KRK KRK12s User manual
KRK12sSUBVVOOFER
USER
GUIDE
GUIDE
D'UTILISATION
GUiA
DE
USUARIO
Instruction
Manual
(English)-
Page
1
Manuel
d'instruction
(fran~ais)-
Page
28
Manual
de
instrucciones
(espanol)-
pagina
56
1
IMPORTANT
SAFETY
INSTRUCTIONS
~
CAUTION:
THE
LIGHTNING
FLASH
WITH
AN
ARROWHEAD
SYMB
OL
WITHIN
AN
EQUI
L
ATERA
L
TRIANGLE
IS
INTENDED
TO
ALERT
THE
~USER
TO
THE
PRESENCE
OF
UN-INSULATED
DANGEROUS
VOLTAGE
WITHIN
THE
UNITS
E
NC
LOSURE
T
HAT
MAY
BE
OF
SUF
F
IC
IENT
MAGNITUDE
TO
CONSTITUTE
A
RISK
OF
ELECTRIC
SHOCK
TO
PERSONS.
f:\
WARNING
:
THE
EXCLAMATION
POINT
WITHIN
AN
EQU
I
LATERAL
TRIANGLE
ISIN
TENDED
TO
ALERT
THE
U
SER
TO
TH
E
PRESENC
E
OF
~IMPORTANT
OPERATING
AND
MAINTENANCE
(SERVICING)
INSTRUCTIONS
IN
TH
E
LITERATURE
ACCOMPANYING
THE
PRODUCT.
~
NOTE:
THE
HAND
WITHIN
AN
EQUILATERAL
TRIANGLE
IS
INTENDED
TO
ALERT
THE
USER
TO
SPECIFIC
GUI
DANC
E
AND
IN
F
ORMAT
I
ON
~REGARDING
THE
OPERATION
OF
THE
UNIT
,
AND
SHOULD
BE
READ
FUL
LY
BEFO
RE
US
I
NG
THE
UNI
T
FO
R
THE
FIR
ST
T
IME
.
CAUTION
RISK
OF
ELECTRIC SHOCK
DO
NOT
OPEN
ATTENTION
RISQUE DE CHOC ELECTRIQUE
NE
PAS OUVRIR
~
CAUTION:
TO
REDUCE
THE
RISKS
OF
FIRE
OR
ELECTRIC
SHOCK
DO
NOT
REMOVE
ANY
COVERS,
OR
OPEN
THE
UNIT.
THERE
~ARE
NO
USER-SERVICABLE
PARTS
INSIDE.
ALL
SERVICING
SHOULD
BE
REFERRED
TO
QUALIFIED
SERVICE
ENGINEERS.
f:\
WARNING:
READ
AND
FOLLOW
ALL
THE
SAFETY
AND
OPERATING
INSTRUCTIONS
BEFORE
CONNECTING
OR
USING
THIS
~UNIT.
RETAIN
THIS
USER
MANUAL
FOR
FUTURE
REFERENCE.
ALL
WARNINGS
ON
THE
UNIT
AND
ITS
PACKAGING
SHOULD
BE
READ
AND
FOLLOWED.
1:\
WARNING:
This
product
contains
a
chemical
known
to
the
State
of
California
to
cause
cancer
and
birth
de
fe
ct
s
or
o
ther
reproductive
~harm.
~
CAUTION:
To
reduce
the
risks
of
fire
or
electric
shock
do
not
expose
thi
spr
oduct
tora
in
or
mois
ture.
Do
no
t u
se
this
pr
oduct
near
~
wa
ter;
for
example,
near
a
bath
tub
,
washbowl,
k
itchen
sink,
lau
n
dry
tu
b,
in
a
wet
ba
se
me
nt
or
near
a
sw
immin
g
pool.
Unplu
g
th
e
unit
from
the
wall
outlet
before
cleaning.
N
eve
r
use
th
inner
,
cleaning
fluids
,
so
lven
ts
or
chemically
imp
r
eg
n
ated
clo
ths.
For
cl
ean
i
ng
always
use
a
soft
dry
cloth
.
Unplug
this
product
during
lightning
s
torms
or
when
unus
edf
or
long
periods
of
time
.
~
CAUTION
:
The
unit
should
be
installed
so
that
its
location
or
position
do
es
not
interfere
with
its
proper
ven
ti
latio
n.
For
example
,it
~should
not
be
situated
on
a
bed
, s
ofa
,
rug
or
si
milar
sur
face
that
may
b
lo
ck
the
ventilation
openings;
or
placed
inabuilt-in
installation
,
such
as
a
bookca
se
or
cabinet,
that
may
imped
e
the
flow
of
air
through
its
ventilatio
n
ope
n
ing
s.T
he
unit
sho
uld
be
situated
from
heat
sources
such
as
radiators,
heat
re
giste
rs,
stoves
or
other
devices
(i
n
cl
uding
amplifiers)
that
produce
h
ea
t.
No
naked
flame
so
urce
s,
such
as
lighted
candles,
s
hould
be
placed
on
,
or
ne
ar
the
unit.
1:\
WARNING:
Do
not
place
th
is
unit
on
an
unstable
s
urfa
ce,
cart,
stand
or
tripod
,
bra
cke
t
or
tab
le.
The
unit m
ay
fal
l,
cau
si
ng
serious
~injury
to
a
child
or
adult
and
serious
damage
to
the
unit.
Use
only
wi
th
a
ca
rt
,
stand,
tr
ipo
d,
bracket
or
table
r
ecommended
by
t
he
manufacturer
or
so
ld
w
ith
the
unit.
Any
mounting
of
t
he
devi
ce
on
a
wal
l
or
ce
iling
should
fo
llow
th
e
ma
nufa
ct
ur
er's
in
s
tru
ct
io
ns
and
should
use
a
mounting
accessor
y
recommend
ed
by
t
he
manuf
act
urer.
An
app
l
iance
and
cart
combi
n
at
io
nsh
oul
d
be
moved
w
ith
care.
Quick
s
tops
,
excessive
for
ce
and
uneven
s
urface
s
ma
y
cause
th
e
appliance
and
ca
rt
combi
n
at
io
n
to
overturn.
U
se
only
with
the
c
art
,
st
and
,
tripod
,
bracket,
or
table
sp
ec
ified
by
the
manuf
act
ur
er,or
so
ld
w
ith
t
he
apparatus.
When
a
cart
is
used
,
use
caution
w
hen
moving
th
e
ca
rt
/appa
ratus
co
mbinati
on
to
avoid
in
jur
y
from
t
ip
-ove
r.
~
NOTE
:
Should
the
unit
becom
e
damaged
beyond
repair
,
or
reaches
t
he
end
of
its
life,
please
co
ns
ult
t
he
regulations
r
ega
r
ding
~disposal
of
electronic
product
s
in
your
region.
~
NOTE:
KRK
Systems,
LLC
cannot
be
held
respon
s
ible
for
damage
,
and
,or
including
data
loss
caused
by
imp
rope
r
use
of
th
e
unit
and
~or
the
applications
provided
for
u
se
w
ith
the
unit.
2
IMPORTANT
SAFETY
INSTRUCTIONS
11_
CAUTION
TO
PREVENT
ELEORIC
SHOCK,
MATCH
WIDE
BLADE
OF
PLUG
TO
WIDE
SLOT
FULLY
INSERT.
~ENGLISH:
The
apparatus
shall
be
connected
to
a
Mains
socket
outlet
w
ith
a
protective
earthi
ng
co
nne
ction
.
GERMAN:
Das
Gerat
ist
eine
Wandsteckdose
mit
einem
Erdung
s
leiter
angeschlossen
werden.
FRENCH:
L'
appareil
do
it
etre
connecte
a
une
prise
secteur
avec
connexion
a
Ia
terre.
SPANISH:
El
aparato
estara
conectado
a
una
tom
a
de
red
electrica
con
una
conexi6n
a
tierra.
ITALIAN:
L'apparecchio
deve
essere
collegato
a
una
presa
di
rete
con
una
connessione
a
terra
protettiva.
'L
2
1..
The
unit
and
power
supply
should
only
be
connected
to
a
powe
r
supply
outlet
only
of
the
voltage
and
fre
que
ncy
ma
r
ked
on
~
its
casing.
Protect
the
power
cable
from
being
walked
on
or
pinched
particularly
at
plugs,
convenience
receptac
l
es,
and
the
point
w
her
e
they
exit
from
the
apparatus.
3.
Do
not
defeat
the
safety
purpose
of
the
polarized
or
grounding-type
plug.
A
pola
r
iz
ed
plug
has
twob
lades
wi
th
one
wider
than
the
other.
A
grounding
type
plug
has
two
blades
anda
third
grounding
prong.
The
wide
bl
ade
or
the
third
prong
is
provided
for
your
safety.
If
the
provided
plug
does
not
fit
into
your
outlet,
consu
lt a
qualified
electrician
for
re
placement
of
the
obsolete
outlet.
4.
If
the
mains
plug
supplying
this
product
incorporates
a
fuse
then
it
should
only
be
replaced
w
ith
a
fuse
of
ide
nt
i
ca
l
or
lo
we
r
rupture
value.
5.
Never
use
a
damaged
or
frayed
power
cable;
thi
s
can
introduce
serious
ri
sk
of
exposing
le
t
hal
voltages.
6.
The
power
supply
cable
of
the
unit
should
be
unplugged
from
the
wall
outlet
when
it
is
to
be
unu
s
ed
for
a
long
peri
od
of
time.
7.
Only
use
attachments
/
accessories
s
pecified
by
the
manufacturer.
11_
DO
NOT
ATTEMPT
SERVICING
OF
THIS
UNITVOURSELF
.
REFER
SERVICING
TO
QUALIFIED
SERVICE
PERSONNEL.
~Upon
completion
of
any
servicing
or
repairs,
request
the
assurance
that
only
Factory
Authorized
Re
pla
ce
me
nt
P
ar
ts
wi
tht
he
same
characteristics
as
the
original
parts
have
been
used,
and
that
the
routine
safety
checks
have
been
performed
to
gua
ra
ntee
that
the
equipment
is
in
safe
operating
condition.
11_
REPLACEMENT
WITH
UNAUTHORIZED
PARTS
MAY
RESULT
IN
FIRE
,
ELEGRIC
SHOCK
OR
OTHER
HAZARDS.
~ATTENTION
POUR
...
VITER
LES
CHOC
ELEGRIQUES,
INTRODUIRE
LA
LAME
LA
PLUS
LARGE
DE
LA
FICHE
DANS
LA
BORNE
CORRESPONDANTE
DE
LA
PRISE
ET
POUSSER
JUSQUIAU
FOND.
11_
This
unit
should
be
serviced
by
qualified
service
personnel
when:
~The
power
cord
or
the
plug
has
been
damaged
Objects
have
fallen,
or
liquid
ha
s
been
spilled
into
the
unit
The
unit
has
been
ex
posed
to
rain
or
liquids
of
any
kind
The
unit
does
not
appear
to
operate
normall
y
or
exhibits
a
marked
c
hange
in
performan
ce
The
device
has
been
dropped
or
the
enclosure
damaged.
~
NOTE:
Unplug
the
unit
from
the
wall
outlet
before
cleaning.
Never
use
be
nzene
,th
inner
or
other
solvents
for
clea
n
ing.
Use
on
lya
~oft
damp
cloth.
~
NOTE:
Care
should
be
taken
so
that
objects
do
not
fal
l,
and
liquids
are
not
sp
illed
into
the
enclosure
through
any
ope
ning
s.
~If
an
indoor
antenna
is
us
ed
(
either
built
into
the
set
or
in
st
alled
separately
),
never
allow
any
p
art
of
the
ante
n
na
tot
ouch
the
meta
l
parts
of
other
electrical
appliances
s
uch
as
a
lamp
,
TV
set
etc.
/A
CAUTION-
POWER
LINES
Any
outdoor
antenna
must
be
located
away
from
all
power
l
in
es
.
3
IMPORTANT
SAFETY
INSTRUCTIONS
~
OUTDOOR
ANTENNA
GROUNDING
If
an
outside
antenna
is
connected
to
your
tu
n
er
or
tuner-preamplifier
,
be
sure
the
antenna
~system
is
grounded
so
as
to
provide
some
protection
against
voltage
surges
and
built-up
static
charges.
Art
i
cle
810
of
t
he
Nat
i
onal
Electrical
Code,
ANSI
/
NFPA
No
.
70-1984,
provides
information
with
respect
to
proper
ground
i
ng
of
the
mast
and
s
upporting
structure,
grounding
of
the
lead-in
wire
to
an
ant
e
nna
di
s
charge
unit
,
size
of
grounding
conductors
,
location
of
antenna
di
scharge
unit
,
connection
to
grounding
electrodes
and
requirements
for
the
grounding
electrode.
a.
Use
No.
10
AWG
(5.3mm
2)
copper,
No.8
AWG
(
8.4mm
2)
aluminum
,
No.
17
AWG
(1
.0
mm2)
copper-
c
lad
steel
or
bronze
w
ire
,
or
larger
,
as
a
ground
wire.
b.
Secure
antenna
lead-in
and
ground
wires
to
house
with
stand-off
i
nsulators
s
pa
ce
d
from
4-6
fee
t (
1.22
-1.83
m)
ap
a
rt.
c.
Mount
antenna
discharge
unit
as
close
as
possible
to
where
lead-in
enter
s
house
.
d.
Use
jumper
wire
not
smaller
than
No.6
AWG
(13.3mm
2)
copper
,
or
the
equivalent,
wh
en
a
separate
antenna-grounding
e
le
ctro
de
is
used.
see
NEC
Section
810-21
OJ.
EXAMPLE
OF
ANTENNA
GROUNDING
AS
PER
NATIONAL
ELECTRICAL
CODE
I
NS
TRUCTIO
NS
CONTAINED
IN
ARTICLE
810-
RAD
IO
AND
TELEVISION
EQUIPMENT.
ANTt;NNA
LEAD-INWIRE
;<I
POWER SERVICE
GROUNDIN~
_
,.__y
_,
, '·
~L!~~~~~~~.~~i~o
r
pipe) BONDING JUMPERd
~~~EU~~
~fiJ~:
NAL
TERMINALS
OF PRODUCT
..
OPTIONALANTENNA GROUND-
ING ELECTRODE.
DRIVEN 8 FEET (2.44
1.1}
INTO
THE EARTH
IF
REQUIRED
BV
L
OC
AL
CODES. SEE
NE
C
SECTION 810.
21
(1)
.
NOTE
TO
CATV
SYSTEM
INSTALLER:
This
reminder
is
provided
to
call
the
CATV
sys
tem
in
st
aller
satte
nt
i
on
to
Article
820-40
of
the
National
Electrical
Code
that
provides
guidelines
for
proper
grounding
and,
in
part
i
cular
,
specifies
that
t
he
gr
o
und
cable
ground
sh
all
be
connected
to
the
grounding
system
of
the
building
,
as
close
to
the
point
of
cab
le
entry
as
pr
acti
ca
l.
REGULATORY
CERTIFICATION
KRK
declare
under
our
sole
respon
s
ibility
that
this
product
,
to
w
hich
th
is
declaration
relates
,
is
in
conform
itywi
th th
efo
llo
wi
ng
standards:
CE
!
REACh
The
Declarations
of
Conformity
can
be
obtained
from
382
Ave
.
de
Ia
Couronne,
B-1050
Brussles
Authorized
European
representati
v
e:
Phone:
+3226450500
Fax:
+326450505
4
World
Class
Performance
in
Studio
Reference
Monitors
KRK
's
industry-leading
line
of
studio
monitors
and
subwoofers
provide
a
level
of
precision
and
performance
unheard
of
in
monitor
systems.
Your
KRK12s
subwoofer
features
several
key
design
elements
that
have
come
to
be
recognized
as
the
"
studio
standard
"
for
the
world's
finest
engineers,
producers
,
and
musicians
.
Your
KRK
subwoofer
delivers
world-class
performance-
at
a
price
that
makes
this
a
truly
uncommon
value
.
Contents
Introduction
Unpacking
KRK
System
s'
Design
Philosophies
KRK
's
ERGO
Room
Correction
System
System
Controls-
Rear
Panel
Connecting
Your
System
Subwoofer
Placement
and
Set
Up
Hooking
Up
Your
Subwoofer:
5.1
Surround
Bass
Management
Theory
Removing
the
Subwoofer
Grill
Troubleshooting
Shipping
Instructions
Specifications
5
6
7
8
10
13
15
17
19
20
21
25
27
5
Introduction
Congratulations
and
thank
you
for
purchasing
the
KRK12s
active
studio
subwoofer!
We
are
the
most
dedicated
monitor
company
in
the
world
and
we
are
thrilled
you
have
joined
our
ever
growing
family
of
loyal
customers.
The
KRK12s
joins
our
premium
subwoofer
series,
delivering
an
outstanding
performance,
incredible
accuracy
,
and
high
output
level,
again
raising
the
bar
above
the
competition.
We
are
not
the
new
standard.
We
have
always
been
the
standard
among
the
world's
finest
engineers,
producers,
musicians,
and
DJs.
The
purpose
of
this
manual
is
to
explain
the
main
features
of
the
KRK12s
and
briefly
describe
its
operation
.
We
encourage
you
to
take
a
few
minutes
to
familiarize
yourself
with
the
included
information.
Thank
you
for
choosing
KRK!
Important
notes:
Safety:
To
ensure
correct
operation
of
this
product
and
for
your
own
safety
,
please
read
the
Important
Safety
Instructions
section
.
Caution:
Do
not
remove
the
rear
panel
of
the
subwoofer.
It
could
result
in
electric
shock.
Refer
to
qualified
service
personnel
to
perform
any
repair
or
service
to
the
electronics.
This
product
is
capable
of
producing
sounds
at
a
volume
that
could
cause
permanent
hearing
damage.
6
•
x
•
•
7
KRK
Systems'
Design
Philosophies
Our
Focus
is
Your
Mix
At
KRK,
our
focus
has
always
been
to
make
the
most
accurate
studio
monitors
available
at
any
price
.
We
don't
offer
PA
gear,
mixers
or
motorcycles-
just
the
tools
you
need
to
deliver
a
great
mix
.
From
the
legendary
Expose
Series
,
to
VXT
to
the
new
RoKit
Generation
2
("
G2")
series
-
we
know
recording
monitors.
We
do
not
add
so
nic
characteristics
like
some
other
manufacturers
that
make
their
monitors
appear
to
provide
more
SPL
or
add
low
frequencies
which
may
sound
impressive
to
an
untrained
ear
,
but
prevent
a
competent
engineer
from
making
the
right
mix
deci
s
ions
.
When
you
use
a
KRK
monitor,
you
can
be
confident
that
your
mixes
will
tran
s
late
well
to
the
wide
variety
of
playba
ck
condition
s
that
c
an
oc
c
ur
in
the
real
world.
We
want
your
audio
mixes
to
s
ound
good
everywhere-
not
just
in
your
studio!
Port
Design
Our
port
s
are
designed
to
greatly
reduce
air
flow
turbulence
for
high
performance
audio
reproduction.
The
result?
Clear,
accurate
and
well
designed
low
frequency
exten
s
ion
.
Even
More
Accurate
than
Before
We
optimized
our
s
peaker
voicing
to
provide
even
more
accurate
frequency
response
for
transparent
audio
reproduction
using
our
custom
made
KRK
drivers
.
What
you
hear
is
what
you
get
,
where
ever
your
music
is
being
played.
Our
drivers
are
all
cu
s
tom-designed
by
our
world-class
studio
monitor
engineering
team.
8
KRK's
ERGO
Room
Correction
System
~=~!;§~g
=
..
=(1)/Ff..wtfl
=lllllrm.
~PERFECT
We
highly
recommend
use
of
the
KRK
ERGO
room
correction
I
audio
interface
for
delivering
the
best
po
s
sible
performance
from
your
KRK
monitoring
sy
s
tem
.
ERGO
is
a
standalone,
high-performance
room
correction
system
that
allow
s
you
to
use
up
to
two
subwoofers
with
dedicated
crossover
functionality
and
delay
compensation,
and
act
as
FireWire
audio
interface
with
s
uperb
quality
c
onversion
.
For
more
information
about
using
ERGO
with
your
monitoring
system,
please
visit
our
website
at
http:/
/
www
.
krksys.com
/
product_
ergo
.
ph
p
9
LINE
INPUTS
LEFT
RIGHT
HIGH
PASS
FILTER
LOW
PASS
FI
LT
ER
LFE
+lOdB
FOOTS
WI
T
CH
I
BYPASS
LINE
OUTPUTS
LE
FT
v
RIGHT
~
MONO
SUM
SUBSONIC
VOL
UME
LIMITER
POLARITY
FI
LTER
LF
OUTPUT
10
System
Controls-
Rear
Panel
Be
f
ore
i
ns
ta
lli
ngand
connect
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ng
the
K
RK12s
, pl
ease
read
the
System
Con
tr
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cr
ipti
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youare
famili
ar
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the
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Figure
2.1
-
System
Controls
on
the
Rear
Panel
11
(1)
RIGHT
&
LEFT
INPUTS-
BALANCED
The
RIGHT
&
LEFT
inputs
should
be
connected
to
the
mixer
or
source
outputs
.
(2)
RIGHT
&
LEFT
OUTPUTS-
BALANCED
The
RIGHT
&
LEFT
outputs
should
be
connected
to
the
studio
monitors.
The
subwoofer
outputs
have
an
80
Hz
HPF
(high
pass
filter)
that
removes
low
frequency
sound
and
passes
only
the
mid
and
high
frequency
to
the
studio
monitors.
(3)
SUB/HP
FILTER
BYPASS(FOOTSWITCH)
The
by-pass
feature
allows
you
to
defeat
(bypass}
the
subwoofer
and
provide
full
range
audio
to
your
studio
monitors
in
instances
where
the
RIGHT
&
LEFT
outputs
are
being
utilized.
When
the
switch
is
activated,
the
high
pass
filter
in
the
subwoofer
will
be
by-passed
allowing
full
bandwidth
sound
to
the
studio
monitor.
The
su
bwoofer
will
al
so
mute
allowing
an
evaluation
on
the
impact
of
the
subwoofer
in
the
studio.
The
foot
switch
can
be
activated
by
a
standard
male
W',
mono,
latching
footswitch
to
the
female
W'
connector
on
the
back
panel
(see
footswitch
model
KRK
KFS-1).
Please
note
that
the
KRK12s
does
not
support
the
LED
indicator
feature
on
the
footswitch
model
KRK
KFS-1.
(4)
LFE
INPUT
The
LFE
in
put
is
TRS
balanced.
The
LFE
(low-Frequency
Effects/Enhancement)
input
is
intended
for
a
surround
system
with
a
channel
dedicated
to
low
frequency
sounds
ranging
from
3Hz
to
120Hz.
(5)
LIMITER
The
subwoofer
contains
a
limiter
circuit
which
provides
improved
protection
.
The
default
setting
for
this
switch
will
be
in
the
OFF
position.
The
limiter
is
designed
to
mitigate
the
negative
effects
of
over
driving
the
amplifier
and
ore
the
speaker
's
drivers.
The
limiter,
when
engaged
to
the
ON
position,
can
greatly
reduce
the
risk
of
harming
a
driver.
(6)
POLARITY
Functionally,
the
Polarity
switch
is
a
polarity
inversion
mechanism
whose
position
affects
the
phase
relation
of
the
subwoofer
output
to
the
other
speakers
in
your
room
.
The
proper
switch
position
of
0
or
180
degrees
depends
on
a
number
of
variables.
These
variables
include,
the
distance
of
the
subwoofer
from
the
listening
position
and
monitors,
as
well
as
the
system's
absolute
polarity
and
the
bass
response
of
the
room
(refer
to
the
Subwoofer
Setup
and
Placement
section
in
order
to
determine
the
correct
switch
position
for
your
monitoring
system
and
room}
.
The
KRK12s
is
shipped
with
the
polarity
switch
set
to
0
degrees.
(7)VOLUME
The
volume
control
adjusts
the
input
sensitivity
(counterclockwise
reduces
sensitivity).
The
volume
range
is
from
-30
dB
to+
18
dB
and
the
KRK12s
is
shipped
at
the
-30dB
setting.
Adjustment
to
the
volume
may
need
to
be
made
to
match
the
level
of
the
studio
monitors.
12
(8)
LOW-PASS
FREQUENCY
The
low-pass
frequency
adjustment
is
performed
through
a
continuously
variable
adjustment.
The
range
is
from
55
Hz
to
170Hz.
If
you
are
using
the
Subwoofer
RIGHT
&
LEFT
outputs
to
a
set
of
studio
monitors,
than
place
this
adjustment
at
the
80Hz
position
.
The
KRK12s
is
shipped
at
the
80Hz
setting
.
(9)
GROUND
LIFT
Engaging
the
ground
lift
switch
can
sometimes
reduce
ground
loop
noise
in
your
system.
By
providing
an
AC
mains
ground
on
the
KRK12s
and
proper
installation
in
a'
quiet
studio'
environment,
the
system
is
happily
quiet.
However,
noise
will
be
induced
if
the
monitor
is
installed
in
less
than
desirable
settings
(i.e.
audio
cables
run
alongside
power
cables
,
behind
refrigerators
,
near
florescent
lighting,
older
buildings
with
bad
wiring)
,
or
with
certain
equipment
with
lots
of
RFI
(lap-top
supplies,
PCs
,
generator
supplied
AC
lines).
This
is
because
there
is
a
ground
loop
through
the
sub
panel
,
mains
wiring
,
source,
and
back
to
the
subwoofer
on
Pin-1
of
the
Audio
inputs.
Ground
currents
traveling
through
this
loop
impose
different
voltages
along
the
path
at
different
gain
stages
within
the
circuitry,
thus
creating
noises
.
The
ground
lift
switch
does
not
affect
the
AC
mains/panel
safety
ground
.
It
does
not
'
open'
the
connection
thru
Pin-1
to
the
panel,
but
increases
the
resistance
(from
zero
ohms
to
one
thousand
ohms)
to
reduce
the
ground
current
and
induced
noises.
Safety
is
not
affected.
The
KRK12s
is
shipped
with
the
ground
lift
switch
set
to
GND
(10)
UNBALANCED
LINE
IN
&
LINE
OUT
The
RCA-type
line
in
and
line
out
are
unbalanced,
which
is
typically
used
for
home
audio
systems
.
The
outputs
have
an
80Hz
HPF
(high
pass
filter)
that
removes
low
frequency
sound
and
passes
only
the
mid
and
high
frequency
to
the
studio
monitors
.
(11)
POWER
SWITCH
The
power
On/Off
switch
is
located
on
the
rear
panel.
The
triangle
in
the
KRK
logo
on
the
rear
plate
illuminates
when
power
is
applied
.
Upon
initial
turn-on,
the
triangle
in
the
KRK
logo
will
briefly
turn
red
and
then
change
to
yellow
which
indicates
the
su
bwoofer
is
ready
to
be
used
.
The
s
ubwoofer
is
in
a
fault
condition
when
the
triangle
in
the
KRK
logo
is
always
red.
This
may
indicate
a
faulty
driver
or
power
supply
failure.
(12)
AC
INPUT
VOLTAGE
SELECTOR
To
change
the
AC
Input
Voltage,
remove
the
power
cord
and
slide
the
voltage
selector
to
the
desired
voltage
setting.
Please
note
that
when
making
voltage
changes,
the
fuses
will
have
to
be
replaced
(refer
to
the
Changing
Fuses
section
below).
(13)
AC
INPUT
INLET
SOCKET
A
standard
IEC-type
AC
Inlet
Socket
is
used
to
provide
power
to
the
subwoofer.
Be
sure
to
use
the
power
cord
that
is
included
with
the
product
or
one
that
is
rated
equal
or
greater
than
240V,
15A.
13
(14)
FUSE
HOLDER
Under
normal
operation
the
fu
s
es
should
not
blow.
A
blown
fu
se
usually
indicates
an
overl
o
ad
or
fault
condition.
To
change
the
fuse,
remove
the
power
cord,
pry
off
the
fu
se
block
with
a
small
flathead
screwdriver
and
change
the
blown
fuse
s.
Refer
to
the
Specifications
section
for
fuse
current
ratings.
NOTE:
If
the
fus
es
blow
immediately
upon
power
up
,
this
indicates
a
fault
condition
and
the
monitor
sh
o
uld
be
returned
to
KRK
for
repair.
Connecting
Your
System
IMPORTANT
:
Before
starting
up
the
subwoofer,
be
sure
all
connections
are
made,
all
fader
and
controls
should
be
set
at
their
minimum
levels,
and
all
other
equipment
should
be
powered
prior
to
powering
up
your
KRK12s
subwoofer
. If
you
are
connecting
the
sub's
Line
Outs
to
your
monitors,
turn
monitor
power
on
after
the
subwoofer.
KRK
subwoofer
s
include
a
built-in
crossover
and
amplifier,
so
youo
nly
need
the
appropriate
hook
up
cable
s
to
integrate
it
into
your
exi
s
ting
monitor
s
ystem
.
First,
you'll
need
to
c
onnect
a
pair
of
cables
from
the
stereo
monitor
o
utputs
of
your
cons
o
le
(
or
audio
hardware
device
)
to
the
left
and
right
XLR
or
W'
input
jacks
on
the
subwoofer.
Next,
if
you
are
using
the
internal
80
Hz
high-pass
filter
built
into
the
subwoofer
for
the
existing
full-range
monitors,
hook
the
XLR
output
jacks
on
the
subwoofer
to
the
line-
level
inputs
of
your
full
range
monitors
.
A
more
advance
system
is
required
if
th
e
preferen
ceis
to
not
use
the
internal
80Hz
high-pa
ss
filter.
Such
advance
systems
would
require
the
use
of
an
external
cro
ss
over.
It
is
recommend
ed
to
use
an
ex
t
ernal
crossover
that
feature
sa
subwoofer
output
connection.
Consult
the
external
crossover
user
manual
to
learn
how
to
setup
and
connect
the
full
range
monitors
and
a
subwoofer.
14
Subwoofer
Hook
Up
with
Artive
Monitors
If
yo
uare
using
ac
t
ive
(powered)
monitors,
use
an
XLR
or
W'
c
ab
leto
connect
the
output
of
the
subwoofe
r
di
rec
tly
to
the
input
of
the
mon
i
tor.
Theou
tput
marked
"Left
"
should
go
to
you
rl
eft
mon
i
tor,
and
the
ou
tput
marked
"
Right"
sh
ou
ld
go
to
your
rightm
on
i
tor.
000
0
000
0
0
00
00
0 0
000
00
00
000
00
00
0000000
H
HH
iiii
0 0 0
0
hJ.
=--
0 -
·-
Figure
3.1
-
Subwoofer
Hookup
with
A(tive
Studio
Monitors
Subwoofer
Hook
Up
with
Passive
Monitors
@ @
f
fi
nilll
I
.,
I"'!!!"
"!
!"'
I J
IW,-j
If
you
are
usi
ng
pass
i
ve
(n
on-powered)
mo
n
itors,
use
an
XLRorW'
cab
le
to
connec
t the
outpu
t
of
the
subwoofer
directly
to
thein
put
of
the
mon
it
or
's
externa
l
power
ampl
ifier,
and
then
co
n
nect
the
power
amp
l
if
i
er
spea
k
er
o
ut
put
to
the
mon
i
tors.
Do
n
ot
connect
t
he
speaker
output
oft
he
monitor's
externa
l
amp
lifi
er
tothe
in
put
of
the
subwoofe
r.
Th
is
will
ca
u
se
pe
r
ma
n
ent
da
m
age.
0 0 0
0
~""!
-
00000000
-<(!)
.
0000000
0
0000000
0000000
-.;;...-
0000000
¥ 0 0 0
0000000
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="'
i
tt
it
if
~~~
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. o
c::::J
o
Figure
3.2
-
Subwoofer
Hookup
with
Pa
s
sive
Stud
io
Monito
rs
15
-
-
-
-
Subwoofer
Placement
and
Set
Up
The
basics
of
subwoofer
placement
It
is
widely
accepted
that
frequencies
below
100Hz
are
generally
om
ni-di
r
ec
ti
on
al,
which
is
to
say
it
is
almost
i
mposs
ible
to
detect
where
they
are
originat
i
ng
fro
minaa
ny
given
sp
a
ce
.
Wh
at
is
l
ess
co
mm
only
kn
own
is
th
at
the
geometry
of
and
objects
within
ar
oom
ca
n
gre
atl
y
affect
h
ow
the
subwoofer
will
react.
Here
are
so
me
su
g
ges
ti
ons
ofthi
ng
s
to
kee
pin
mi
nd
for
pr
ope
r
subwoo
fer
pl
a
ce
m
en
t.
Keep
the
subwoofer
as
near
asis
practica
l
to
the
satel
l
ite
speakers.
Th
is
wi
ll
r
educe
po
ss
ible
in
terferen
ce
from
time
alignment
i
ssues.
Keep
th
esu
bwoofe
r
aw
ay
fr
om
corners
and
walls
if
possi
b
le.
W
hi
le
th
e
effects
of
p
rox
imi
ty
to
solid
s
ur
faces
ca
n
be
overco
me,
it
is
ofte
n
best
to
avoid
th
ose
situations
completely
if
po
ssi
bl
e.
One
of
the
eas
i
est
ways
to
determine
the
ideal
placement
of
a
subwoofer
is
to
st
a
rt
wi
th
t
he
su
bw
oo
fer
in
th
em
ai
n
li
ste
ni
ng
position
and
move
yourself
around
the
room
. Where
th
eba
ss
sou
n
ds
smoothest
,
or
eve
n
loudest
,is
usually
ag
oo
dspotto
start
with
pl
aci
ngt
he
subwoo
fer.
On
ce
you
have
th
e
su
b
woofer
inapl
ace
whereit
ma
k
es
s
ense,
sitin
the
main
lis
te
ni
ng
pos
iti
on
and
listen
for
the
bass
response.
Move
the
subwoofer
around
by
about
a
foot
at
at
im
e
unt
il
you
find
the
place
where
the
l
ow
end
sounds
the
smoo
th
est.
Su
b
woo
fer
,'
'
'
'
Focu
sI
Li
ste
n
in
g
Po
si
tion
Figure
4.0-
Subwoofer
Placement
16
-
-
-
-
-
-
Subwoofer
volume
and
phase
alignment
The
next
step
is
to
configure
the
subwoofer
volume
and
phase
settings
for
your
system.
Here
are
some
step
by
step
instructions
for
how
to
do
this.
Start
with
your
subwoofer
crossover
set
to
around
80Hz.
Next,
route
a
band
limited
pink
noise
tone
through
the
system
including
the
satellite
speakers.
SOOHz-1
kHz
will
allow
you
to
set
the
volume
of
the
satellites
without
exciting
the
subwoofer.
Using
an
SPL
meter
(or
iPhone
app),
set
the
overall
volume
so
that
the
level
is
something
comfortable.
Around
85dB
should
suffice.
Run
another
band
limited
pink
noise
tone
of
35Hz-70Hz
through
the
system
and
set
the
volume
on
the
sub
to
where
it's
hitting
85dB
on
the
meter
as
well.
Set
the
low
pass
crossover
to
the
highest
setting
(near
130Hz).
Run
a
band
limited
pink
noise
tone
from
60Hz-120Hz
and
from
the
listening
position,
determine
if
0
or
180
on
the
phase
switch
is
loudest.
Leave
the
switch
in
the
loudest
position.
If
your
subwoofer
has
a
variable
phase
knob,
run
a
70Hz
test
tone
through
the
system.
Flip
the
phase
switch
to
either
180
or
0,
whatever
the
opposite
of
what
it
was
in
the
previous
step,
and
adjust
the
variable
phase
until
the
bass
level
is
quietest.
Then
flip
the
pha
se
switch
back
to
0.
Finally
listen
to
some
music
you
are
familiar
with
and
set
the
crossover
level
to
a
place
where
you
only
hear
low
end
and
no
mid
frequencies
coming
from
the
sub.
A
commonly
accepted
practice
is
to
double
the
lowest
frequency
that
the
satellite
speakers
are
rated
for
and
use
that
as
the
crossover
frequency
.
17
Hooking
Up
Your
Subwoofer:
S.
1
Surround
Thi
sisabit m
ore
in
volved
than
a
stereo
hook
up
since
there
are
now
six
speake
rs
i
nvo
l
ve
d-
as
we
ll
as
something
ca
ll
ed
Bass
Management
(see
the
Bass
Management
Theory
sedion).
Notice
in
th
e
figure
below
th
at
for
professional
use
a
separate
6-c
h
annel
l
evel
contro
l
box
is
re
qui
re
d
between
the
mix-down
deck
and
the
mo
nitor
speakers.
Thi
s
is
because
few
s
ma
ll
for
ma
t m
ixi
ng
consoles
ha
ve
p
rovisio
ns
to
sw
itc
handl
evel-manage
a
6-
ch
annel
audio
signal.
The
simp
lest
and
perhaps
best
way
to
acco
mpl
is
h
thi
s
is
to
use
an
external,
S.
ll
evel
co
n
troller.
It
is
placed
between
the
outputs
of
the
m
ix-
do
wn
deck
and
the
monitor
spe
a
kers,
a
llow
i
ng
it
to
con
trol
the
pl
ayb
a
ck
l
evel
w
hi
le
the
mi
x-
do
wn
deck
receives
full-level
recording
signal.
Bass
Manager
and
Volume
Control
•
8-
Track
Mix-
Down
Deck
Console
Outputs
Le
ft
Front
______
..J
RightFront
______
__J
Left
Su
rr
ound
-------
--'
Rig
ht
Su
rr
ound
---------'
Ce
nter
--------__J
LF
E
----------'
18
Beyond
Stereo
to
5.1
Surround
When
using
a
subwoofer
for
the
LF
E
(low
Frequency
Effects)
channel
in
a
5.1
surround
monitoring
system,
rotate
the
low
pass
filter
all
the
way
to
the
rig
ht
to
the
170
Hz
pos
ition.
No
te
th
at
the
LFE
channel
is
set
with
an
additionallOdB
of
monitoring
gain.
To
set
thi
s
leve
l,
we
recommend
using
2-octave
wide,
band-passed,
pi
nk
noise
fro
m
20
to
80Hz
for
the
LFE
channel
and
500
to
2,000Hz
for
the
near-field
speakers.
After
adjusting
each
near-field
mo
ni
tor
one
at
a
time
to
85dB
SPL,
adjust
the
L
FE
channellOdB
louder
to
95dB
SPL.
19
Bass
Management
Theory
Bass
management
is
a
method
for
extending
the
bass
response
of
small,
near-field
speakers
used
in
5.1
surrounds
sound
systems
(familiarly
called
home-theatre
systems)
.
This
is
done
by
routing
frequencies
below
a
cutoff
point
to
a
separate
subwoofer
(sometimes
called
"bass
redirection"
in
home-theater
receivers)
.
This
can
usually
be
enabled
by
selecting
"
Small
Speakers"
from
a
speaker
set
up
menu.
This
process
places
a
group
of
two-way
filters
in
the
speaker
output
path,
typically
at
80Hz
.
These
filter
s
route
all
sonic
energy
above
this
given
frequency
(e
.
g.
80Hz)
to
the
Left,
Center,
Right,
Left
Surround
and
Right
Surround
speakers
.
In
turn,
the
process
redirects
the
low-frequency
energy
from
the
five
full-range
channels
to
a
single
subwoofer,
which
also
reproduces
the
separate
LFE
channel.
Bass
management
is
used
in
practically
every
consumer
home-theater
system.
Therefore
,
audio
engineers
mixing
for
modern
listeners
should
realize
that
their
studio
monitoring
systems
must
be
able
to
reproduce
s
ufficient
low
frequencies
so
th
ey
can
avoid
re
cording
undesirable
subsonic
information
.
Without
such
studio
monitoring,
it
is
possible
to
release
a
mix
with
infrasonic
problems,
such
as
pops,
air
conditioner
rumble,
traffic
noise
,
footsteps,
etc.
These
subsonic
noises
will
be
eliminated
(
masked)
by
the
natural
high-pass
filter
effect
of
using
near-field
monitors
w
ith
a
respon
se
that
goes
down
onl
yas
low
as
40
or
50Hz.
Thus,
infrasonic
problems
may
not
be
recognized
(
heard)
in
the
studio.
However,
since
virtually
all
home-theatre
systems
use
subwoofers
with
bass
management,
consumers
will
hear
these
infrasonic
problems
at
high
volume
levels
in
their
home
.
Bass
management
effectively
extends
the
low-frequency
response
of
near-field
monitors
down
well
into
the
25
to
40Hz
range
(
depending
on
the
subwoofer
used).
This
allows
the
engineer
to
take
evasive
action
in
the
studio,
such
as
engaging
high-pass
filters
on
input
channels
and
microphones
,
adding
pop
filters
and
suspension
mounts
to
microphones
and
correcting
HVAC
and
other
rumble
problems
.
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