16
The 640R allows level calibration to match the acoustic level between
different types/sizes or even manufacturers of speaker that may be
being used for each channel. This is achieved by adjusting the relative
level of each speaker through the ‘Level Calibration’ menu in the OSD.
The basic process is to listen to or measure with an SPL meter (more
accurate and recommended but not essential) the level of sound
produced by each speaker and set relative levels for each speaker so
that they all sound the same loudness at the normal listening position.
The 640R incorporates a Test Signal Generator (broad-band white noise)
to facilitate this.
Set the unit to a normal listening level or half maximum volume
approximately. Press the OSD button on the remote control then select
the ‘Level Calibration’ menu. Now turn on the test signal by highlighting
this item and pressing the Left or Right arrows:
A “rushing” or “hissy” sound should be heard, initially through the Front
Left Speaker.
You can now move up and down the channels using Volume Up/Down
on the remote. Each time a new channel is selected the test signal will
be heard to move to that channel. Compare the loudness of all channels
as heard at the listening position.
Now adjust the channels so they all sound the same (in terms of
loudness only, channels of different frequency responses can sound
different in terms of the “tone” of the sound i.e. more or less hissy).
Pick the channel that sounds most different and select it to listen to the
test signal. Now adjust the relative level in dB (using Arrow left/right on
the remote) and continue comparing it to other channels until it is of
equal loudness. The level can be adjusted up to + or - 10dB in 1dB
steps. Repeat the process with the next loudest channel etc. Once all
channels sound the same in terms of loudness, press the OSD button
again to save the settings and exit the menu.
3. Level calibration
Surr. Back L : 0dB
Surr. Back R : 0dB
The next step is to select each source input in turn on the 640R and tell
the unit:
• The type of audio connection you want to use for that source (Analog
or Digital input)
• The type of video connection you want to use for that source
(Composite, S-Video or Component)*
• The processing mode for that source
The
640R
remembers
these
settings
individually
for
every
source
input
and
automatically
recalls
them
as
and
when
you
change
source
input.
* Remember if you wish to use HDMI for any sources this is achieved by
assigning HDMI sources in the OSD in Step 5.
Audio connection type
Select the ‘Input/Output Setup’ menu. Highlight each source in turn
select either analog or digital input types (use the Left and Right
arrows):
Analog inputs will require a stereo phono/RCA to phono/RCA cable
connection to the 640R. Digital inputs will require either a 75ohm digital
type phono/RCA to phono/RCA co-axial cable (SPDIF) or an optical fibre
cable (TOSLINK). The 640R will automatically use whichever is
connected. Do not make connections to both the Optical and Co-axial
inputs for a source.
Note: The Preamp output item at the bottom of this menu selects
between Normal mode (the default), Pre Out Mode (when external power
amps are used) and Ext 2 Ch Mode (where external power amps for front
left and right only are used). These options are covered later. Make sure
this setting shows Normal.
Once you have set the audio types exit the OSD to save.
This setting can also be changed at any time without using the OSD by
pressing the Audio Input Type button on the front panel or remote, this
will then cycle between analog or digital input types for the currently
selected source, as usual they will then be remembered the next time
you return to that source.
4. Source setup
