7
Set the EQUALISATION switch to MUSIC.
Set the LOW-PASS FREQ control to match the -6dB
low frequency cut-off frequency of the satellite
speakers. Note: Both -3dB and -6dB figures can be
found in the specification of each Bowers & Wilkins
speaker model. If the satellite speaker manufacturer
quotes only a – 3dB frequency, the optimum setting
for the LOW-PASS FREQ control should be between
0.6 and 0.9 times that figure. The more gradual the
low frequency roll-off of the satellite speakers, the
lower the frequency should be set.
See the Fine Tuning section for more.
Fine Tuning
Before fine tuning, make sure that all the
connections in the installation are correct and
secure.
Home Theatre
In home theatre systems, the subwoofer (LFE) signal
is a separate channel rather than an extension of
the signal to the satellite speakers. The LOW-PASS
FILTER is switched off (or set to maximum), because
the processor provides all the filtering for any
speakers set to “small”. However, the position of the
PHASE switch must still be assessed. Normally the
phase will be set to 0°, but if the subwoofer is
positioned at a distance significantly different from
the other speakers, or the power amplifier driving
the other speakers happens to invert the signal, the
180° position may be preferable. Listen with the
switch in both positions and choose the one that
gives the fullest sound. If there is little difference,
leave the switch at 0°.
Surround sound processors normally have a
calibrated noise signal that can be used to set the
relative levels of all the speakers, making the task
somewhat more straightforward than for 2 channel
audio. However, do not be afraid to alter the
settings to your personal preference. It is all too
easy to get carried away with the capabilities of the
subwoofer, especially with some special low-
frequency effects. Often a more realistic portrayal,
and one more satisfying in the long term, is to be
had by setting the subwoofer level lower than the
standard calibration level.
2-channel Audio
Set the system up in the preferred position and play
some programme with a steady bass content.
The optimum settings of the PHASE switch and the
LOW-PASS FREQ control are inter-related and also
dependent on the low-frequency cut-off
characteristic of the satellite speakers. However, the
settings recommended above for the LOW PASS
FREQ control and PHASE switch have been chosen
to integrate well with most satellite speaker bass
alignments.
Using the initial settings, first check the setting of
the PHASE switch. Choose the option that gives the
fullest sound. Normally the recommended option will
be optimum, but may not be in certain
circumstances. These may be that the power
Setting The Subwoofer Amplifier Controls
There are 6 controls to consider:
The VOLUME (LINE) control.
The LOW-PASS FREQUENCY control.
The LOW-PASS FILTER switch.
The BASS Extension switch.
The EQUALISATION.
The PHASE switch.
The appropriate settings depend on the equipment
used with the subwoofer and the modes of
connection. If using more than one subwoofer
amplifier, ensure the controls on each one are set
the same.
Home Theatre Settings
Set the VOLUME control initially to the 9 o’clock
position.
Set the LOW-PASS FILTER switch to OFF.
Set the BASS EXTENSION switch initially to
position A.
Set the PHASE switch initially to 0°.
Setting the LOW-PASS FREQ setting is irrelevant as
the filter is switched OUT.
Set the EQUALISATION switch to MOVIE.
See the “Fine Tuning” section for more.
The subwoofer and subwoofer amplifier are not a
THX
®
licensed component, but may be used with a
THX
®
controller if desired. If a THX
®
controller is
used, ensure that the subwoofer function is enabled.
This incorporates all the filtering and level setting
required for the subwoofer in all modes. For level
calibration, the internal test noise and channel level
controls in the THX
®
controller should be used. In all
cases the levels should be set to obtain 75dB SPL
(C-weighted) at the listening position from the
controller’s internal noise test signal.
With other processors, configure the front and
surround speakers to “large” or “small” as
appropriate before setting the levels. Use the
internal noise test signal and volume controls of the
processor to set the levels of all the speakers. Only
change the VOLUME control on the subwoofer
amplifier if there is not enough range in the
processor to achieve the correct levels. Inexpensive
sound level meters are readily available from
electronics stores and can be used to calibrate the
levels. Refer to your processor manual for further
details on how to set the levels.
2-channel Audio Settings
Set the VOLUME control initially to the 9 o’clock
position.
Set the LOW-PASS FILTER switch to ON.
Set the BASS EXTENSION switch initially to
position A.
Set the PHASE switch initially to 180°.
7575 CTSWxx SA1000 Inside increased margin.qxd:7575 CTSWxx SA1000 Inside.qxd 29/3/11 16:19 Page 7