Ashly Electronic Amplifier none - Manual (Page 7)

In a typical setup, power amplifiers can be run "full-on", with level control
being accomplished at the crossover. Adjust these controls for best system
balance. Note that horn and compression driver combinations are much more
efficient than cone speakers, often by 12-20dB. When cones and compression
drivers are used together, you should expect a much lower level setting for
the horns (all other factors being equal) to compensate for this difference
and obtain proper balance.
PEAK LED
Ashly crossovers feature a peak detection circuit which monitors signal levels
at several critical points in the crossover: input, filters, and outputs. The
LED will flash when signal levels of +14dBV are reached anywhere in the
crossover. Since our crossovers have a nominal 20dB of headroom referenced to
a standard operating level of OdBY (.77 Volts), a flashing LED warns you that
you are only 6dB away from clipping.
Choice of a "nominal" system operating level is really up to the operator.
You may want to run the system "hot", with the peak LED flashing frequently,
or you may want to run the system more conservatively, with the LED flashing
seldom or never.
Obviously, the hotter your nominal level, the less system headroom you will
have. For initial setup, it is recommended that you adjust your level
controls so that the LED flashes only on the loudest signal peaks, if at all.
Since peak levels are monitored at several key circuit points, the peak LED
can be used to isolate the source of any overload. If the LED flashes even
though all input and output levels are turned down, then the signal being fed
to the crossover is excessively hot. In most cases this means you should go
back and turn down your mixer. If the LED flashes when you turn the Input
level
control up (with the outputs still turned down), the overload is
occurring in the filter sections, and you should back the Input level down a
bit. If the LED first flashes when you turn the output level controls up,
then the overload is occurring in the output stage, and you need to turn the
output controls down.
OUTPUT LEVEL CONTROLS
Output
Level
Controls
Crossover
Frequency
Controls^
Peak
Input
Level
Rolloff
Figure 2 An SC-70 3-way crossover, showing front panel controls
generic to all Ashly crossovers.