Infinity MODULUS Owner's Manual page 3

INPUT jacks (parallel pair) — one pair is used to connect the preamp output
to the ECU. If you want to bypass the ECU's internal highpass crossover,
the second pair can be used to connect the preamp output directly to the
satellite speaker's amplifier.
HIGH PASS OUTPUT jacks (parallel pair) — one pair is used to connect
the high pass output to the satellite speaker's amplifier. The second pair
can be used to connect an RCA-type shunt resistor when required. This is
discussed later in this manual.
A.C, VOLTAGE SELBCTOR - sets the ECU's power supply to conform
with the A.C. line voltage at the user's location. The ECU is normally
shipped with this switch set to 110 volts.
HOH fags FREQUENCY
err RIGHT
125458 123456
Figure 3. ECU Input/Output Panel
MAKING YOUR SUBWOOFER READY FOR USE
Installing the Isolation Feet
The four (4) black-metal isolation feet must be installed on the bottom panel
of the enclosure. To install the isolation feet:
1. Place the subwoofer on a soft, clean, scratch-free surface with the
bottom facing up.
2. Remove the plugs (figure 4) in each of the isolation feet mounting holes.
3. Screw one isolation foot in each of the pre-threaded holes. Make sure
that the isolation feet are tight.
Figure 4. Isolation Feet Installation
Installing The Isolation Feet Covers
If the subwoofer is going to be placed on a hardwood or tile surface, we
recommend that you install the plastic covers over the isotation feet. The
covers will prevent the féet from scratching the floor surface.
The covers should be glued in place with a small dab of the supplied silicone
adhesive.
Input Voitage Settings
CAUTION: Before making any connections between the subwoofer,
ECU, and your audio system components, be sure that the power
switches are off and thé'A.C. plugs are removed from the wail outlet.
The ECU and subwoofer are designed to operate from a variety of input
voltage levels and frequencies. When the voltage is changed, the current rating
of the input fuse may also change.
The ECU contains an internal fuse that offers protection at all of the voltage
settings.
The subwoofer input fuse must be changed per the following list as the
input voltage level is changed.
The voltages are set using the A.C. VOLTAGE SELECTOR on the ECU
input/output panel and the A.C. VOLTAGE SELECTOR on the subwoofer
input panel.
The following is a list of the available voltage settings and applicable fuse
size (current rating) for each.
Vol Fri Euse Size
120V/60Hz (US) 6 amp siow-blow
100V 50/60Hz 6 amp slow-blow
220V/50Hz 3 amp slow-biow
240V/50 Hz 3 amp slow-blow
Changing the ECU Input Voltage Setting
The ECU input voltage is selected by sliding the A.C. VOLTAGE SELEC-
TOR switch to the desired voltage setting.
ECU initial Setting
Be sure to make the ECU Initial Settings before making any connections
to the ECU.
CROSSOVER - 100Hz
PHASE - Full counterclockwise
LEVEL — 12 o'clock (50%)
LOW CUT - 35Hz
HIGH PASS FREQUENCY - see below
The ECU contains a passive 6dB/octave high pass filter which rolls off low
frequency energy to the satellites at 140Hz. This is required so the satellites
do not overload due to excessive low frequency energy which could cause
bottoming of the drivers and excessive distortion.
Since amplifiers have varying input impedances (ranging from 5K ohms
(rare) to 100K ohms, or higher) it becomes necessary to select the correct
value of capacitance in order to achieve the desired corner (crossover) point
of 140Hz. The amplifier's input impedance plus the amount of capacitance in
the circuit determines the actual crossover point. You may determine the input
impedance of your satellite speaker power amplifier by referring to your
owner's manual, or contacting the amplifier manufacturer.
As the impedance drops, the required capacitance has to increase in order
to maintain the recommended 140Hz crossover frequency. If the various "dip
switches" on the ECU are not properly set (for example, if too much
capacitance is added), the satellites could receive too much low frequency
energy because the crossover frequency will move down, and this can result
in satellite woofer bottoming, distortion, the inability of the satellites to play
loudly, or even excessive heaviness in the mid-bass because the satellites in
combination with the subwoofer are producing more low frequency energy
than what is ideal.
Too little capacitance will move the crossover point to a higher than
optimum frequency causing the sound to become thin and lacking in middle
bass timbre.
The chart is a recommended starting point. If you feel that you have the
capacity to identify nuances in sonic balance, you can trim the crossover
frequency by adding, or deleting capacitance (by changing switches) until the
sonic balance blends uniformly with the subwoofer, your room and personal
preference.
NOTE: The switches are closed in the down position. See figure 5 for a
schematic of the switch operation.
Input Impedance Switch Switch Switch Switch Switch Switch Shunt
Range in Ohms 6 5 4 3 2 1 'Resistor*
8-12K DOWN DOWN UP DOWN DOWN COWN -
12-18K UP UP DOWN DOWN DOWN DOWN
16-24K UP UP DOWN UP DOWN DOWN
26-40K UP UP DOWN UP UP DOWN
40-60K UP UP UP UP uP DOWN a
70-80K UP UP UP UP UP DOWN 200K
80-120K UP uP DOWN UP UP UP. a
120-200K uP UP UP UP UP DOWN 68K
200-S00K UP UP UP UP UP DOWN 56K
500K-1 Meg uP UP UP UP UP DOWN 51K