Bowers & Wilkins DS8 - Manual (Page 8)

5
4 CONNECTIONS
All connections should be made with the
equipment switched off.
The terminals accept a variety of cable
terminations to suit most applications –
4mm banana plugs, 6mm and 8mm
(1/4 in and 5/16 in) spades, or bare wires
up to 6mm (1/4 in) diameter.
Important safety notice
In certain countries, notably those in
Europe, the use of 4mm banana
plugs is considered a potential safety
hazard, because they may be
inserted into the holes of
unshuttered mains supply sockets. In
order to comply with European
CENELEC safety regulations, the
4mm holes in the ends of the
terminals are blocked by plastic pins.
If you are using the products in any
country where these conditions
apply, you should ensure that any
banana plugs cannot be used in an
unsafe manner by children or other
uninformed persons.
Ensure each positive terminal on the
speaker (coloured red and marked +) is
connected to the positive output terminal
of the amplifier and negative (coloured
black and marked -) to negative.
Incorrect connection may result in
impairment of frequency response, poor
imaging and loss of bass.
Always screw the terminal caps down
fully to prevent rattles.
Model f Go to
DS8S 4.3
All other models Continue
All models in the range except for the
DS8S may be bi-wired or bi-amplified. In
3-way systems, one set of terminals
feeds the bass drivers and the other the
midrange and tweeter. In 2-way systems,
one set of terminals feeds the bass/
midrange driver and the other the tweeter.
Separation of the signal paths to each
section of the speaker can improve
imaging and the resolution of low-level
detail, and allows the user to optimise
the cable to the frequency range of use.
Bi-wiring involves the use of two
separate 2-core cables from the same
amplifier, one to each pair of terminals.
This is the minimum we would
recommend, but should you prefer to
single wire, perhaps during the initial set-
up procedure or because you do not
want to see a multitude of cables in the
room, you must connect both positive
and both negative speaker terminals
together.
The ear is at its most sensitive in the
midrange, so we recommend that, when
single wiring, you connect the cable from
the amplifier to the terminals that directly
feed the midrange driver.
Bi-amplification goes a stage further and
involves the use of two separate power
amplifier channels for each speaker. It is
not the same as having a fully active
system, because the speaker's internal
passive crossover is still used.
If using bi-amplification, ensure that each
amplifier channel has the same gain,
otherwise you will change the balance of
the speaker. Check the absolute polarity.
Some amplifiers invert the signal, and a
mixture of different types may cause a
dip in the overall response. If you have a
mixture of inverting and non-inverting
amplifiers, reverse the polarity of the
connections from any inverting amplifier
to the speaker.
Bear in mind that, even though midrange
and, even more so, tweeter drivers can
(and only need to) handle less
continuous power than bass drivers, the
amplifier feeding them needs to have an
adequate voltage swing in order to
supply the short-term high-frequency
peaks in music without distortion. A high
voltage capability implies high power, so
it is not particularly desirable to have a
lower powered amplifier feeding the
midrange and tweeter than is used for
bass drivers.
Model f Go to
800D 4.2
All other models (not DS8S) Continue
On delivery, the two pairs of terminals are
electrically separate from one another
ready for bi-wiring. (figure 32)
For single wiring, short cables are
provided to link both positive and both
negative terminals together. Each cable
carries a spade connector at one end
and a 4mm banana plug at the other.
When single wiring, connect the cable
from the amplifier to the lower terminals
on 2-way systems (805S, HTM4S,
SCMS) and the upper terminals on
3-way systems.
On these terminals, use the opposite
type of connector on the link cables to
what you have terminating your main
cable. For example, if your main cable
terminates in spade connectors or bare
wires, use the banana plug end of the
link cables in the same terminals.
(figure 33)
f Go to section 5.
4.2 800D
On delivery, both positive and both
negative terminals are connected
together by link plates.
When single wiring, leave these links in
position and connect the cable from the
amplifier to the centremost pair of
terminals. (figure 34)
When bi-wiring or bi-amplifying, remove
the links after loosening the lower, larger
diameter terminal caps. (figure 35)
The 4mm hole in the end of the terminal
post features a collet that may be
tightened around a banana plug using
the upper, smaller diameter terminal cap.
f Go to section 5.
4.3 DS8S
In addition to the normal speaker
terminals, there is an additional pair of
screw terminals to operate an internal
12V relay that switches the speaker
between monopole and dipole modes
from a remote trigger. (figure 36)
You cannot use this facility if:
a Your processor does not feature a
12V trigger at all.
b Your processor only offers a simple
trigger that outputs a 12V signal when
the unit is switched on. This can only
be used to switch other equipment on
and off at the same time.
Some of the most expensive processors
allow you to assign a trigger to the type
of programme being played. They
recognise information on the disc that
distinguishes between movies and multi-
channel music. Others allow you to
assign triggers to different inputs; so if,
for example, you use a multi-channel
SACD or DVD-A player for music and a
separate DVD player for movies, you can
set up a trigger accordingly.
The relay in the speaker needs a certain
amount of current to operate, so check
the specification of your processor first
before proceeding. You will need to draw
45mA for each speaker you want to
switch.
The relay in the speaker only works when
the manual switch is set to the monopole
(•) position. If there is no voltage to the
trigger input, the speaker stays
monopole. If a 12V DC signal is present,
the relay overrides the manual monopole
setting and switches the speaker to
dipole mode. If you have the switch set
to the dipole (••) position, the trigger
feature will not work.
f Continue to section 5.