Altec Lansing 15 Walnut User Manual
Page 2
Attention! The text in this document has been recognized automatically. To view the original document, you can use the "Original mode".
10
20
50
100
200
500
1000 2000
FREQUENCY IN HERTZ
5000 10000 20000
Figure 2. Typical Response of Model 19 with
Optimum Control Settings
Electrical Connections
Two
terminals
at
the
underside
of
the
cabinet
connect
leads
from
the
amplifier,
if more than one Studio Monitor Speaker
System
is
connected
to
the
amplifier(s),
be sure to observe polarity so that proper
acoustic phasing is achieved.
Removal of Grilles
‘Push-and-lock’
fasteners
secure
each
grille to the cabinet. To remove a grille,
simply
grasp
the
upper
corners
and
pull
firmly outward. To put the grille back on,
align it with the cabinet and press
each
corner
until
firmly seated.
For the Model
15,
also
press
the
center
of
the
grille,
just below the horn area, to engage the
central fastener.
Frequency Controls
Two frequency controls are located on the
network/equalizer
assembly,
behind
the
grille (lower grille for the Model 19. When
the controls are positioned in the OPTI
MUM
area
of
adjustment,
a
‘flat’
fre
quency
response
is
obtained
for
most
acoustic
environments.
Figure
2
shows
a
typically
‘flat’
response
of
the
Model
19
when both
frequency controls are set in
the OPTIMUM area of operation.
10
20
50
100
200
500
1000 2000
FREQUENCY IN HERTZ
5000 10000 20000
SOLID LINE = HF AND MF CONTROLS FULLY CLOCKWISE
BROKEN LINE = HF AND MF CONTROLS FULLY COUNTERCLOCKWISE
Figure 3. Typical Response of Model 19 with
Controls at Maximum and Minimum Positions
SOLID LINE = HF CONTROL FULLY COUNTERCLOCKWISE,
= MF CONTROL FULLY CLOCKWISE
BROKEN LINE = HF CONTROL FULLY CLOCKWISE,
= MF CONTROL FULLY COUNTERCLOCKWISE
When
the
HF
LEVEL
control
is
turned
counterclockwise
from
the
OPTIMUM
area,
the
higher
frequencies
are
‘rolled
off or reduced in volume. This enhances
the bass and mid-range frequencies.
When
the
MF
LEVEL
control
is
turned
counterclockwise
from
the
OPTIMUM
area, the mid-range frequencies are atten
uated, producing a ‘dip’ in the mid-range
portion
of
the
audio
spectrum.
This
enhances the bass and treble frequencies.
Turning
the
control
clockwise
from
the
OPTIMUM
area
enhances
the
mid-range
frequencies.
Figure
3
shows
effects
to
the
audio
spectrum
when
the
two
controls
are
turned
fully
‘up’
or
‘down’.
With
both
controls
‘up’
(solid
line),
both
mid-range
and treble frequencies are enhanced. With
both
controls
fully
‘down’
(broken
line),
the
same
frequencies
are
attenuated,
which enhances the bass frequencies.
Figure
4
shows
effects
to
the
audio
spectrum when the controls are turned to
extreme
opposites
to
one
another,
with
Figure 4. Typical Response of Model 19 with
Controls at Opposite Maximum and Minimum Positions
one control fully ‘up’ and the other con
trol
fully
‘down’.
With
the
HF
control
‘down’
and
the
MF
control
‘up’
(solid
line),
mid-range
frequencies
are
enhanced
and
treble
frequencies
are
attenuated.
With the HF control ‘up’ and the MF con
trol
‘down’
(broken
line),
mid-range
fre
quencies
are
attenuated
and
treble
fre
quencies are enhanced.
Maximum
range
of
the
two
controls
is
nominally
14
dB.
Upon
inspection
of
the
curves shown in Figures 3 and 4, some
interaction is seen between the two con
trols.
This
control
interaction
prevents
extreme
imbalance
between
mid
to
high
response,
and
assures
minimum
phase
shift
through the crossover network.
Con
trols
for
the
Model
15
function
in
a
similar manner.
By
experimenting
with
these
controls, you
may
determine
which
particular
settings
produce
the
most
pleasing
effects
for
your acoustic environment.
SERVICE INFORMATION
Speaker
system
components
may
be
detached
from
the
cabinet
by
removing
appropriate
mounting
screws.
The
low-
frequency
loudspeaker
and
the
network
assembly each mount to the cabinet with
four
screws
(see
Figure
5).
The
Model
19
horn/driver
assembly
is
mounted
to
the
upper
part
of
the
cabinet
with
six
bolts,
which
are
accessible
when
the
acoustic
damper
pad
is
removed.
The
Model 15 horn/driver assembly is mounted
with four bolts. The driver and interfacing
gasket are attached to the horn with two
nuts
and
two
washers
(see
Figure
6).
Electrical
connections
are
made
in
accordance
with
the
schematic
diagram
of Figure 7.