Bowers & Wilkins DM603 - Manual (Page 3)

I N T R O D U C T I O N
Thank you lor purchasing B&W OM600 Series speakers.
Since i(s foundation in 1966. the continuing philosophy of B&W has been the quest tor perfect sound reproduction. Inspired by
Ihe company's founder, Ihe late John Bowers, this quest has entailed not only high investment In audio technology and
innovation but also an abiding appreciation ot music to ensure that the technology is pul to maximum effect.
It is also our policy to make sure the advanced features pioneered on one product are incorporated into others we manufacture
DM600 Series systems have cabinets with rounded edges to reduce sound ditiraction (the re-radiation ot sound waves from
sharp edges that interfere with and blur Ihe direct sound from the drive units), incorporating woven Kevlah^ cone
bass/midrange drive units tor lowest coloration and maximum detinilion They also have alloy dome tweeters with magnetic
fluid cooling to ensure good deliniiion lo the limits ot Budibiilly and mainiain dynamics to high sound levels. All these features
were originally developed tor the acclaimed B&W 600 Senes systems and go towards Ihe realisation of fine transducers.
However, no matter how good the speakers themselves, they must work well into the listening room and time spent on the
installation process will reap the reward of many hours listening pleasure. Please read through this manual fully. It will help you
optimise the performance ot your audio system
B&W distribute to over SO countries world-wide and mainiain a network of dedicated distributors who wilt be able lo help should
you have any problems your dealer cannot resolve.
U N P A C K I N G (figure I)
Fold the top carton flaps right back and invert ihe carton and contents.
Liti the carton clear of the contents.
Remove the inner packing from the product.
4 spike feel and 4 lock nuts are taped in recesses in one polystyrene end iray
2 foam plugs of ditleronl porosity are located in the central recess ol one polystyrene end tray
We suggest you retain the packaging for future use.
C O N N E C T I O N S (figures 2 & 3)
Ail connections should be made with the equipment turned oft.
There are two pairs ol gold plated terminals at the back ot each speaker, one pair to ihe bass unit and one pair to the tweeter
(midrange and tweeter m the case ot OM604) which permit bi-winng or bl-ampiilicalion it desired On delivery, both pairs are
connected together by high-quality gold plated copper links for use with a single twin cable.
For single cable connection, connect either ol the positive terminals on the speaker (marked *■ and coloured red) to the positive
terminal on the power amplifier and negative (-. black) to negative (figure 2) Failure to observe correct polarity will result in
poor sound balance and image focusing.
When bi-winng Ihe speakers, loosen the terminal caps and remove the links. Use a sepárale twin cable from the amplifier
terminals lo each pair ot speaker terminals (figure 3) Correct polarity connection is even more critical In this case to maintain
the frequency response ot each speaker as well as the correct balance between left and right speakers. The use ot separate
cables can improve the reproduction ot low-level detail by reducing interaction In ihe crossover and allowing optimum choice
of cable lor each frequency range.
Always make sure all Ihe terminal caps are screwed down tight as otherwise they may rattle
When choosing cable, keep the total electrical impedance (out and back) below the maximum recommended in the
specification, tn particular, Ihe cable lo Ihe tweeter should have low inductance, otherwise the very high frequencies will be
atienuated. Ask your dealer lor advice, as ihe optimum cable wilt depend on ihe length required
P O S I T I O N I N G (figure 4)
Some experimentation with the position ol the speakers is well worthwhile to optimise the interaction between them and the
listening room. However, as an initial guide;
Do not tit the spike feet until you have found the best position lor the speakers
Place the speakers and the centre ot Ihe listening area approximately at the corners ot an equilateral triangle.
Keep the speakers at least 1 5m (5ft) apart to maintain lelt-righi stereo separation.
Keep tho speaker battles at least 0.5m (20in) clear ol walls. Having the speakers loo close lo walls increases the level ot bass
relative to the midrange and may give a boomy quality lo the sound.
F I N E T U N I N G (figure 5)
Before line tuning the installation, double check ihe polarity and security ot the connections.
II the level ot bass is uneven with frequency, this is usually due to strong excitation ot resonance modes in the room. Even
small changes In Ihe position of the speakers within the listening room can have a profound effect on the perceived sound
quality by altering tne excitation of these modes. Try mounting the speakers along a dilfetent wall. Even moving large pieces
of tumiiure about can have an effect
It the general level ot bass is too high, try moving the speakers further away from the walls. Conversely, it you need more bass,
move the speakers closet lo the walls Space behind the speakers also improves the impression ot perspective on well recorded
material
If you cannot move the speakers further from the walls, the bass level may be reduced by inserting one ot the foam plugs
provided Into the port tubes The higher ihe density ot foam used, the more the operation ot the port, and Iherofore the level
ot bass. IS reduced
If the central image
listening area
It the sound is too harsh, increase the amount of soft furnishing in Ihe room For example, use heavier curtains Conversely
reduce the amount of soft lurnishing It the sound is dull and lifeless.
Test lor flutter echoes by clapping your hands and listening lor rapid repetitions These can smear tne sound, but may be
reduced by irregular shaped surfaces such as bookshelves and large pieces ot furniture
Ensure the speakers stand firmly on ihe Moor Whenever possible lil the spike feet supplied after you have ophmised the
positioning These are designed lo pierce through carpeting to Ihe floor surface. Iniiiaily, screw the lock nuts fully onto Ihe
spikes and screw the spikes luliy into the threaded inserís in the base ol the cabinet It the cabinet rocks, unscrew the iwo
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