Fostex NX-6A User Manual

Model

432656

Owner’s Manual

Introduction

Thank you very much for purchasing the Fostex Model NX-6A.
The NX-6A is a nearfield studio monitor with a built-in power amplifier. It delivers a
musical and highly accurate sound, allowing you to check a sound thoroughly to a fine
nuance.

The NX-6A employs a 160-mm woofer (shielded type) which adopts the latest diaphragm
technology and a 20-mm hard dome tweeter (shielded type) which features a magne­sium diaphragm. It features bi-amplifier design (60W for the woofer, 40W for the tweeter).

In the enclosure, HP sound reflectors are installed for natural low frequency reproduc­tion. Thanks to the time-alignment construction on the buffle surface, as well as the
flush surface design, each sound image is pinpointed accurately.

From dynamic low frequencies to natural and smooth high frequencies, the NX-6A re­produces the whole frequency range faithfully. It is the ideal monitor for recording
studios.

NX-6A (Powered Near Field Studio Monitor)

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,

DO NOT REMOVE COVER (OR BACK).

NO USER - SERVICEABLE PARTS INSIDE.

REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

"WARNING"

"TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR
MOISTURE."

SAFETY INSTRUCTIONS

1. Read Instructions - All the safety and operating instructions
should be read before the appliance is operated.

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

3. Heed Warnings - All warnings on the appliance and in the
operating instructions should be adhered to.

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

5. Water and Moisture - The appliance should not be used near
water - for example, near a bathtub, washbowl, kitchen sink,
laundry tub, in a wet basement, or near a swimming pool, and
the like.

6. Carts and Stands - The appliance should be used only with a
cart or stand that is recommended by the manufacturer.

An appliance and cart combination should be moved with care.
Quick stops, excessive force, and uneven surfaces may cause
the appliance and cart combination to overturn.

7. Wall or Ceiling Mounting - The appliance should be mounted to
a wall or ceiling only as recommended by the manufacturer.

8. Ventilation - The appliance should be situated so that its location
or position dose 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.

9. Heat - The appliance should be situated away from heat sources
such as radiators, heat registers, stoves, or other appliances
(including amplifiers) that produce heat.

10. Power Sources - The appliance should be connected to a power
supply only of the type described in the operating instructions or
as marked on the appliance.

CAUTION:

TO PREVENT ELECTRIC SHOCK, MATCH WIDE BLADE OF
PLUG TO WIDE SLOT, FULLY INSERT.

ATTENTION:

POUR EVITER LES CHOCS ELECTRIQUES, INTRODUIRE
LA LAME LA PLUS LARGE DE LA FICHE DANS LA BORNE
CORRESPONDANTE DE LA PRISE ET POUSSER JUSQU'
AU FOND.

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 appliance.

11. Grounding or Polarization - The precautions that should be taken
so that the grounding or polarization means of an appliance is
not defeated.

12. 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 appliance.

13. Cleaning - The appliance should be cleaned only as
recommended by the manufacturer.

14. Nonuse Periods - The power cord of the appliance should be
unplugged from the outlet when left unused for a long period of
time.

15. Object and Liquid Entry - Care should be taken so that objects
do not fall and liquids are not spilled into the enclosure through
openings.

16. Damage Requiring Service - The appliance should be serviced
by qualified service personnel when:

A. The power supply cord or the plug has been damaged; or
B. Objects have fallen, or liquid has been spilled into the appliance; or
C. The appliance has been exposed to rain; or
D. The appliance does not appear to operate normally or

exhibits a marked change in performance; or

E. The appliance has been dropped, or the enclosure damaged.

17. Servicing - The user should not attempt to service the appliance
beyond that described in the operating instructions.
All other servicing should be referred to qualified service
personnel.

18. The appliance should be situated away from drops of water or
spray of water.

19. Objects containing liquid such as vase must not be put on the
appliance.

20. The appliance is not completely isolated from the power supply
even if the power switch is at off position.

21. Apparatus shall not be exposed to dripping or splashing and no
objects filled with liquids, such as vases, shall be placed on the
apparatus.

22. Only use attachments/accessories specified by the
manufacturer.

23. An appliance with a protective earth terminal should be
connected to a mains outlet with a protective earth connection.

24. Where the MAINS plug or an appliance coupler is used as the
disconnect device, the disconnect device shall remain readily
operable.

2

NX-6A (Powered Near Field Studio Monitor)

Important Safety Instructions

1) Read these instructions.

2) Keep these instructions.

3) Heed all warnings.

4) Follow all instructions.

5) Do not use this apparatus near water.

6) Clean only with dry cloth.

7) Do not block any ventilation openings.
Install in accordance with the
manufacturer's instructions.

8) Do not install near any heat sources such
as radiators, heat registers, stoves, or
other apparatus (including amplifiers) that
produce heat.

9) Do not defeat the safety purpose of the
polarized or grounding-type plug.
A polarized plug has two blades with one
wider than the other. A grounding type
plug has two blades and a third grounding
prong. The wide blade or the third prong
are provided for your safety.
If the provided plug does not fit into your
outlet, consult an electrician for
replacement of the obsolete outlet.

11) Only use attachments/accessories
specified by the manufacturer.

12) Use only with the cart, stand, tripod,
bracket, or table specified by the
manufacturer, or sold with the apparatus.
When a cart is used, use caution when
moving the cart/apparatus combination
to avoid injury from tip-over.

13) Unplug this apparatus during lightning
storms or when unused for long periods
of time.

14) Refer all servicing to qualified service
personnel. Servicing is required when the
apparatus has been damaged in any
way, such as power-supply cord or plug
is damaged, liquid has been spilled or
objects have fallen into the apparatus, the
apparatus has been exposed to rain or
moisture, does not operate normally, or
has been dropped.

10) Protect the power cord from being walked
on or pinched particularly at plugs,
convenience receptacles, and the point
where they exit from the apparatus.

3

NX-6A (Powered Near Field Studio Monitor)

Precautions

• In the event of smoke or odors, immediately turn off
the power switch and remove the AC plug from the
outlet. Continued use under such conditions will
result in fire and/or electrical shock.
After extinction of such conditions, refer the problem
to a dealer or our service station located nearest to
you. In no events must an attempt to correct the
problem by unauthorized personnel take place.
Noncompliance with this notice may pose an extreme
danger.

• In the event of entry of water or an object into the
appliance, immediately turn off the power switch and
remove the AC plug from the AC outlet.
A dealer or our service station located nearest to you
must be contacted for reinstatement of the original
conditions. Continued use without it will result in fire
and/or electrical shock.

• In the event of electrical discontinuity and/or damage
including conductor exposure occurs to the power cord,
contact a dealer or our service station located nearest
to you for service. Continued use without it will result
in fire and/or electrical shock.

• In the even of a fall of the appliance or damage to
appliance cover, immediately remove the AC plug from
the AC outlet and contact a dealer or our service
station located nearest to you for service.
Continued use without it will result in fire and/or
electrical shock.

• Placement of the appliance where contact with water
is likely must be avoided. Otherwise, fire and/or
electrical shock will result. This precaution is
particularly important when the appliance is used
outdoors (on rainy or snowy days, on the beach or
other such places).

• No vases or cups containing water, and/or small metal
pieces must be placed on the appliance.
Spilling of water or dropping of metal pieces into the
appliance will result in fire and/or electrical shock.

• Under no circumstances, must an attempt be made to
disassemble, repair and/or alter the appliance.
Neither must the appliance cover be removed.
Otherwise, fire and/or electrical shock will result.

• No contact with the AC plug must be made after
lightning has started. Otherwise, electrical shock will
result.

• No heavy objects must be placed on the AC cord nor
the cord be routed under the appliance.
Damage to the cord will occur resulting in fire and/or
electrical shock.

• The AC cord must not be damaged, modified, twisted,
pulled and/or heated. Otherwise, the cord will be
damaged resulting in fire and/or electrical shock.

• No power voltage different from that labeled on the
appliance or specified in this owner’s manual must be
applied. The power plug must be inserted to the end
of an outlet. Otherwise, fire and/or electrical shock
will result.

• Avoid placement of the appliance in smoky or steamy
places including unusually humid or dusty places.
Otherwise, fire and/or electrical shock may result.

• The AC cord must not be routed near heat emitting
appliances. Otherwise, the cord jacket may melt
resulting in fire and/or electrical shock.

• Avoid mounting or setting the appliance on unstable
surfaces, including wobbly or slanting planes.
Contact with the falling appliance may cause injury.

• Do not leave the appliance in places where the
temperature will rise excessively, including an
automobile with windows closed or an area exposed to
direct sunlight. Otherwise, fire may result.

• This appliance is built with precision components.
Moving of the appliance must be accomplished by at
least two persons with care.

• Relocation of this appliance must occur only after the
power has been turned off and the AC plug and all
other connecting cords have been disconnected.
Otherwise, cords may be damaged resulting in fire and/
or electrical shock.

• Connection of other audio equipment to this
appliance must proceed only after power to this
appliance and equipment to be connected has been
shut off and in strict compliance with the wiring
instructions given in the manual provided with such
equipment. Use of the designated cords is also a
prerequisite.

• The loudness control must be set to the minimum
before turning this appliance on.
Otherwise, unexpectedly loud sound may be produced
resulting in impairment of hearing acuity.

• The power cord must be disconnected when not using
of this appliance for an extended period of time (a
month or longer). Otherwise, fire and/or electrical
shock may result.

• Wet hands must not touch the AC plug. Otherwise,
electrical shock may result.

• No cloth, blanket or the like must be placed over this
appliance while its power is on. Trapped heat may
result in fire.

• Maintenance of this appliance must occur only after
the AC plug has been removed. Otherwise, electrical
shock may result.

• Use of portable phones near the appliance is not
recommended. Otherwise, noise may develope in this
appliance.

• Use of this appliance near radio or TV sets may result
in the development of noise. If this is the case, keep
them apart.

4

Main features of NX-6A

• Woofer featuring the HR (Hyper Radial) diaphragm

The NX-6A employs the 160-mm woofer. It features the
highly rigid HR (Hyper Radial) diaphragm, developed by
using the latest diaphragm technology called "Radial pa­permaking technology". As a result, the NX-6A offers a rich
low frequency sound with minimum distortion.
Furthermore, by using the "UDR tangential edge" for the
woofer edge, it eliminates the unnecessary resonance and
achieves pure and clear sound reproduction (see Figure 1).

Radial paper-forming technology

Using the radial paper-forming technology, speaker dia­phragms are made from compound materials (pulp, fiber,
etc.) in a radial shape. This technology allows you to make
diaphragms with the desired thickness and strength, which
results in improving the speed and extent of a sound.

UDR (Up/Down Roll) tangential edge

A revolutionary technology is used for the NX-6A woofer
edge. The edge is created by joining up-roll and down-roll at
their tangential surfaces while utilizing FEM model analysis
to determined the optimum bonding points. The UDR tan­gential edge is adopted to the edge of the NX-6A woofer.

NX-6A (Powered Near Field Studio Monitor)

HR diaphragm

UDR tangential edge

<Figure 1>

• Tweeter f eaturing ma gnesium diaphra gm

The 20-mm hard dome tweeter employs the magnesium dia­phragm. This tweeter produces natural and extended high
frequencies, while eliminating a peculiar sound which most
metallic tweeters may produce (see Figure 2).

• HP sound reflectors

The two HP sound reflectors are installed in the enclosure
as shown in Figure 3. In the NX-6A enclosure, micron wool
is also placed appropriately.
This configuration reflects the sound in the enclosure dif­fusely and creates the condition where stationary wave is
decayed. The time alignment construction is adopted on
the buffle surface of the enclosure, which allows to position
each sound image accurately. The flush surface design elimi­nates sound blur.

HP sound reflector

Magnesium

diaphragm

<Figure 2>

• Bi-amplifier power

The NX-6A utilizes a powerful bi-amplifier design (60W
for the woofer, 40W for the tweeter). Driving each speaker
unit independently eliminates audio impurity caused by
the electric interference between the units. The built-in
power amplifier also provides functions for compensat­ing audio frequency characteristics to match the sonic
character of a room, including the low frequency (around
55Hz range) equalizer and the tweeter level control. The
power amplifier is equipped with both the balanced and
unbalanced input connectors, allowing connection to any
audio systems.

<Figure 3>

The arrangement example of the HP sound reflectors (the cut model above
shows the inside of the Fostex NF-1).

Amplifier

section

<Figure 4>

5

NX-6A (Powered Near Field Studio Monitor)

Names and functions

1. Power LED

Lights when power is turned on.

2. Output level control

Adjusts output level.

3. Tweeter level control

1

Adjusts tweeter level within a +/- 3dB range.

4. Low-frequency EQ control

Adjusts low frequency characteristics (around 55Hz range)
within a +/- 3dB range.

5. Unbalanced input terminal (Phone jack)

Accepts -10dBV unbalanced input.

2
3

6. Balanced input terminal (XLR-3-31 type)

Accepts +4dBu balanced input (hot pin is #2).

4

-∞

5
6

<CAUTION>:

input connectors cannot be used simultaneously. When the
unbalanced connector is plugged, the unbalanced input takes
priority and the balanced input is disabled.

The balanced (XLR) and the unbalanced (phone)

7

7. Heatsink

<CAUTION>:

gets extremely hot. Do not touch the heatsink in such a con­dition.

If you use the NX-6A for a long time, the heatsink

8

8. Power switch

Turn the power on or off. Make sure that the output level
control of the connected equipment is set to minimum when

9

turning on the power.

9. AC IN connector

Connects the AC cord provided.

Level controls and EQ

Output level control

VOL

Rotating the VOL control clock-

0dB

LO EQ

wise increases the output level.

MAX

(0dB)

-3

+3

Tweeter le vel control

0dB

TWEETER

-3

+3

You can use the TWEETER con­trol to adjust the tweeter level
within the range of +/- 3 dB.
The center position (0 dB) is the
nominal position. Turning the
control right boosts the tweeter
level, while turning it left drops
the level (see the graph right).
When the unit is shipped, the
TWEETER control is set to the
center (0 dB).

(dB)

110

(Hz)

Wf +3dB

Wf -3dB

50

100 200

90

70

50

10

20

Low (around 55Hz range) EQ

You can use the LO EQ control
to boost/cut the low frequency
(around 55Hz range) within the
range of +/-3 dB. Turning the
control right boosts the low fre­quencies, while turning it left
cuts the low frequencies (see
the graph below).

Tw +3dB

Tw -3dB

2k

5k 10k 20k

1k

500

50k

6

NX-6A (Powered Near Field Studio Monitor)

Enclosure positioning

Adopting the time alignment construction, as well as mounting the woofer and tweeter closely, the NX-6A pro­vides a wide monitoring area.
We recommend to install the NX-6As vertically, as shown below, not only from the point of view of audio phase
characteristics but also from the point of view of radiation of the built-in power amplifier. As a human ear is
sensitive in the left-right direction, setting the unit horizontally is undesirable from the point of view of phase
characteristics.

Vertical positioning

Horizontal positioning

• Optimal listening point and setting

To get the best of the NX-6A performance, set them at the appropriate height so that the middle point
between the center positions of the tweeter and woofer matches the listener’s ear height.
Then, orient them 15 to 30 degrees inward to form a triangle as shown in the Figure below.
The vertex of the equilateral triangle in the Figure is best listening position.

Center of the tweeter

Center of the woofer

15 to 30 degrees inward 15 to 30 degrees inward

Mid-point of the woofer and tweeter

Listener

Maintenance precautions

Be careful when cleaning speaker/enclosure surfaces!!

* No protecting grilles or covers are provided with

NX-6A. Brush off dust attached to surfaces of
speakers with soft dusters. Avoid direct fingers or
damp dust cloth contact with diaphragms.

* Stained enclosure surfaces must be wiped with

tightly wrung-out soft cloth after immersion in a
diluted detergent. Under no circumstances must
organic solvents such as paint thinner be used.

7

NX-6A (Powered Near Field Studio Monitor)

Block Diagram

INPUT (UNBAL)

-10dBV

VOL

INPUT (BAL)

+4dBu
1: GND
2: HOT

3: COLD

Specifications

<Speakers>

Enclosure system : 2-way bass-reflex system
Drivers : 160 mm woofer

: 20mm hard dome tweeter
Impedance : Woofer/6Ω, Tweeter/8Ω
Reproduction freq. range : 55Hz to 38kHz
Enclosure volume : 11 liters
Maximum output sound level : 104 dB (with VOL max./rated input)

<Amplifiers>

Output power : Low frequency amplifier: 60W

: High frequency amplifier: 40W

*Output Level : -∞ ~ MAX (0dB) controllable

Input terminals : XLR-3-31 type (balanced, Pin2: Hot),

+4dBu

: ø 6mm phone jack (unbalanced),

-10dBV
Input impedance : 10kΩ or more
Cross-over freq. : 6kHz/-18dB/oct. (Wf),

8kHz/-18dB/oct. (Tw)
Tweeter SPL adjustable level : +/- 3dB controllable
Lo-EQ level (around 55Hz range) : +/- 3dB controllable

HF POWER

LF POWER

TWEETER

WOOFER

+3dB

TWEETER

LEVEL

-3dB

0dB

LO EQ

110

90

70

(dB)

50

10 50

20

(Hz)

100 200

1k

500

0º

30º

60º

5k

2k

20k

10k

• Specifications and appearance are subject to change with
out notice for product improvement.

50k

<General>

Dimensions : 230 (W) x 350 (H) x 334 (D) mm
Weight : Approx. 13 kg
Power supply : 120VAC 60Hz, 230V ~ 50/60Hz
Power consumption : 70W

VOL

MAX

-∞

(0dB)

0dB

TWEETER

LEVEL

-3

+3

0dB

EQ

LO

-3

+3

INPUT

UNBAL

-10dBV

1:G
2:H
3:C

BAL

+4dBu

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

ELECTRIQUECHOCDE

NE PAS OUVRIR.

THE

WARNING:

FIREORELECTRIC

OF

RISK

REDUCE

TO
SHOCK,DO NOT EXPOSE THIS EQUIPMENT
TO RAIN OR MOISTURE.

POWER

ON

OFF

AC IN

334

350

230

8

NX-6A (Powered Near Field Studio Monitor)

Declaration of EC Directive

This equipment is compatible with the EMC Directive (89/336/EEC) - Directive on approximation of member nation's
ordinance concerning the electromagnetic compatibility and with the Low Voltage Directive (73/23/EEC) - Directive on
approximation of member nation's ordinance concerning electric equipment designed to be used within the specified
voltage range.

The Affect of Immunity on This Equipment

The affect of the European Specification EN61000-6-1 (coexistence of electromagnetic waves - common immunity
specification) on this equipment are as shown below.

In the electrical fast transient/burst requirements, surge, conducted disturbances by radio-frequency fields, power frequency
magnetic field, radiate electromagnetic field requirements and static electricity discharging environment, this could be affected by
generation of noise in some cases.

FOSTEX DISTRIBUTORS LIST IN EUROPE

* Including non-EU countries (as of January, 2005)

<AUSTRIA>

NAME: ATEC Audio-u. Videogeraete VertriebsgesmbH.
ADD: Im Winkel 5, A-2325 Velm, Austria
TEL: [phone], FAX: [phone]

<BELGIUM>

NAME: General Audio
ADD: Raymond Pelgrimslaan 101, B-1702 Groot­Bijgaarden, Belgium
TEL: [phone], FAX: [phone]

<DENMARK>

NAME: SC Sound ApS
ADD: Malervej 2, DK-2630 Taastrup, Denmark
TEL: [phone], FAX: [phone]

<FINLAND>

NAME: Noretron Oy Audio
ADD: P. O. Box 22, FIN-02631 Espoo, Finland
TEL: [phone], FAX: [phone]

<FRANCE>

NAME: Sennheiser France
ADD: 128 bis, avenue Jean-Jaures, 94851 Ivry-sur-Seine
Cedex, France
TEL: [phone], FAX: [phone]

<GERMANY>

NAME: Mega Audio GmbH
ADD: Stromberger Str. 32, D-55411 Bingen, Germany
TEL: [phone], FAX: [phone]

<GREECE>

NAME: Bon Studio S. A.
ADD: 6 Zaimi Street, Exarchia, 106.83 Athens, Greece
TEL: [phone], 606, 607, 608
FAX: [phone]

<ICELAND>

NAME: I. D. elrf. electronic Ltd.
ADD: ARMULA 38 108 REYKJAVIK, ICELAND
TEL: [phone], FAX: [phone]

<ITALY>

NAME: Proel S. p. A.
ADD: Zona Via Alla Ruenia, 37/43 64027 - Sant'Omero
(Teramo), Italy
TEL: [phone], FAX: [phone]

<THE NETHERLANDS>

NAME: IEMKE ROOS AUDIO B. V.
ADD: Kuiperbergweg 20, 1101 AG Amsterdam, The
Netherlands
TEL: [phone], FAX: [phone]

<NORWAY>

NAME: Siv. Ing. Benum AS
ADD: P.O. Box 145, Vinderen, 0319 Oslo, Norway
TEL: [phone], FAX: [phone]

<PORTUGAL>

NAME: Caius - Tecnologias Audio e Musica, Lda.
ADD: Praca do Bom Sucesso, No 61 Bom Sucesso Trade
Center, Escritorio 701/702, 4150-1460 Porto, Portugal
TEL: [phone], FAX: [phone]

<SPAIN>

NAME: Letusa S. A.
ADD: C/Laguna 10, 28923 Alcorcon, Madrid, Spain
TEL: [phone]
FAX: [phone]

<SWEDEN>

NAME: Sennheiser AB
ADD: John Ericssonsgatan 10, P.O. Box 22035, SE-104 22
Stockholm, Sweden
TEL: [phone], FAX: [phone]

<SWITZERLAND>

NAME: Audio Bauer Pro AG
ADD: Bernerstrasse-Nord 182, CH-8064 Zurich, Switzerland
TEL: [phone], FAX: [phone]

<UK>

NAME: SCV London
ADD: 40 Chigwell Lane, Oakwood Hill Industrial Estate,
Loughton, Essex IG10 3NY U. K.
TEL: [phone], FAX: [phone]

FOSTEX CO.

3-2-35, Musashino, Akishima-shi, Tokyo, Japan 196-0021

FOSTEX AMERICA

13701, Cimarron Avenue, Gardena, CA 90249, U. S. A.

9

© PRINTED IN CHINA AUGUST 2005 432656