4 M86 Operation
23
should sound like the center loudspeaker is actually
on, even though it’s disconnected.
6. Reconnect the center loudspeaker and return the
LC and CR Setup switches to the out position.
7. Correct system connection and operation can be
verified using the LC and CR Setup switches
independently as described in sections A1-A8
above.
Setup Adjustment of the Surround Level
With the M86 Surround Output level control and the
Stereo Input Surround level control at the center
position, the surround amplifier gain controls are
adjusted for normal operating level. This way, if
further adustment is made on the M86 (such as for
a particular program source), then it is easy to
return the surround system to the preset level.
The ‘correct’ level for the surround loudspeakers is
somewhat subjective and arbitrary. The surround
amplifier gain controls are used to set the surround
level while listening to the system with appropriate
program material. If a 5.1 source (such as DVD
player) will be used then a ‘typical’ DVD, preferably
a music DVD (where the surround level is usually
more critical) should be used as a program source.
The center of the listening area is usually the best
place to listen when adjusting the surround level.
While it is actually a matter of preference, a popular
level for the surround channels with music program
material is such that the surround sound field is
barely audible compared to the front channels. For
movies, the surround loudspeakers can be higher
so that during surround effects, their level is com-
parable to the front. Be sure to balance the left and
right surround levels when adjusting the amplifiers.
If 5.1 sources are rarely or not used then the
amplifiers should be adjusted using a left/right
stereo program source.
One way of adjusting this precisely is by setting the
C/S Image Balance control fully clockwise to "Diff".
Then, using ‘typical’ stereo program material, adjust
the surround amplifier gains so that the surround
loudspeakers are balanced at the same level with
the front left and right loudspeakers. Listening at the
center of the listening area, a well-balanced
surround effect should be heard with the surround
signal heard evenly from all directions. Then return
the C/S Image Balance control to its center position,
and the resulting surround level should be correct.
To adjust for individual program variations, the
Surround Output level control is used for 5.1
sources. Either the Surround Output level control or
the Stereo Input Surround level control can be used
to adjust the derived surround from a left/right
stereo source.
4 Multisonic Imager Operation
Control Adjustments
Input Level Control Operation
The Stereo Input Level control on the M44 or M86
affects the overall gain of the stereo input signals to
all of the outputs. On the M86 it will also affect the
left and right inputs from the 5.1 source only when
the ‘5.1-to-Multisonic’ switch is pressed. It does not
affect signals at the Discrete Center and Discrete
Subwoofer inputs.
This control can be used as an overall volume
control for the stereo input sources.
With the control at midpoint, the unit will operate just
a little (about 2 dB) over unity gain but there is an
additional 6 dB gain due to the outputs being
symmetrical (balanced) which provides an extra 6
dB of gain and headroom. In most applications, the
straight-up position or higher is optimum. A lower
position is ok when full power is not expected or
when the power amplifiers (or other subsequent
equipment) have higher gain than needed.
C/S Image Balance Control Operation
The C/S Image Balance control sets the parameters
used in the Multisonic Dispersion Matrix circuit. It
will effectively control the “width” of the mix. The
program material must be a stereo mix, or have
SpreadSound applied, to be able to adjust this.
One option in setting this control, for a recorded or
pre-mixed signal source, is to adjust it so that all
three loudspeakers have the same loudness. To do
this, it usually helps to be a bit off-center in the
listening area. Simply adjust the C/S Image Balance
control until the center and side loudspeakers seem
to have the same output level. Under this condition,
you will have the maximum possible separation and
optimum Multisonic dispersion for that program
source.
Another method is to listen carefully to the mix and
adjust the control for a good level balance between
the prominent, central parts of the mix (such as lead
vocals, if present and centered) and the side or
ambient parts of the mix. If the central portion of the
program material is either too dominant or too weak,
this control can be used to compensate and correct
it. Recordings vary in the way they are mixed, and
for the most critical and optimum results, the C/S
Image Balance control can be used to optimize for
each recording.
