Meyer Sound Control Electronics Unit S-1 - Manual (Page 2)

Operating Instructions
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
S-1
Control
Electronics
Unit
Operation Once all the connections have been made and verified,
the system is ready to operate.
• The S-1 Attn dB level control should be set at mini-
mum.
• Switch on the AC power to the S-1 first, then to the
power amplifier.
• Set the power amplifier level controls (If any) to maxi-
mum.
• Advance the S-1 Attn dB level control to set the
system sensitivity. If the system is not operating
properly, recheck all connections.
Note. The Attn dB level control markings are merely a
visual aid and should not be used to balance two sys-
tems. The output of the S-1 is calibrated only when the
level control is fully clockwise.
Preset Panel
Controls The setup controls on the S-1 Preset Panel are designed
to be used to tailor the system response for particular
applications. Remove the Preset Panel cover plate to
adjust the controls.
Safe Switch. The S-1 incorporates three limiters in the
SpeakerSense driver protection circuitry (see detailed
description, below). When the Safe switch is engaged the
RMS limiters come on at 6 dB lower power levels, afford-
ing added protection when heavy continuous power
demands are placed on the system (the VHF peak limiter
threshold is unaffected). For operator convenience, a
green LED indicator is provided on the S-1 front panel
and when the Safe switch is engaged, this indicator will
light. Note: It is recommended that the Safe switch be
engaged until the operator is familiar with the system’s
capabilities.
VHF Switch and Control. The VHF Switch affects the
very high frequency response of the system. It selects
either a preset (CAL) high frequency response or vari-
able response (VAR). In the VAR position, system re-
sponse around 16 kHz is adjustable (3/4 turn screwdriver
adjustment) from +3 dB to -3 dB around the preset point
(CW for increased level at 16 kHz). This feature may be
used to emphasize or de-emphasize sibilants, compen-
sate for room acoustics, etc.
Lo Cut Switch. This switch introduces a 6 dB/octave
high pass filter at 160 Hz. It is designed to provide an
alternative crossover slope when using Meyer Sound
subwoofers, and can also be used to compensate for the
proximity effect of cardioid microphones. For additional
information, see Use with Meyer Sound Subwoofers.
SpeakerSense™
Driver Protection Through the Sense connections back to the S-1 from the
power amplifier, the SpeakerSense circuitry of the S-1
continuously monitors the voltage across both the high
and low frequency drivers. If the amplifier output exceeds
the safe operating limits of the drivers, independent high-
and low-frequency limiters are automatically activated,
holding down the power level of the S-1 outputs.
The operation of the SpeakerSense circuitry is indicated
by a set of five LEDs located on the front panel.
Sense indicators. These function as signal presence
indicators, and verify that the Sense connections to the
S-1 are made. These indicators will be lit whenever a
signal is present, or will flicker at low signal levels.
Limit Indicators. These indicators will come on when-
ever the corresponding limiter is activated, and a moder-
ate amount of flashing of these indicators is acceptable.
The HF and LF limiters have an attack time of 100 msec
so they will not affect peaks in the program material, nor
will they prevent momentary amplifier clipping on peaks.