Bowers & Wilkins 805S, HTM4S, HTM3S, HTM1D, HTM2D 4CONNECTIONS, Important safety notice, 800D, DS8S

4CONNECTIONS

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)

fGo 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.

fGo 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:

aYour processor does not feature a 12V trigger at all.

bYour 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.

fContinue to section 5.

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