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Movie only setup through the LFE input.
This dedicated line level input is specifically for
the LFE (Low Frequency Effects) output from a
surround sound A/V processor. Please note that
single ended (phono) or balanced (XLR)
connections are available, however, they must
not be used simultaneously. The LFE input to the
subwoofer will not be affected by the Frequency
or Slope controls which apply only to the Left
and Right channel line inputs.
Once your subwoofer is connected and powered
up it needs to be integrated into your home
cinema system. To do this you will need to follow
the set-up procedure for your surround sound
processor. Set the subwoofer level to near
maximum and the phase to 0. In the surround
sound processor’s speaker menu, ensure that the
subwoofer is set to ‘on’. If using smaller satellite
speakers then set the speaker size to ‘small’. KEF
would recommend starting with the ‘small’
setting if you are unsure.
If you are using full range speakers set the
speaker size to ‘large’. Use the processor’s
controls to adjust the level of the subwoofer
at the same time as setting each of the
channel levels.
Music only setup through the Left/Right inputs.
To increase the low-frequency extension of your
existing stereo speakers connect the amplifier’s
line level outputs to the subwoofer Left and Right
line level inputs. If line level outputs are not
available then connect the Left and Right amplifier
high level speaker outputs to the speaker inputs of
the subwoofer. Once the subwoofer is connected
and the power is switched on it needs to be
acoustically integrated into your existing system.
To do this you will need to use the Level,
Frequency and Phase controls.
First select the subwoofer low-pass filter slope
to match your main speakers. For a bass reflex
speaker the slope should be set to 24dB/octave.
This applies to all the KEF Reference Series
loudspeakers. For a closed box loudspeaker,
however, the slope should be set to 12dB/octave.
Select a piece of music that you are familiar with
which has a constant, repetitive bass line.
Start with the Level and Frequency controls at
the middle positions and the phase control set to
0. Adjust the level control until you are happy
with the low frequency levels when compared
with the main speakers. Now adjust the
Frequency control so that there is no obvious
change in the level of the sound from very low
frequencies to higher frequencies. Adjust the
polarity and the phase control to achieve the
smoothest integration between the subwoofer
and the main speakers. KEF recommend you take
some time making fine adjustments to the
controls, whilst listening to a varied selection of
music, until you are satisfied with the sound
balance.
Combined movie and music setup.
The Reference Series 208 subwoofer can be used
for both main speaker low frequency extension
and the LFE channel reproduction for a surround
sound system.
Set the subwoofer up as described in section
‘Music Only Setup’. With the subwoofer
correctly set up for stereo use, connect the LFE
output from your surround processor to the LFE
line level input of the subwoofer. Without making
any adjustments to the subwoofers controls,
including the volume level, follow the set-up
procedure on your surround processor to adjust
the subwoofer volume level (as described in
section ‘Movie Only Setup’).
Connecting to the speaker inputs (high level).
Speaker level or line level inputs are available to
allow flexibility in set-ups for the Left and Right
inputs. The specific LFE input is line level only to
interface with an A/V processor.
The speaker input terminals will accept bare
wire, spade or 4mm connectors. Most good
quality loudspeaker cables have some indication,
such as colour coding or ‘ribbing’ on the
insulating material, indicating which conductor is
‘+’ or positive. Connection to the subwoofer can
then be made as follows:
The left channel amplifier output terminal marked
‘+’ or coloured RED connects to the left
subwoofer speaker input terminal marked ‘+’.
The left channel amplifier output terminal marked
‘-’ or coloured BLACK connects to the left
subwoofer speaker input terminal marked ‘-’.
Similarly, these instructions should be followed for
making connections between the right channel
amplifier output and the right subwoofer speaker
input terminals. Correct polarity, or phase, is vital
to the proper operation of the system.
Bare wire connections are the simplest to
achieve and involve stripping 12.5mm (1.2in.) of
insulation to expose the loudspeaker wire core.
(You should twist together, using clean fingers,
the ends of each multi-stranded core prior to the
next stage to ensure a good signal contact).
Having unscrewed the lower terminal cap, push
the wire through the exposed hole in the
terminal body and screw the cap down tightly.
Make sure that no stray strands come into
contact with the opposite terminal; this could
cause a short circuit between the terminals and
may damage your amplifier.
Be aware that a higher quality run of cable will
always give a more rewarding presentation than
multiple runs of an inferior cable.
Poor quality cables can seriously compromise the
overall sound of your hi-fi system.
KEF recommends that high quality loudspeaker
cable be used for connecting to your Reference
Series Model 208 subwoofer high level inputs.
It is good practice to keep the cables as short
as possible.
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