Stereo Reproduction
Low Pass Filter:
The subwoofer crossover point should be set having regard to the size and low frequency extension of the main speakers. The role of the subwoofer is to extend the bass response of the system, not to increase the overall bass level. If the loudspeakers are large the crossover should be set low, a value around 55 Hz is a good place to start. With smaller speakers this can be increased, up to 85Hz for the small bookshelf units. As always the final value is determined by listening.
Changing the
The
You can operate the subwoofer with the drive unit firing downwards (amplifier at the rear) or firing forwards (amplifier beneath the subwoofer).
To change the mode from down firing to front firing:
Our ears are far more sensitive to midrange frequencies
Testing the system
The simplest way to test the system is to play, at a moderate level, music with deep consistent bass. Switching the subwoofer on and off should cause change of the depth of bass, and the ambience will also alter. If there is a significant change in bass volume, or a noticeable step in the bass response, or an increase in coloration when the subwoofer is playing, the setup needs to be refined. By selecting different crossover and volume settings, you will be able readily to identify the most favourable combination.
Remove the grille from the front of the loudspeaker
b
Place a towel or similar on the ground.
Invert the subwoofer and place it carefully on the towel. Remove the four cone feet from the subwoofer
c
Dolby Labs Recommended 7.1 Placement
Left Front
Centre | LFE | Right Front |
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| 22º | 30º |
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| Mode |
Front | Firing |
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Screw the cone feet tightly into the holes that held the pegs Stand the subwoofer on its feet as shown in the illustration
e
Unscrew the four pegs that held the grille in place
d
Left Surround
90º
110º
135º
150º
Right Surround
Down | In down firing mode the grille must be removed |
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Firing |
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Mode | Store the grille and the pegs safely for future |
Left Back
Right Back
Reverse the procedure to change the mode. |
(Single Back channel for 6.1
Which mode should I use?
You should experiment with different operating modes to see which one you prefer. Here are some notes which may help you.
Front firing mode keeps the drive unit away from walls and offers a better focussed sound with lowest bess distortion.
If your floor is a hard wood or stone floor,
In front firing mode the amplifier faces downwards so there are some potential disadvantages:
If you have a deep shag pile carpet, there may be insufficient ventilation for the amplifier and we do not advise you to use this mode of operation.
Although the Subwoofer controls are designed to be “set and forget”, if you are likely to adjust the controls often, down firing mode is easier for day to day use.
12 | 9 | 5 |