Low Impedance Indicator
AM II circuitry will lower output power to maintain uninterrupted operation whenever the
amplifiers enses an impedanceload of less than 2 Ohms. The Low Impedance Indicator
(left-side end panel) is provided to let you know when the amplifieris operating in this
mode. It is importantto note that there is no increase in output power below the 2 Ohm
threshold. Maximumpower is achieved at 2 Ohms.
In the case of a short circuit, AM II will engage to protect the shorted channel but will
continue to play the unaffected channel. When this occurs, audible distortion will be
heard. Turn-off the system and repairthe short. Once the problem has been repaired,
the amplifierwill return to normal operation.
System Tuning
In order to achieve maximumsignal-to-noise performance from a high quality mobile
sound system,it is desirable to use high signal levels wherever possible in the
interconnection cables. High signal levels will reduce the effect of induced noise. The
peak level of an audio signal is usually determined by the clipping level of electronic
components.The following procedure s hould be used as a guide whenthe s ystem
installation is complete.
AdjustingEqualizer Input Gains:
1. Turn the equalizer's volume control to minimum.
2. Turn the source unit volume 1/2 to 3/4 of maximum. If available on your unit, set
the output level to maximum.Some units may have a switch.
3. If available, set selector switch to either input 1 or input 2.
4. Adjust all equalizer input gains to minimum.
5. For the chosen input play the respective music source. A loud music passage
is desired.
6. For the chosen input, increase the left input gain control until the onset of audible
distortion. Then decrease the gain prior to the immediatepoint of audible
distortion. This setting will minimizesystem background noise and prevents
overloading of the equalizer. Adjust, for the sameinput, the right input gain
control for proper left / right balance.
7. Set selector switch to the alternative source unit, if used, and repeat steps 5 and
6.
8. Adjust crossover next.

Adjusting Crossover Input Gains:

1. Adjust all crossover gain controls to 0 dB, 1/2 of maximumsensitivity.
2. Adjust all amplifiergains to 1/2 of maximum sensitivity.
3. Turn the volume knob on the equalizer to a maximumof 3 o'clock.
4. Increase the gain of the crossover until the onset of audible distortion. Then
decrease the gain prior to the immediatepoint of audible distortion. This setting
will minimizesystem background noise and prevents overloading of the
crossover.
5. Repeat step 4 for any remaining crossovers in the system.
6. Adjust the input gains next.

Adjusting the Amplifier's input Gain:

NOTE: In manu multi-crossover / accessory systems, the gain of some
crossover and accessories may need to be further decreased to achieve
proper balance.
1.
2.
3.
4.
Adjust the amplifier's input gain to 1/2 maximum sensitivity
Turn the volume knob on the equalizer to a maximum of 3 o'clock
Increase the gain (clockwise) until the onset of audible distortion. Then
decrease the gain counterclockwise prior to the immediate point of audible
distortion. Thissetting will minimize system background noise and prevents
overloading of the amplifier.
Repeat step 3 for any remaining amplifiers in the system.
NOTE: Depending on the sensitivity of the system's preamp(s), the gain of
the amplifier(s) may not need adjustments. Also, in many multi-amplifier
systems, the gain of some amplifiers may need to be further decreased to
achieve proper balance.