Meyer Sound UPA-2C - Manual (Page 3)

Power 120/240V AC, 50/60 Hz (internally switchable)
Physical Dimensions 19" W x 1 3 ⁄
4
" H x 7 3 ⁄
4
" D Standard rack mount
Weight 8 lbs. (3.6 kg)
The UPA-2C loudspeaker operates as a system with
the M-1A Control Electronics Unit (one per channel).
Optimized for the UPA series and pre-aligned at the
factory, the M-1A contains frequency response and
phase response alignment circuitry, and Meyer Sound's
exclusive SpeakerSense
™ driver protection circuitry,
incorporating both peak and RMS signal limiting.
A single-channel device operating at line level, the
M-1A is intended to be the final component in the signal
chain before the power amplifier. Its factory-calibrated
SpeakerSense circuitry protects the UPA-2C loudspeaker
components from damage due to overheating under
high power conditions. This unique circuit continuously
monitors the power applied to the UPA-2C drivers, and
individually limits the high-frequency and low-fre-
quency outputs when the safe operating limits of the
drivers are exceeded. Until the onset of overload, the
SpeakerSense circuitry has no effect on the signal.
Also provided is a switch-selectable Safe function,
which widens the safety margin of the system and is
intended to be used when extended periods of overload
are anticipated. The Safe switch and other setup controls
are located behind a cover plate on the M-1A front panel,
providing a means of securing the system installer's
presets.
To enhance the effectiveness of the UPA-2C, the M-1A
incorporates sliding filters which band-limit the system
response under full-power conditions. This has the effect
of discriminating for vocal information in the signal to
increase clarity, and is particularly useful when sound
pressure levels are high. It is recommended that subwoof-
ers be used with the system if it must pass the full audio
frequency range at all times. The preferred choice of
subwoofer for the UPA-2C is the Meyer Sound USW-1.
M-1A Control Electronics Unit
UltraSeries™ M-1A
Power
Sense Limit
Safe
Adj
Lo Cut
Cal
VHF
Var
Safe ∞
20
10
8 4
3
2
1
0
Attn dB
5 6
+ -
Lo
Hi
VHF