4
ideally, the f
requenCY
control should be set to the frequency
where your main speakers’ low-frequency response roll-off is
–3db. however, this is usually impossible to determine
without sophisticated test equipment since each listening
room has a different influence on your main speakers’ bass
performance.
n
oT e
: T
h e
f
r e q u e n C Y C o n T r o l D o e s n oT f u n C T i o n w h e n
T h e
b
Y pa s s b u T To n i s i n T h e
on
p o s i T i o n
.
P
hase
switch
when the a150’s p
hase
switch is in the 0° position, a positive
input voltage will cause the bps-1 subwoofer’s speaker cone
to move
out
(towards the room). when the p
hase
switch is in
the 180° position a positive input voltage will cause the sub-
woofer cone to move
in
(away from the room).
There is no absolute correct setting for the p
hase
switch.
Depending on the location of the subwoofer relative to your
main speakers and seating location, one of the settings will
produce a better match with the main speakers, improving bass
impact and in some cases, improving overall bass level as well.
To determine the correct setting of the p
hase
switch, listen to
music with significant impactful bass content with the switch in
each position (it may be helpful to sit in the normal listening
position while someone else changes the p
hase
switch between
0° and 180°). leave the switch in the position that produces
audibly louder bass with more impact.
n
oT e
: T
h e
p
h a s e s w i T C h w i l l f u n C T i o n n o m aT T e r w h aT
p o s i T i o n T h e
b
Y pa s s s w i T C h i s s e T i n
.
v
olume
control
The V
olume
control sets the bps-1 subwoofer’s volume. when
setting the a150’s V
olume
control by ear, try to find a volume
setting where the bass sounds balanced on both music and
films. listen to several different music recordings and film
soundtracks that contain strong bass passages and try to find
a setting for the V
olume
control that doesn’t over-emphasize
the bass or make it sound weak.
The most accurate way to set the V
olume
control is with
calibrated test noise or test tones and a sound-pressure level
(spl) meter or real-time analyzer. There are several CDs and
DVDs that contain subwoofer test signals. if you use an spl
meter, set the a150’s V
olume
control so that the bps-1
subwoofer plays at the same volume as the system’s other
speakers.
n
oT e
: T
h e
V
o l u m e C o n T r o l D o e s n oT f u n C T i o n w h e n T h e
b
Y pa s s s w i T C h i s i n T h e
on
p o s i T i o n
.
built-in limiter
The a150 has a built-in limiter that prevents overdriving the bps-
1 subwoofer. This allows the bps-1 subwoofer system to pro-
duce optimium bass output while maintaining long-term reilia-
bility. The limiter has no user or installer adjustments.
specifications
a150
Power Output:
90 watts RMS @ 4 ohms
Power Output (Program):
150 watts @ 4 ohms
Frequency Response:
31Hz - 150Hz (variable to 40Hz)
Total Harmonic Distortion:
.05% 20Hz - 300Hz @ 8 ohms
Signal-to -Noise Ratio:
–95dB (w/22kHz A-WTG filter)
Input Sensitivity (Stereo Inputs): 25mV for 90W @ 4 ohms (volume
control @ max)
Input Sensitivity (LFE, Mono Input): 600mV for 90W @ 4 ohms
(Bypass model)
Input Impedance:
20k ohms
Hi-Level Out Hi-Pass Filter: –3dB @ 200Hz, 6dB/octave
Line Level Out Hi-Pass Filter: –3dB @ 150Hz, 6dB/octave
Power consumption:
160 watts maximum (4 ohms, full
power); 13 watts idle (no signal)
AC Fuse (120V Version):
4A (T4AL ~250V)
AC Fuse (230V Versison):
2A (T2AL ~250V)
Speaker Fuse (One BPS-1): 1.6A (T1.6AL ~250V)
Speaker Fuse (Two BPS-1s): 2.0A (T2AL ~250V)
Heat Output:
98 BTU/HR @ 8 ohms (rock music);
140 BTU/HR @ 4 ohms (rock music)
Dimensions (W x H x D):
16¾" x 4" x 13½"
(425mm x 102mm x 343mm)
Dimensions w/Rack Ears
(W x H x D):
19" x 4" x 13½"
(489mm x 102mm x 343mm)
Rack Space Requirements: 2U
Shipping Weight:
20 lbs (9.1kg) each
sonamp
®
a150 subwoofer amplifier
