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B-20 POWERED Modular Stereo Subwoofer System Owners Manual B-20
POWERED Modular
Stereo
Subwoofer System
Owners Manual
Copyright 2001 NHTPro, a Recoton Corporation Brand
B-20 Control Amplifier Serial Number:
B-20 Subwoofer Serial Number:
B-20 Subwoofer Serial Number: Safety Instructions -- Please Read First
CAUTION: To reduce the risk of electric shock, do not
remove the cover. No user serviceable parts are inside; refer
servicing to qualified personnel.
WARNING: To reduce the risk of fire or electric shock do
not expose this appliance to rain or moisture.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
WARNING: SHOCK HAZARD-DO NOT OPEN.
AVIS: RISQUE DU CHOC ELECTRONIQUE-
NE PAS OUVRIR.
This symbol, wherever it appears, alerts you
to the presence of uninsulated dangerous
voltage inside the enclosure that may be
sufficient to constitute a risk of electric
shock.
This symbol, wherever it appears, alerts you
to important operating and maintenance
instructions in the accompanying literature.
Read the manual.
DETAILED SAFETY INSTRUCTIONS:
All the safety and operation instructions should be read before the appliance is operated.
Retain Instructions:
The safety and operating instructions should be retained for future reference.
Heed Warnings:
All warnings on the appliance and in the operating instructions should be adhered to.
Follow Instructions:
All operation and user instructions should be followed.
Water and Moisture:
The appliance should not be used near water (e.g. near a bathtub, washbowl, kitchen sink. laundry tub, in a wet basement,
or near a swimming pool etc.).
Ventilation:
The appliance should be situated so that its location or position does not interfere with its proper ventilation. For example,
the appliance should not be situated on a bed, sofa, rug, or similar surface that may block the ventilation openings, or
placed in a built-in installation, such as a bookcase or cabinet that may impede the flow of air through the ventilation
openings.
Heat:
The appliance should be situated away from heat sources such as radiators, heat registers, stoves, or other appliances
(including other amplifiers) that produce heat.
Power Source:
The appliance should only be connected to a power supply of the type described in the operating instructions or as marked
on the appliance.
Grounding and Polarization:
Precautions should be taken so that the grounding or the polarization means of the appliance is not defeated.
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 and plugs, convenience receptacles and the point where they exit from the
appliance.
Cleaning:
The appliance should be cleaned only as recommended by the manufacturer.
Nonuse Periods:
The power cord of the appliance should be unplugged from the outlet when left unused for a long period of time.
Object and Liquid Entry:
Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through openings.
Damage Requiring Service:
The appliance should be serviced by qualified service personnel when;
The power supply cord or the plug has been damaged; or
Objects have fallen, or liquid has been spilled into the appliance; or
The appliance has been exposed to rain; or
The appliance does not appear to operate normally or exhibits a change in performance; or
The appliance has been dropped, or the enclosure damaged.
Servicing:
The user should not attempt to service the appliance beyond what is described in the Operating Instructions. All other
servicing should be referred to qualified service personnel. INTRODUCTION:
GETTING STARTED:
Thanks for your purchase, and congratulations on your selection of the B-20 active modular subwoofer system. The B-20
will add incredible dynamics and extended bass response to any pair of monitors, or to the
Your
time invested in learning about the B-20s features and capabilities will reward you with the best possible performance.
Now would also be an excellent time to fill out and send in your warranty registration card or, optionally, register your
purchase online at www.vergenceaudio.com under the Support section. This action will automatically extend both the parts
and labor warranty for an additional two years for a total of three years! If at any time, you require assistance, call our
customer service hotline at (800)-NHT-9993 (648-9993 or e-mail us at tech@nhtpro.com.
LFE channel for surround mixing.
Although the B-20 was designed to mate specifically with the Vergence A-20 stereo monitors and C-20 center channel
monitor, its extensive control set makes it an ideal addition to near or mid- field monitor system you may already own.
The B-20 is unique in that it combines a dedicated control amplifier with subwoofer cabinets, using controlled impedance
cables that actually form part of the crossover network. By designing the system as an integral package of control amp,
cables, and subwoofers, many of the advantages of self-powered subwoofers can be realized without the usual attendant
performance compromises.
WARNING:
The following are included in the Control Amplifier carton:
1 - Control Amplifier
2 - 20' Monitor Output Cables
1 - 6' IEC Power Cord
4 - 10-32 Rack Mounting Screws
1 - Warranty Registration Card
8 - Plastic Insulating Washers
The B-20 subwoofers must only be used with the B-20 Control Amp, cables, and vice versa.
INITIAL Installation:
AMP MOUNTING: The B-20 Control Amplifier may be used on a shelf, or mounted in a standard 19 equipment rack
using the screws and washers supplied. For rack mounting, remove and retain the four feet from the bottom of the amp chassis
using a #2 Philips screwdriver. Refer to figure 1 above. Two vertical rack spaces are required, but we recommend you leave
at least one additional open space above
below the B-20 Control Amplifier for improved cooling, as you would with any
high power amplifier. For table or shelf use, the four feet must remain attached to allow for air circulation.
SUBWOOFER FEET: For best performance, the subwoofers need stable footing. Install three speaker cones into the
threaded inserts in the bottom of each subwoofer, or, if the subwoofer is to be placed on a hardwood floor, apply rubber feet.
The cone points are sharp so please use caution. For now, position each B-20 subwoofers next to the left and right monitors.
For more detailed speaker placement tips, see page 7.
and
Rack Rail
C-20
Amplifier
Front Panel
Screws
Insulating
Washers
Fig. 1: Rack Mounting Detail
Fig. 2: Cone Feet Installation Input Sensitivity Control:
Monitor High Pass (HP) Frequency Control:
Sub Low Pass Frequency Control:
Bypass LED:
Power LED:
Master Power Switch:
This control affects both the subwoofer input and the high pass circuit. There are five settings: +11dB, +4dB, -3dB and -10dB and M ( Mute).
Typically +11dB and +4dB are used with higher output professional gear such as mixers, while the -3dB and -10dB positions match the levels used in
consumer products such as CD players and sound cards. Check the output specifications of the source equipment you are connecting to the B-20 Control
Amplifier and set accordingly.
This control sets the lowest frequency you wish to send to the main left and right monitors youre using with the B-20. There are 5 settings; BY (Bypass),
35Hz, 60Hz, 85Hz and 110Hz. Selecting the proper switch position (see the Initial Control Settings section on Pg. 6) will help blend the overall
system response and increase power handling. Engaging BY (bypass) turns off the high pass circuit, and sends fullrange sound to the monitors.
This control adjusts the highest frequency the subwoofers reproduce, allowing you to match the precise point where your monitors low end rolls off.
The low pass control is typically set to correspond with the Mon. High Pass but experimenting may produce better response in your system The BY
(Bypass) setting allows you to disengage the control if you use external bass management, or to match some surround protocols.
The subwoofer level control matches the B-20 ouput level to the monitors output level. This control differs from most as it doesnt turn the woofer all
the way off (use Bypass), but offers a 20dB range of adjustment. When set fully counter clockwise, this control attenuates the sub output by 20dB.
This amber LED is illuminated when the B-20 Control Amplifier is in the bypass mode, indicating that there is no subwoofer output, and a