4
2-channel audio
The optimum settings of the PHASE switch and
the LOW-PASS FREQUENCY control are inter-
related and also dependent on the low-frequency
cut-off characteristic of the satellite speakers and
the relative positions of all the speakers in the
installation.
Set the system up in the preferred position and
play some programme with a steady bass
content. The optimum setting for the LOW-PASS
FREQUENCY depends on several variables; the
bass performance and power handling of the
satellite speakers, the number of subwoofers
used and their position relative to the satellite
speakers. The range 80 – 90Hz is a good
starting point for the LOW-PASS frequency.
Unless two subwoofers are used to preserve
separate right and left channel information and
are sited close to the relevant satellite speakers,
using a higher cut-off frequency may compromise
the stereo image and should only be considered
if the bass performance of the satellite speakers
is particularly limited.
At each setting of the cut-off frequency, listen
with the phase switch in both positions. The
correct one is that which gives the fullest bass
and that will depend on the bass characteristics
of your satellite speakers and the relative
distances of the subwoofer(s) and the satellite
speakers to the listeners. When using more than
one subwoofer, ensure that each one has its cut-
off frequency and phase switch set the same
way.
Set the loudness of the subwoofer relative to the
satellite systems to your liking. Use a wide
variety of programme material to get an average
setting. One that sounds impressive on one piece
may sound overpowering on another. Listen at
realistic levels as the perception of balance
varies with sound level.
Home theatre
The situation with home theatre is somewhat
different from 2-channel audio. The subwoofer
(LFE) signal is a separate channel rather than an
extension of the signal to the satellite speakers.
The LOW-PASS filter is switched out, because the
decoder provides all the filtering for any
speakers set to “small”. However, the position of
the phase switch must still be assessed. Normally
the phase will be set to 0˚, but if the subwoofer
is positioned at a distance significantly different
from the other speakers, or the power amplifier
driving the other speakers happens to invert the
signal, the 180˚ position may be preferable.
Listen with the switch in both positions and
choose the one that gives the fullest sound. If
there is little difference, leave the switch at 0˚.
Decoders normally have a calibrated noise
signal that can be used to set the relative levels
of all the speakers, making the task somewhat
more straightforward than for 2-channel audio.
However, do not be afraid to alter the settings to
your personal preference. It is all too easy to get
carried away with the capabilities of the
subwoofer, especially with some special low-
frequency effects. Often a more realistic
portrayal, and one more satisfying in the long
term, is to be had by setting the subwoofer level
lower that the standard calibration level.
All applications
If you get problems with lumpy bass – if certain
bass notes are exaggerated more than others –
then you probably have a room interface
problem and it is worth experimenting with the
placement of the subwoofer. What may seem
like small changes in position – 15cm (6in) or so
– can have a profound effect on the sound. Try
raising the subwoofer clear of the floor as well
as lateral movement. The use of multiple
subwoofers can smooth the effects of room
resonances, as each subwoofer will tend to
excite resonances at different frequencies. If you
alter the relative distances from the subwoofer(s)
and satellite speakers to the listeners
appreciably, reassess the phase switch setting.
You should also check the level setting of the
subwoofer (using either the decoder output levels
or the volume control on the subwoofer amplifier
as appropriate), but only after setting the phase
correctly.
Taking care of the subwoofer
Do not use the subwoofer as a table. When in
use, objects left on top of the subwoofer are
liable to rattle. In particular, avoid the risk of
liquids being spilled (eg from drinks or vases of
flowers).
If the system is taken out of use for a long
period, disconnect the subwoofer from the power
supply.
Note:
The subwoofer will automatically shut
down if driven excessively. If this occurs, re-set
the subwoofer by turning it off then on again,
using the power on/off switch on the amplifier
panel.
FRANÇAIS
IMPORTANTES
INSTRUCTIONS
CONCERNANT
LA SÉCURITÉ
Attention :
Pour réduire le risque d’électrocution, ne pas
démonter le panneau arrière et ne pas exposer
l’appareil à l’humidité ou à la pluie. Il n’y a
aucun élément susceptible d’être modifié par
l’utilisateur à l’intérieur. Adressez-vous toujours à
un technicien agréé.
Explication des symboles graphiques :
L’éclair dans un triangle équilatéral
indique la présence interne de
tensions électriques élevées
susceptibles de présenter des
risques graves d’électrocution.
Le point d’exclamation dans un
triangle équilatéral indique à
l’utilisateur la présence de conseils
et d’informations importantes dans
le manuel d’utilisation
accompagnant l’appareil. Leur
lecture est impérative.
PRÉCAUTIONS IMPORTANTES :
1
Lisez ce manuel d’utilisation
– Tous les
conseils de sécurité et de fonctionnement
doivent être attentivement lus avant de faire
fonctionner l’appareil.
2
Conservez ce manuel
– Vous devez
pouvoir vous y référer dans le futur,
notamment pour les instructions concernant la
sécurité.
3
Suivez les recommandations
– Toutes
les recommandations concernant la sécurité
durant le fonctionnement doivent être
rigoureusement suivies.
4
Suivez les instructions de
fonctionnement
– Veuillez exclusivement
vous conformer aux instructions qui suivent,
concernant l’utilisation et les réglages de cet
appareil.
5
Installation
– Veuillez respecter les
consignes données par le constructeur.
6
Alimentation
– Cet appareil doit
exclusivement être alimenté suivant les
caractéristiques (tension, fréquence du
secteur) indiquées sur l’étiquette collée en
face arrière. En cas de doute, consultez
immédiatement votre revendeur.
7
Mise à la terre ou en phase
– Cet
appareil ne nécessite pas de mise à la terre.
ATTENTION
RISQUE D’ÉLECTROCUTION
NE PAS OUVRIR
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