Meyer Sound UPA-1P - Manual (Page 6)

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Looping Audio Input Module
This standard module uses a balanced, female XLR con-
nector for audio input and a male XLR loop connector to
interconnect multiple speakers. The audio input con-
nector is hardwired with pin 2 hot to comply with audio
industry standards. The loop connector, wired in parallel
to the audio input, transmits the input signal if the UPA-
P is turned off for any reason.
Summing Audio Input Module
This module has two balanced female XLR connectors.
The second female XLR connector functions as a summing
input. Applying a signal to one of the inputs results in a
normal signal level. Utilizing both summing inputs cre-
ates a correctly summed mono signal with each input 6
dB below the level of a single input. This is an effective
method for distributing both sides of a stereo signal to a
single UPA-P without requiring external level control.
Looping, Polarity, and Attenuating Audio
Input Module
This module has a balanced, female XLR audio input
connector, a male XLR loop connector, an input polarity
switch, and a level attenuator knob. The input polarity
switch offers a convenient method of reversing the phase
of the speaker. When the input polarity switch is in the
up (+) position, pin 2 is hot relative to pin 3, resulting
in a positive pressure wave when a positive signal is
applied to pin 2. When the switch is down (-), pin 3 is hot
relative to pin 2, resulting in a positive pressure wave
when a positive signal is applied to pin 3. The level
attenuator knob operates between 0 dB (no level attenu-
ation) in a fully clockwise position to –12 dB in a fully
counterclockwise position.
Remote Monitoring System
    
The UPA-P can be equipped to operate with the Remote
Monitoring System
(RMS) network and software appli-
cation. 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 can also be configured to enable speaker mut-
ing. RMS is an excellent field-diagnostic tool that re-
moves the guesswork from troubleshooting during a per-
formance. All Meyer loudspeakers with RMS can be inte-
grated on the same network. 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
Each driver in the UPA-P is powered by one channel of a
proprietary Meyer Sound amplifier utilizing complemen-
tary power MOSFET output stages (class AB, bridged,
350 Wrms/ch). Each channel has a limiter that prevents
driver over-excursion and regulates the temperature of
the voice coil. The limiters protect the drivers without the
glaring compression effects imposed by typical limiters,
allowing high SPLs across each driver’s entire frequency
range. Limiter activity for the high and low channels is
indicated by two yellow Limit LEDs on the rear panel
(the High Limit LED is above the Low Limit LED).
The UPA-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
seconds, that channel incurs these consequences:
• Increasing the input level will not increase the
volume.
• The system distorts due to clipping and nonlinear
driver operation.
• Unequal limiting between the low and high fre-
quency drivers alters the frequency response.
While the UPA-P limiters fully protect the system under
overload conditions and exhibit smooth sonic charac-
teristics; we recommend that you do not intentionally
drive the UPA-P into continuous limiting to attain com-
pression effects.
For applications where large amounts of compression
are required, we recommend using an outboard compres-
sor/limiter for greater control of limit and compressor
effects.
Amplifier Natural Convection Cooling System
The UPA-P’s amplifier employs a natural convection cool-
ing system that is cooled by the air flowing over the
heatsink.
Allow for proper ventilation of fresh air when
using the speaker in tightly packed conditions.
If the temperature of the heatsink 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