Before fine tuning, double check that all the connections in the installation are correct and secure.
Floor- and stand-mount speakers only
Moving the speakers further from the walls will reduce the general level of bass. Space behind the speakers also helps to create an impression of depth. Conversely, moving the speakers closer to the walls will increase the level of bass.
803D, 803S, 804S, 805S, HTM1D, HTM2D, HTM4S, SCMS only
These vented-box systems are supplied with foam plugs fitted in the ports. Normally, the speakers should be used with these plugs removed for maximum bass output, but if the bass is too heavy due to room effects and you cannot move the speakers further from the walls, refit the plugs to reduce the bass output. (figure 37)
If the bass is uneven with frequency, it is usually due to the excitation of resonance modes in the room
Even small changes in the position of the speakers or the listeners can have a profound effect on how these resonances affect the sound. Try positioning the speakers along a different wall. Even moving large pieces of furniture can have an effect.
For the most discerning listening, remove bass and midrange grilles as described in section 8 – Aftercare.
Tweeter diaphragms are very delicate and easily damaged. The tweeter grilles are held in place with magnetism and
any mishandling of the grille close to the tweeter may result in the grille being attracted into the tweeter diaphragm. For these reasons, we recommend that you leave tweeter grilles in place.
800D, 801D, 802D, HTM1D only
If you use these systems without the midrange grille, replace the plastic centre plug of the midrange drive unit with the solid aluminium plug in the accessory pack. Simply unscrew the fitted plug and screw in the replacement. Hand tighten only. (figure 38)
If the sound is too harsh, increase the amount of soft furnishing in the room (for example, use heavier curtains), or reduce it if the sound is dull and lifeless.
Test for flutter echoes by clapping your hands and listening for rapid repetitions. Reduce them by the use of irregular
shaped surfaces such as bookshelves and large pieces of furniture.
DS8S only
In monopole mode, the high-frequency output level may be adjusted using the top toggle switch on the front baffle.
(figure 39)
In the centre 0 position, the system response is nominally flat. The + position gives more output, which may be required, for example, if the acoustic of the room is dull, if circumstances dictate that the speakers have to be placed more off line than recommended, or if the speaker is built into custom furniture and placed behind fabric that is more absorbent than that on the grilles supplied. Conversely, the – position reduces the level for when the room acoustic is too bright or if you want to reduce your awareness of the speakers' location.
Experiment to find the mode settings best suited to your requirements. Typical combinations are:
•All surround speakers monopole.
•Side speakers dipole, rear speakers monopole.
•All surround speakers dipole.
It would be unusual, but not impossible, to set side speakers to monopole and rear speakers to dipole.
The performance of the speaker will change subtly during the initial listening period. If the speaker has been stored in a cold environment, the damping compounds and suspension materials will take some time to recover their correct mechanical properties. The drive unit suspensions will also loosen up during the first hours of use. The time taken for the speaker to achieve its intended performance will vary depending on previous storage conditions and how it is used. As a guide, allow up to a week for the temperature effects to stabilise and
15 hours of average use for the mechanical parts to attain their intended design characteristics.
However, longer run-in periods (as long as a month) have been reported and there is evidence to suggest that this has little to do with the speaker changing and more to do with the listener getting used to a new sound. It is especially so with highly revealing speakers such as these, where there may be a significant increase in the amount of detail portrayed compared to what the listener has previously been used to; the sound may
at first appear too “up front” and perhaps a little hard. After an extended period of time, the sound will seem to mellow, but without losing clarity and detail.
7 ANCILLARY EQUIPMENT
Speakers of this ability deserve signals of the highest quality. Choose your electronic equipment and interconnecting cables with care. We can give guidance on what to look for when choosing ancillary equipment, but cannot recommend specific items. The standards of such products are improving all the time and your dealer will be able to demonstrate a variety of suitable up-to-date products.
In the specification we recommend a range of amplifier powers. The higher figure is defined by the power handling capability of the speaker. When calculating the power handling, it is assumed that the amplifier is not run into clipping, which distorts the frequency power spectrum of the signal, and that the signal is normal programme material. Test tones from oscillators and the like are not applicable. The lower figure is the minimum we consider necessary to achieve reasonable listening levels without audible distortion in the smaller room (less than 60 m3 or 2000 cu ft). The higher the power you use, the less likely you are to experience amplifier clipping.
You can often tell how good an amplifier is at driving complex speaker loads by looking at its power rating into both 4Ω and 8Ω loads. The nearer the ratio is to 2:1 the better, as it indicates a good current capability.
In order to reduce the effect the cable has on the frequency response of the speaker to inaudible levels, the impedance of the cable at all frequencies (measuring both positive and negative conductors in series) should be kept as low as possible and certainly below 0.1Ω . At low frequencies, the DC resistance of the cable is the dominant factor and you should choose a gauge of wire sufficient to achieve the impedance requirements over the length of cable you need to use. At mid and high frequencies the inductive component of the impedance can dominate the DC resistance. This and other properties influenced by the detailed construction of the cable become important. Ask your dealer for advice on the best cable for your needs.
8AFTERCARE
Veneered cabinet surfaces usually only require dusting. If you wish to use an aerosol cleaner, remove grilles first by
