The S-1 ControlElectronics Unit
The MSL-2A operates as a system with
the S-1 Control Electronics Unit (one per
channel). A single-channel device operating
at line level, the S-1 is the final component
in the signal chain before the amplifier.
Optimized for the MSL-2A loudspeaker
and pre-aligned at the factory, the S-1
contains frequency and phase response
alignment circuitry, and Meyer Sound’s
exclusive SpeakerSense
™
driver protection
circuitry, incorporating both peak and RMS
signal limiting as well as excursion protec-
tion.
SpeakerSense driver protection circuitry
protects the MSL-2A loudspeaker compo-
nents from damage due to overheating or
excessive excursion under high power con-
ditions. This unique circuit continuously
monitors the power applied to the MSL-2A
drivers, and individually limits the high-
frequency and low-frequency 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.
The S-1 SpeakerSense circuit incorpo-
rates Meyer Sound’s new MultiSense™
function, which allows the use of multiple
power amplifiers having different channel
gains and/or power ratings. The S-1 accom-
modates two stereo power amplifiers, and
provides separate Sense inputs for each. Its
MultiSense circuit, which implements an
analog OR condition, automatically tracks
the power amplifier with the greatest out-
put voltage swing to control the system
protection limiters.
To enhance the effectiveness of the
MSL-2A in stage monitoring applications,
the S-1 incorporates sliding filters which
band-limit the system response under full-
power conditions. This has the effect of dis-
criminating for vocal information in the
signal to increase clarity.
Also provided is a switch-selectable Safe-
guard function, which widens the safety
margin of the system and is intended to be
used when extended periods of overload are
anticipated. The Safeguard switch and
other setup controls are located behind a
cover plate on the S-1 front panel, provid-
ing a means of securing the system
installer’s presets.
UltraSeries™ S-1
Power
Sense Limit
Safe
Adj
Lo Cut
Cal
VHF
Var
Safe
∞
20
10 843
2
1
0
Attn dB
5
6
-
Lo
Hi
VHF