit turns on again when the power
supply has cooled sufficiently.
THERE IS SOME SOUND BUT THE
ON/TEMP. LED TURNS FROM GREEN TO
RED.
This occurs when the heatsink tempera-
ture reaches 85°C (185°F), indicating
that the amplifier is thermally over-
loaded. The limiter threshold has
dropped to a safe level, so the audio
level is probably reduced.
3. Monitor the audio source with head-
phones.
THE AUDIO PRODUCED BY THE SPEAKER
IS HIGHLY COMPRESSED AND THE LIMIT
LIGHT IS CONSTANTLY YELLOW.
1. Turn down the level of the input sig-
nal to the speaker system.
1. Make sure there is at least six inches
clearance behind the unit.
2. Make sure there is sufficient air flow
around the unit.
3. Avoid exposing the unit to direct
sunlight in high ambient temperature.
1. Make sure there is enough clearance
above, below, and behind the unit.
2. Make sure there is sufficient air flow
around the unit.
ONLY THE HIGH OR LOW DRIVER SEEMS
TO PRODUCE SOUND.
1. Make sure the audio signal is full-
range and has not been filtered in a
previous stage of the signal chain. If
possible, monitor the audio source
3. Avoid exposing the heatsink to direct See the section Amplification, Limiting,
sunlight if the ambient temperature
and Cooling System on page 6 for a
more information about the power sup-
ply's internal fan and cooling system.
is high.
4. If the ambient temperature is greater
9
USM-1P/100-P SPECIFICATIONS
Operating Frequency Range2 30 Hz - 20 kHz
Acoustical1
(each loudspeaker)
Free Field 44 Hz - 16 kHz 3 dB; -6 dB at 40 Hz and 20 kHz
Half-Space3 40 Hz - 16 kHz 3 dB; -6 dB at 33 Hz and 20 kHz
Phase Response4
35° 500 Hz - 16 kHz; +90° at 120 Hz
Maximum Peak SPL5 132 dB
Signal to Noise Ratio >95 dB (A-weighted noise floor to max SPL)
USM-100P -6 db at 100° H x 40° V; -10 dB at 120° H x 60° V
USM-1P -6 db at 45° H x 45° V; -10 dB at 60° H x 60° V
Coverage
Crossover
USM-100P 900 Hz
USM-1P 1000 Hz
Low Frequency 15-inch cone driver
Transducers
High Frequency 3-inch diaphragm compression driver
Type Differential balanced input circuit
Connector Female XLR; Male XLR Loop
Standard Audio
Input Module
Impedance 10 kΩ differential (between pins 2 and 3)
XLR Wiring Pin 1: chassis; Pin 2: + signal; Pin 3: - signal
RF Filter Common Mode: 425 kHz low-pass;
Differential Mode: 142 kHz low-pass
Common Mode Rejection Ratio >80 dB (50 Hz - 1 kHz); typically 90 dB
Type Complementary power MOSFET output stages, class AB/bridged
Output Power 350 Wrms/channel
THD, IM, TIM < .02 %
Amplifiers
AC Power
Connector PowerCon locking AC connector
Automatic voltage selection 88 - 264 VAC continuous; 47 - 63 Hz
Idle RMS Current 115 V: 0.25 Arms
Max Continuous RMS Current (>10 s) 115 V: 2.8 Arms
Max Burst RMS Current (<1 s) 115 V: 3.2 Arms
Max Peak Current During Burst 115 V: 5.0 Apk
230 V: 0.13 Arms
230 V: 1.4 Arms
230 V: 1.6 Arms
230 V: 2.5 Apk
100 V: 0.3 Arms
100 V: 3.2 Arms
100 V: 3.7 Arms
100 V: 5.8 Apk
Soft Start Turn-on Inrush current <15 A @115 V
Dimensions Height: 16.9” (429mm) ; Width: 16.5” (419mm); Length: 22.4”
Physical
(569mm); Depth (w/grill) 15.19” (386mm)
Weight 88 lbs (40 kg)
5
Enclosure/Finish
/ ” birch plywood/black textured
8
Protective Grill Removable perforated steel grill, charcoal grey foam
1
Notes
1. Measurements are taken at 3 m on-axis, /3 octave, unless otherwise stated.
2. Response depends on loading conditions and room acoustics.
3. Measured at 1.5 m with the USM-1P/100-P on a single boundary.
4. Phase variation from pure delay.
5. Measured at 1 m, with pink noise or music.
Meyer Sound reserves the right to alter any specification with-
for up-to-date information.
© 2000 Meyer Sound
Laboratories, Inc.
All rights reserved
10
USER PANEL AND OPTIONAL MODULES
The user panel and optional module are described on page 6 of this document.
User Panel with RMS option and Polarity and Attenuaing Audio Input Module
Looping, Polarity, and Attenuaing Input Module
11
PHYSICAL DIMENSIONS
All units in inches.
USM-1P
USM-100P
CONTACT INFORMATION
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
tel: 510.486.1166
fax: 510.486.8356
e-mail: [email protected]
05.089.004.01 Rev A
12
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