Setting The Subwoofer Controls

Auto: With the switch set to Auto, the subwoofer will initially become fully active and the indicator will glow green. After about 5 minutes without an input signal, the subwoofer will automatically enter “sleep” mode. The indicator will glow red. When an input signal is detected, the subwoofer will automatically become active and the indicator will glow green. The subwoofer will return to sleep after about 5 minutes with no input signal.

Audio-visual processors incorporating an “automatic” set up procedure may be “confused” by subwoofers with an auto switch-on/sleep function. A potentially damaging fault condition can arise. Subwoofers are best left switched on and fully active during set up if such a processor is used.

Standby: With the switch set to Standby the subwoofer will become active when 12V is applied to the Trigger Input (Item 10 in Figure 1). Zero volts at the input will return the subwoofer to sleep. The indicator will glow green when the subwoofer is active and red when the subwoofer is in sleep.

There are 7 controls to consider:

•The VOLUME (LINE) control (Item 3 in Figure 1)

•The VOLUME (SPEAKER) control (Item 4 in Figure 1)

•The LOW-PASS FREQ (frequency) control (Item 5 in Figure 1)

•The LOW-PASS FILTER switch (Item 6 in Figure 1) Note: This applies only to the LINE input. The filter is always in circuit with the SPEAKER LEVEL input.

•The BASS Extension switch (Item 7 in Figure 1)

•The EQ (equalisation) switch (Item 8 in Figure 1)

•The PHASE switch (Item 9 in Figure 1)

The appropriate settings depend on the equipment used with the subwoofer and the modes of connection. If using more than one subwoofer, ensure the controls on each one are set the same.

Note: The VOLUME (LINE) and VOLUME (SPEAKER) controls only operate on their respective line and volume inputs. An unused volume control is best set to Min.

Home Theatre Settings

Set the VOLUME (LINE or SPEAKER) control initially to the 9 o’clock position.

Set the LOW-PASS FILTER switch to OUT.

Set the EQ switch initially to position A.

Set the PHASE switch initially to 0°.

Set the LOW-PASS FREQ (frequency) control to 140 if the speaker level inputs are used. The setting is irrelevant if the line level inputs are used.

See the “Fine Tuning” section for more.

The subwoofer is 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 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 (LINE or SPEAKER) control initially to the 9 o’clock position.

Set the LOW-PASS FILTER switch to IN.

Set the EQ switch initially to position A.

Set the PHASE switch initially to 0°.

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 B&W 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

0.9times 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

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 out (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