340Razur
13
ENGLISH
Because the speakers in a surround sound system are usually different
distances from the listener the 340R incorporates the ability to apply a
variable digital delay to each of the channels so that the sound from
each arrives at the same time at the listening position for best surround-
sound effect. Each pair of speakers (i.e. Front Left and Right or Surround
Left and Right) are subject to the same delay and so must be situated
equidistant from the listener.
To set the delay times simply measure the distances from the listening
position to each speaker as shown in the following diagram:
Note: No delay setting for the subwoofer is necessary.
Set the distances in the OSD Speaker Delay menu to the nearest value
in metres (1 foot = 0.3 metres). The speed of sound is approx 340
metres per second, the 340R thus introduces approx 3mS of delay per
metre of distance set.
Go to the ‘Speaker Delay Menu’ and highlight each speaker in turn. Set
the distance to the nearest value to that which you measured by using
the Left and Right arrows (the values do not need to be exact):
Press the OSD button to exit the menu.
Note: In addition to the delays as set above Dolby Pro Logic II playback
also requires an extra 15 milliseconds delay to the surround channels
only. This extra delay is part of the Dolby Pro Logic II specification and
ensures that sound from the surrounds arrives just after sound from the
front reducing the audibility of sound leakage from the front to the
surround speakers. Because the relationship between the Dolby Digital
and Dolby Pro Logic II two delays is fixed (15mS extra to the surround
channels), it is only necessary to set the delay by measuring the
distances as we have described. The 340R will automatically provide the
appropriate extra delay whenever you switch to a Pro Logic Mode.
1
2
3
1 = Front Left & Right
speakers
2 = Centre speaker
3 = Surround Left & Right
speakers
2. Speaker delay
The 340R 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 340R 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
