Arcam Solo sub, Handbook

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E-9 E-8
English
Solo sub and speaker
positioning
The advice given here is a general
guideline for setting up speakers. Refer
to the documentation supplied with your
speakers for more precise information. Visit
www.dolby.com for usefuI information on
listening-room layouts.
Room acoustics
Your room’s shape and how it is furnished
will affect the sound you hear. For instance,
too many bare surfaces may cause a
harshness to the sound. Carpets, wall-
hangings and curtains can all help.
If you have a choice of listening rooms,
avoid one that is perfectly square or has one
dimension exactly twice another. Such a
room can aggravate resonances that colour
the sound.
The closer you place a speaker to corners
and the intersection of wall and floor or wall
and ceiling, the stronger the bass output,
which may over-emphasise the bass. Moving
a speaker just a few inches can sometimes
make a big difference.
Speaker setup
Proper speaker placement is the key to
achieving the best home theatre sound
(see diagrams). As a rough guide, speakers
should be placed on rigid stands about 15cm
from the rear wall and at least 60cm from
any side wall.
Speakers should never be placed on the floor
(unless they are floor-standing speakers),
or in corners. Speaker drivers should be at,
or a little above, ear level when seated. If
possible, centre your seating area between
the surround speakers.
Sound will depend on the acoustics of
the listening room so experimenting with
speaker positioning is very worthwhile.
Subwoofer
The location of the Solo sub will affect
the overall sound quality. Placing it next
to a wall or in a corner will often boost
efficiency and give a cleaner low bass
sound. However, all rooms react differently
and we recommend that you experiment
with positioning by allowing at least 15cm
clearance between the walls and the unit.
Speaker stands
The more firmly a speaker is held, the better
it will sound. We recommend the use of
rigid metal stands of 40–60cm height.
Ensure that the stands and/or speakers do
not wobble. Properly damped stands that
do not ‘ring’ when tapped with a pencil, will
bring out the best in a speaker.
Solo sub used with a home cinema
0˚
90˚
110˚
22˚
30˚
C
R
L
LS
RS
calibration
The Solo sub has two roles: firstly to
reproduce accurately and with sufficient
power the sub-bass that other ‘smaller’
speakers cannot; and secondly to reproduce
the ‘.1’ or low frequency effects (LFE) track
of 5.1 or 7.1 material.
For optimum results, the Solo sub must
be set up in the correct relation to the
other speakers in your system. The two
relevant controls are the
crossover point
and the volume level . The crossover point
establishes the frequency below which
signals are redirected away from ‘small’
speakers toward the subwoofer. Setting
the volume level ensures signals that are
of equal volume achieve the same sound
pressure level no matter what frequency
they are or which speaker they come from
(i.e. subwoofer or satellite speaker). In most
surround-sound systems, two crossovers
are available: one in the surround-sound
decoder and one in the Solo sub.
To get the optimum sound in a variety of
systems, the Solo sub allows these controls
to be used independently for systems with
‘Large’ front speakers and an LFE output
from the surround-sound decoder.
Crossover frequency
In most systems, a X-OVER FREQ point of
85 is recommended.
If your speakers are very ‘small’ (and thus
cannot reproduce much bass) you might like
to set the crossover point higher than this
figure to allow the Solo sub to do more of
the work. However, be aware that the higher
the crossover point, the more directional
the low frequency sounds, thus the more
easily identifiable is the subwoofer’s physical
position.
If your speakers can reproduce reasonable
bass, you can try a lower crossover point.
Experimentation and listening will guide
you to the right spot.
Crossover Q
The X-OVER Q setting controls the slope
of the trace beyond the cutoff frequency, in
dB/octave. As a rough guide, a X-OVER Q
setting of 1.1 is recommended.
The aim is to make a ‘mirror image’ match
with the slope of the high-pass filter. A steep
cut-off of the high-pass filter from the sound
processor/receiver should be matched by a
steep cut-off of the low-pass filter from the
Solo sub.
Similarly, if the sound processor/receiver
provides a more gradual cut-off, the
X-OVER Q setting should have a lower
value.
Volume
Accurate volume setting for a subwoofer
ideally requires specialist measuring
equipment such as a Real Time Spectrum
Analyser or RTA. A regular Sound Pressure
Level (SPL) meter will not work for this!
For most systems though simple
experimentation by ear will suffice. Start
with a medium setting ( 6 ) and experiment
with VOLUME until low frequency sounds
can be heard as part of the main sound and
not traceable to the subwoofer directly.
Most sound processors or receivers allow
Sub levels to be trimmed ‘on the fly’ to
counter excessively high or low levels from
particular source material.
Phase
The PHASE button has two settings: 0°
(button out) and 180° (button pushed in).
A phase delay may be used to counteract
the effect of sound waves from the Solo sub
interacting with and partially cancelling
out or unduly emphasising sound from
the satellite speakers. This effect depends
critically on the relative positioning of
subwoofer and satellite speakers and
can also be remedied by relocating the
subwoofer a short distance. The phase
setting is available if relocation is not
possible or impractical.
0
-12
Q=1.5
Q=1.0
Q=0.7
Q=0.5
Q=0.6
Q=0.3
0
40 60 80 100 120 140 160
-12
20
Crossover frequency Hz Crossover frequency