Infinity MODULUS Owner's Manual page 4

5
7 a Pass
INPUT OUTPUT
——+ tf —— .
+ = +
+ e 2 +
° 1 —
ALL CAPACITORS = 0.022 uF DIP SWITCHES.
TYPICAL, ONE CHANNEL SHOWN
Figure 5. High Pass Filter Schematic Diagram
*NOTE: When plugged into the second pair of high pass outputs, the shunt
resistor is in parallel with the input of the satellite amplifier. This lowers the
effective impedance, allowing the use of the built-in capacitors in the ECU. It
the amplifier you are using for your satellites requires the use of shunt resistors,
as shown by the table above, call or write Infinity's Customer Service Depart-
ment for assistance.
The 140Hz crossover frequency is not critical, and is given as a starting
point. If, for example, your satellite speaker power amplifier has an input
impedance of 200K, which requires a 68K shunt resistor to achieve the 140Hz
crossover frequency, you could set the DIP switches for a 120K input im-
pedance, and play the system without the 68K shunt resistor. This will result
in a lower than 140Hz crossover frequency. If your satellite speakers show
signs of distress (distortion) in the lower frequencies, exercise caution on how
loudly you play the system until you can install the correct shunt resistor.
Changing the Subwoofer Input Voltage Setting and Fuse
1. Inthe center of the A.C. VOLTAGE SELECTOR, loosen the fuse holder
with a 1/4 turn counterclockwise.
2. Using a pair of needle-nose pliers, insert the tips in the indentations,
near the 110 and 200 marks, and slowly turn the switch to the desired setting.
3. Remove the fuse and verify the size. NEVER INSTALL A FUSE WITH
A HIGHER THAN RECOMMENDED RATING.
4. Install the fuse by pushing in and turning clockwise until it locks in place.
Connecting the Subwoofer and ECU
CAUTION: Make sure that the voltage settings are the same for the
ECU and Subwoofer.
1. On your audio system, locate the cable connected between the
PREAMPLIFIER OUTPUT and AMPLIFIER INPUT.
2. Unplug the cable from the AMPLIFIER INPUT.
3. Refer to figure 6 and connect the PREAMPLIFIER OUTPUT to one of
the ECU INPUT pairs.
4. Connect a cable between one of the ECU HIGH PASS OUTPUT pairs
and your satellite speaker amplifier's INPUT.
5. Connect the supplied 25 foot cable between the ECU OUTPUT con-
nector and the subwoofer input panel INPUT connector.
PREAMP
OUTPUTS.
Loser
ECU AMPLIFIER,
SUBWOOFER
SPEAKERS
Figure 6. System Interconnecting Diagram
Positioning the Subwoofer
The performance of the subwoofer with your satellite speakers is directly
related to where it is placed in the listening room and how it is positioned with
tespect to the satellite speakers. The final position will be the result of patience
and experimentation on your part. Testing for sonic balance and blending
should always be done from your normal listening position using a wide range
of source material.
Starting Position
Begin your position experimentation by placing the subwoofer closer to the
right satellite speaker with the rear of the subwoofer approximately six or seven
inches from the rear wall, as shown in figure 7.
The initial position may turn out to be the most satisfactory. However, it is
recommended that other locations be tried to obtain a smooth transition
between the bass frequencies and the rest of the musical range. Figure 8
shows how bass response is affected by the subwoofer's position with respect
to the wall(s). If the bass response is lean, try Jocating the subwoofer closer
to a wall. If thebass is too heavy, the subwoofer should be moved away from
the wall and placed near the center of the two satellite speakers. It is
acceptable to place the subwoofer anywhere it looks and sounds best.