Infinity BU-1 User Manual

Owner’s Manual

Part # 930-7304

®

Powered Subwoofer

Model BU-1

BU

1

THIS INFINITY PRODUCT IS DESIGNED FOR 120-VOLT USE ONLY! FOR DETAILED SAFETY PRECAUTIONS,
PLEASE SEE PAGE 13 IN THIS OWNER'S MANUAL FOR “IMPORTANT SAFETY INSTRUCTIONS.”

The lightning flash with arrowhead

symbol, within an equilateral
triangle, is intended to alert the
user to the presence of uninsulated
“dangerous voltage” within the
product’s enclosure that may be of
sufficient magnitude to constitute
a risk of electric shock to persons.

The exclamation point within
an equilateral triangle is
intended to alert the user
to the presence of important
operating and maintenance
(servicing) instructions in the
literature accompanying the
product.

L’éclair avec le symbole de la flèche, placé dans les limites dun triangel équilatéral est
prévu pour avertir l’utilisateur de la présence de “tension dangereuse” non isolée dans
l’enceinte du produit qui pourrait être d’une importance suffisante pour présenter un
resque d’électrocution aux personnes.

Le point d’exclamation dans un triangel équilateral est prévu pour avertir l’utilisateur
de la présence d’instructions importantes pour les opérations et l’entretien (service)
dans les manuels fournis avec l’appareli.

ATTENTION: POUR EVITER LES CHOCS ELECTRIQUES, INTRODUIRE

LA LAME LA PLUS LARGE DE LA FICHE DANS LA BORNE

CORRESPONDANTE DE LA PRISE ET POUSSER JUSQUAU FOND.

!

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

WARNING: SHOCK HAZARD, DO NOT OPEN.

AVIS: RISQUE DE CHOC ELECTIQUE – NE PAS OUVRIR.

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK

DO NOT REMOVE COVER (0R BACK)

NO USER SERVICEABLE PARTS INSIDE

REFER SERVICING TO QUALIFIED PERSONNEL

IMPORTANT SAFETY INSTRUCTIONS

1) Read Instructions – All the safety and operating instructions should be
read before the product is operated.

2) Retain Instructions – The safety and operating instructions should be
retained for future reference.

3) Heed Warnings – All warnings on the product and in the operating
instructions should be adhered to.

4) Follow Instructions – All operating and use instructions should be
followed.

5) Cleaning – Unplug this product from the wall outlet before cleaning. Do
not use liquid cleaners or aerosol cleaners. Use a damp cloth for cleaning.

Exception: A product that is meant for uninterrupted service and that for
some specific reason, such as the possibility of the loss of an authorization
code for a CATV Converter, is not intended to be unplugged by the user for
cleaning or any other purpose, may exclude the reference to unplugging the
product in the cleaning description otherwise required in number 5.

6) Attachments – Do not use attachments not recommended by the product
manufacturer as they may cause hazards.

7) Water and Moisture – Do not use this product near water – for example,
near a bathtub, washbowl, kitchen sink, or laundry tub; in a wet basement;
or near a swimming pool; and the like.

8) Accessories – Do not place this product on an
unstable cart, stand, tripod, bracket, or table. The
product may fall, causing serious injury to a
child or adult, and serious damage to the
product. Use only with a cart, stand, tripod,
bracket, or table recommended by the
manufacturer, or sold with the product. Any
mounting of the product should follow the
manufacturer’s instructions, and should use
a mounting accessory recommended by the
manufacturer.

9) A product and cart combination should be
moved with care. Quick stop, excessive force, and

uneven surfaces may cause the product and cart
combination to overturn.

10) Ventilation – Slots and openings in the cabinet are provided for
ventilation and to ensure reliable operation of the product and to protect it
from overheating, and these openings must not be blocked or covered. The
openings should never be blocked by placing the product on a bed, sofa, rug,
or other similar surface. This product should not be placed in a built-in
installation such as a bookcase or rack unless proper ventilation is provided or
the manufacturer’s instructions have been adhered to.

11) Power Sources – This product should be operated only from the type of
power source indicated on the marking label. If you are not sure of the type
of power supply to your home, consult your product dealer or local power
company. For products intended to operate from battery power, or other
sources, refer to the operating instructions.

12) Grounding or Polarization – This product may be equipped with a
polarized alternating-current line plug (a plug having one blade wider than
the other). This plug will fit into the power outlet only one way. This is a
safety feature. If you are unable to insert the plug fully into the outlet, try
reversing the plug. If the plug should still fail to fit, contact your electrician to
replace your obsolete outlet. Do not defeat the safety purpose of the polarized
plug.

13) Power-Cord Protection – Power-supply cords should be routed so that
they are not likely to be walked on or pinched by items placed upon or
against them, paying particular attention to cords at plugs, convenience
receptacles, and the point where they exit from the product.

14) Outdoor Antenna Grounding – If an outside antenna or cable system is
connected to the product, be sure the antenna or cable system is grounded so
as to provide some protection against voltage surges and built-up static
charges. Article 810 of the National Electrical Code, ANSI/NFPA 70,
provides information with regard to proper grounding of the mast and
supporting structure, grounding of the lead-in wire to an antenna discharge
unit, size for grounding conductors, location of antenna-discharge unit,
connection to grounding electrodes, and requirements for the grounding
electrode. See Figure A.

15) Lightning – For added protection for this product during a lightning
storm, or when it is left unattended and unused for long periods of time,
unplug it from the wall outlet and disconnect the antenna or cable system.
This will prevent damage to the product due to lightning and power-line
surges.

16) Power Lines – An outside antenna system should not be located in the
vicinity of overhead power lines or other electric light or power circuits, or

where it can fall into such power lines or circuits. When installing an outside
antenna system, extreme care should be taken to keep from touching such

power lines or circuits as contact with them might be fatal.

17) Overloading – Do not overload wall outlets, extension cords, or integral

convenience receptacles as this can result in a risk of fire or electric shock.

18) Object and Liquid Entry – Never push objects of any kind into this

product through openings as they may touch dangerous voltage points or
short-out parts that could result in a fire or electric shock. Never spill liquid
of any kind on the product.

19) Servicing – Do not attempt to service this product yourself as opening or

removing covers may expose you to dangerous voltage or other hazards. Refer
all servicing to qualified service personnel.

20) Damage Requiring Service – Unplug this product from the wall outlet

and refer servicing to qualified service personnel under the following
conditions:

a) When the power-supply cord or plug is damaged.
b) If liquid has been spilled, or objects have fallen into the product.
c) If the product has been exposed to rain or water.
d) If the product does not operate normally by following the operating

instructions. Adjust only those controls that are covered by the operating
instructions as an improper adjustment of other controls may result in
damage and will often require extensive work by a qualified technician to
restore the product to its normal operation.

e) If the product has been dropped or damaged in any way.
f) When the product exhibits a distinct change in performance – this

indicates a need for service.

21) Replacement Parts – When replacement parts are required, be sure the

service technician has used replacement parts specified by the manufacturer or
that have the same characteristics as the original part. Unauthorized
substitutions may result in fire, electric shock, or other hazards.

22) Safety Check – Upon completion of any service or repairs to this

product, ask the service technician to perform safety checks to determine that
the product is in proper operating condition.

23) Wall or Ceiling Mounting – The product should be mounted to a wall

or ceiling only as recommended by the manufacturer.

24) Heat – The product should be situated away from heat sources such as

radiators, heat registers, stoves, or other products (including amplifiers) that
produce heat.

ANTENNA
LEAD-IN
WIRE

GROUND

CLAMP

ELECTRIC

SERVICE

EQUIPMENT

ANTENNA
DISCHARGE UNIT
(NEC SECTION 810-21)

GROUNDING CONDUCTORS
(NEC SECTION 810-21)

GROUND CLAMPS

POWER SERVICE GROUNDING
ELECTRODE SYSTEM
(NEC SECTION 810-21)

Figure A

Powered Subwoofer BU-1 – Owner’s Manual ◆1

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INTRODUCTION

The Infinity BU-1 Powered Subwoofer has been designed to enhance the bass frequencies of any
audio system. This subwoofer may be used with speakers of any size. Obviously, the greatest bass
enhancement will be achieved when the subwoofer is connected with speakers that do not have
the capability to create deep bass. This subwoofer may be used individually, or combined with
another BU-1 for even more impressive reproduction of bass frequencies (i.e., one subwoofer
near the satellite speakers and a second subwoofer behind the primary listening area, or both
subwoofers up front).

The BU-1 is a self-powered system utilizing a solid-state, low-frequency monophonic amplifier
driving a specially designed woofer mounted within a structurally rigid, tuned port enclosure.

UNPACKING THE SUBWOOFER

Check your subwoofer carefully. If it has been damaged in transit, report the damage
immediately by calling your dealer and/or the trucking firm that delivered it.

To prevent fire or shock hazard, DO NOT EXPOSE THIS SUBWOOFER SYSTEM TO RAIN
OR EXCESSIVE MOISTURE. To avoid electric shock, DO NOT OPEN THE SUBWOOFER!
There are no user serviceable parts inside. Observe all warnings and cautions.

A FEW SUGGESTIONS

We recommend that you not operate your speakers or subwoofer with the bass, treble and
loudness controls set to full boost. This will place undue strain on your electronics and speakers
and could damage them.

The volume control setting on your preamplifier or stereo receiver is not a specific indication of
the overall loudness level of the speakers. The only important consideration is the loudness
level at which the system can be played regardless of where the volume control is set.

Always turn down the volume control setting on your preamplifier or stereo when changing a
cassette or CD, or switching inputs to AM or FM operation. Excessively loud transients (clicks
or popping sounds) can damage the satellite speakers and possibly the subwoofer.

Whenever changing cables, pulling plugs, etc., ALWAYS TURN OFF ALL EQUIPMENT,
including the subwoofer. This prevents transients from entering the speakers and prevents
electrical energy from reaching you. Keep all connections out of the reach of children.

2 ◆Powered Subwoofer BU-1 – Owner’s Manual

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POSITIONING

Since the installation of a subwoofer is somewhat more complicated than installing full-range
speakers, it is essential you read this section very carefully prior to connecting the subwoofer to
your system. Should you have questions relating to your installation, it is advisable to call either
your dealer or Infinity's Customer Service Department for advice.

The performance of the subwoofer is directly related to its placement in the listening room and
how you align the subwoofer with its satellite speakers. Setting the volume of the subwoofer in
relationship to the left and right speakers is also of critical importance because it is essential that
the subwoofer integrates smoothly with the entire system. Setting the subwoofer’s volume level
too high will result in an overpowering, boomy bass. Setting the volume level too low will
negate the effect of the subwoofer.

The metal plate acts as the heat sink for the subwoofer’s internal amplifier. Do not place pillows
or other objects against it.

We recommend placing the BU-1 at least 2 to 3 feet away from a television or a computer’s disc­drive system to prevent smearing the colors of the TV picture or erasing of the magnetic drive.

Here are several additional facts on installation that may prove useful. It is generally believed by
most audio authorities that low frequencies (below 125Hz) are nondirectional and, therefore,
placement of a subwoofer within any listening room is not critical. While in theory it is true that
the larger wavelengths of extremely low frequencies are basically non-directional, the fact is that
when installing a subwoofer within the limited confines of a room, reflections, standing waves
and absorptions generated within the room will strongly influence the performance of any
subwoofer system. As a result, specific location of the subwoofer becomes important, and we
strongly recommend that you experiment with placement before choosing a final location.

Placement will depend upon your room and the amount and quality of bass required (for
example, whether or not your room permits placement of the subwoofer near either satellite).
Never place the port too close to a wall or piece of furniture as this will prevent the port from
operating properly. Since the port is an integral part of the subwoofer’s design, it should always
be permitted free access to the listening room without obstruction to the pressure emerging
from it. Careful experimentation will enable you to determine the best position for the
subwoofer (see useful hints, next page).