Infinity Infinity Modulus User manual

We at Infinity Systems, Inc. would like to take this opportunity to thank you
for choosing the Modulus Subwoofer and commend you on your choice. The
Modulus Subwoofer is a fully self-contained, 250 watt, servo-controlled sub-
woofer system able to achieve levels of performance that are unrivaled by
similar systems. In order to bring out the best from your Modulus Sub-
woofer, itis important that you read through this manual before connect-
ing and operating your subwoofer.
If any of the instructions in this manual are not clear or if you have any
additional questions about installing or using your Modulus Subwoofer, you
should contact your dealer or Infinity Systems for clarification.
UNPACKING THE SUBWOOFER
As you have undoubtedly noted, the subwoofer is extremely heavy, so
Please use caution when unpacking and handling it. Help from a second
person is recommended when removing the subwoofer from its shipping
carton.
The subwoofer cabinet is finished in a baked polyester resin that is durable
and resistant to scratching and marring. However, the finish can be damaged
if improperly handled. Care of the subwoofer cabinet is contained in a special
section later in this manual.
If the subwoofer, or any of its associated parts was damaged in transit,
contact your dealer, or carrier immediately.
The contents of the subwoofer carton should be checked to ensure that
the following items are included:
1. Subwoofer
. Electronic Control Unit (ECU)
. Four (4) black metal isolation feet
. Four (4) black plastic isolation feet covers
. One (1) packet of silicone adhesive
6. One (1) 25 foot cable with DIN connectors at each end.
The subwoofer packing materials should be saved in case the subwoofer
needs to be repackaged for reshipment at a later date.
As a minimum, save the packaging materials until you are sure your
subwoofer is not damaged and is operating properly.
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THE SUBWOOFER
The subwoofer includes the speaker, the power amplifier, and the input
panel. The power amplifier is the black aluminum structure located on the
tight-front corner of the enclosure. The input panel is located on the bottom of
the enclosure and the speaker is located behind the enclosure grille. Also
located behind the grille, in the lower-right corner, is a red LED to indicate
when the subwoofer input panel POWER switch is set to ON. This red LED
indicates that the subwoofer is in the standby mode and ready to play.
Subwoofer Input Panel
The subwoofer input panel (figure 1), located on the bottom of the sub-
woofer, contains the controls and connectors required to make your subwoofer
work with your system.
INPUT connector — is a DIN connector that is used to connect the
subwoofer to the ECU.
POWER switch — turns the A.C. power on and off.
A.C. VOLTAGE SELECTOR -— sets the subwoofers power supply to
conform with the A.C. line voltage at the user's location. The subwoofer is
normally shipped with this switch set to 110 volts.
A.C. Line Cord - connects the A.C. power from the wall outlet to the
subwoofer.
Power ON LED - lights when the POWER is set to ON.
ELECTRONIC CONTROL UNIT
The Electronic Control Unit (ECU) is an electronic device that is connected
between your system preamplifier and the subwoofer. The ECU controls the
subwoofer allowing the owner to make adjustments for optimum output
regardless of the placement of the subwoofer.
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AC. VOLTAGE SELECTOR
CAUTION
CONTRO
Figure 1. Subwoofer Input Panel
ECU Front Panel
The ECU front panel (figure 2) contains the controls and switches for
crossover, phase, level and power to your subwoofer.
CROSSOVER contro! — sets the upper limit of the subwoofer frequency
response. The upper limit is where the subwoofer begins to roll off to meet
the low frequency output of your satellite speakers.
PHASE contro! — used to optimize the blend of the subwoofer with the
satellites when the subwoofer cannot be placed in the best room location
due to room layout or space. The phase control is variable from 0 to 180°.
The contro! is normally set fully counterclockwise (0), but can be set
anywhere within its rotation.
LEVEL control — sets the subwoofer volume.
LOW CUT selector — rolls off the response of the subwoofer at either 22Hz,
or 35Hz. The normal setting is 35Hz. However, if a particular recording
does not have rumble, or if the volume of the overall music being played
is not excessively loud, then 22Hz can be used.
POWER switch — turns the A.C. power to the ECU on and off and activates
the subwoofer.
Power ON LED - lights when power is applied to the ECU.
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Figure 2. ECU Front Panel
ECU Input/Output Panel
The ECU input/output panel (figure 3) contains the switches and jacks that
allows you to connect the ECU to your system and set up the voltage and high
pass circuits.
HIGH PASS FREQUENCY DIP switches — used to select the ECU internal
capacitor value to match the satellite amplifier input impedance. The
capacitor value selected will create a 140Hz cutoff frequency at 6dB/oc-
tave. A complete discussion of the high pass circuit is contained in the ECU
Initial Settings section of this manual.
OUTPUT connector — supplies subwoofer A.C. control voltage and the low
frequency signal to the subwoofer power amplifier.

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.
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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

5
7 a Pass
INPUT OUTPUT
——+ tf —— .
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° 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.

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Figure 7. Typical Starting Position Layout
MOST BASS MODERATE BASS LESS BASS
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0 8
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Figure 8. Bass Response With Relation To Wall(s)
OPERATING THE SUBWOOFER
Power Up
1. Plug all components into an A.C. outlet.
2. On the subwoofer input panel, setthe POWER switch to ON. The power
LED
on
the
input
panel
will
display
a
RED
light.
The
red
LED
behind
the
grille
indicates that the subwoofer is on standby.
3. Turn on the power to the audio components.
4.
Set
the
ECU
POWER
switch
to
ON.
The
ECU
activates
the
subwoofer
and
turns
off
the
red
LED
behind
the
grille.
Listening to Your System
1. Turn the VOLUME control on your preamplifier to a comfortable listen-
ing level and begin playing a record, CD, or cassette that is rich in bass
information.
2. Experiment with the controls on the ECU until you are pleased with the
sound. The bass should enhance but not overpower the rest of the music.
3. Experiment with the placement of the subwoofer. Minor position adjust-
ments may produce results that are even more pleasing.
The 0 to 180° phase control located on the front panel of the ECU should
be rotated to optimize the blend of the subwoofer and satellites. There will be
a position within the full rotation of this control which will yield the best results.
As you rotate the control listen for the following:
1. Maximum bass output
2. Greater low frequency definition
3. A seamless transition between the subwoofer and the satellites.
You may experience all three sonic characteristics or only one or two. The
phase control may be set anywhere within its rotation for optimum perfor-
mance.
Impact of Tone Control on Your System
The tone controls on your audio components should be used with the
utmost discretion. Excessive boost can demand hundreds of watts in the bass
region. In the flat position or with the tone controls switched out of your system,
as little as 10 watts can produce impressive and realistic listening levels. The
remaining power amplifier capacity is in reserve for power peaks on sharp
transients and powerful crescendos. With the flexibility of the ECU, you should
be able to leave the bass control of your preamp at the flat position.
CARE OF THE ENCLOSURE
The enclosure of your subwoofer is finished with a durable, high-gloss,
scratch-resistant polyester resin. The finish should be kept clean by oc-
casionally dusting with a lint-free cotton cloth. Fingerprints and other minor
blemishes may be removed with a lint-free cloth dampened with ammonia-free
window cleaner. Do not use abrasive or chemical cleaners.
The grille may be cleaned by gently vacuuming with a furniture brush
attachment.
IN CASE OF TROUBLE
If the subwoofer sounds distorted, stops playing, or otherwise seems to be
malfunctioning, first determine if the problem is in the subwoofer, wiring, or
other audio components. If the problem also affects the satellite speakers, the
cause is most likely in your electronics. If it is only noticed in the subwoofer,
make sure that all connecting cables are correct and in proper working
condition. Make sure the subwoofer and ECU are plugged in and turned on.
Check the subwoofer A.C. fuse. If everything seems to be in good working
order and the subwoofer still malfunctions, DO NOT ATTEMPT ANY
REPAIRS! Contact your dealer for the nearest authorized Infinity Service
Center.
If you do not have a service center near you, contact:
Infinity's Customer Service
[phone]
or write:
Infinity Customer Service
9409 Owensmouth Avenue
Chatsworth, CA, 91311 (USA).
DO NOT SHIP YOUR SUBWOOFER OR ECU FOR SERVICE WITHOUT
PRIOR AUTHORIZATION.

LIMITED WARRANTY
Who is protected by the warranty?
Your Infinity Warranty protects the original retail purchaser and all subsequent owners, during the stated warranty period, from any failure as a
result of an original manufacturing defect so long as: (1) your Infinity product was purchased within the fifty United States, or purchased by military
personnel from an authorized military outlet and (2) the original dated bill of sale is presented whenever service is required during the warranty
period. This warranty does not apply to products purchased elsewhere; other purchasers should contact their local Infinity distributor for warranty
information.
How long Is the warranty period?
Warranty Period
Product Type Labor Parts
Electronic Products 1 year 1 year
Speaker Systems 5 years 5 years
What does the Infinity Warranty cover?
Except as specified below, the Infinity Warranty covers ail defects in original materials and workmanship. The following are not covered: Damage
caused by accident, misuse, abuse, neglect, product modification; damage occurring during shipment; damage caused by failure to follow
instructions
in
your
owner's
manual,
including
failure
to
perform
recommended
periadic
or
routine
maintenance;
damage
resulting
from
repairs
by someone not authorized by Infinity; claims based upon any misrepresentations by the seller; and any Infinity product on which the serial number
has been altered, defaced or removed.
Who pays for what?
During the period that both parts and labor are covered by this warranty, Infinity will pay all of the labor and material expenses to repair a warrantable
defect; during the period that parts ONLY are covered by this warranty, Infinity will pay for all materials to correct a warranted defect, but you
must pay for the labor charges.
How can warranty service be obtained?
In the event that your Infinity product requires service, you should first contact the Infinity dealer from whom the product was purchased or if this
is
not
practical,
contact
us
at
infinity
(Attn:
Customer
Service)
at
9409
Owensmouth
Avenue,
Chatsworth,
CA
91311
(818)
709-9400.
We
may
direct you to an authorized service center for Infinity products or ask you to send your unit to us for repair. In either case you will have to present
your original ill of sale to establish warranty coverage. Do not send your product to us without prior authorization.
You
are
responsible
for
transporting
your
product
for
repair
and
for
payment
of
all
shipping
charges.
However,
Infinity
will
pay
the
return
shipping
charges
if
the
repairs
are
covered
by
the
warranty.
If
you
experience
difficulty
in
transporting
your
product,
please
advise
us
and
we
may
suggest
alternative
procedures.
LIMITATION OF IMPLIED WARRANTIES: All implied warranties, including fitness for a particular purpose and merchantability are limited
in duration to the length of the warranty period for your product.
LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES: Infinity is not responsible for any incidental or consequential damage
of any kind. Our liability is limited to the repair or replacement, at our option, of a defective product.
Some states do not allow limitations on how long an implied warranty lasts and/or do not allow the exclusion of incidental or
consequential damage, so the above limitations or exclusions may not apply to you.
This warranty gives you specific legal rights and you may also have other rights which vary from state to state.
NOTE: In the event that there is a difference between this warranty and the provisions in your owner’s manual, the terms of this warranty
will prevail.
WINfinity
We get you back to what it’s all about. Music.
INFINITY SYSTEMS, INC. + 9409 Owensmouth Avenue + Chatsworth, CA 91311 U.S.A. + [phone]
H/M 71660 P/N 930-4097