Limited Warranty, Stray Magnetic Fields | Bowers & Wilkins CT7.5 LCRS

Stray Magnetic Fields

The speaker drive units create stray magnetic fields that extend beyond the boundaries of the cabinet. We recommend you keep magnetically sensitive articles (CRT television and computer screens, computer discs, audio and video tapes, swipe cards and the like) at least 0.5m (20 in) from the speaker. LCD and plasma screens are not affected by magnetic fields.

Connections

All connections should be made with the equipment switched off.

CT700 Series speakers have a pair binding post connection terminals and one Neutrik® Speakon® connection socket on their rear panels. The binding post terminals provide quick and easy connection of stripped wires while the Speakon socket provides a more secure and reliable connection method.

If the binding post terminals are to be used, connect the positive cable to the red terminal and the negative cable to the black terminal. Incorrect connection can result in poor imaging and loss of bass. Figure 5a illustrates use of the binding post terminals

If the Speakon® option is to be used, disassemble the Speakon® plug as shown in Figure 5b, connect the positive cable to the terminal marked +1 and the negative cable to the terminal marked -1. Incorrect connection can result in poor imaging and loss of bass. Once the plug is reassembled it can be inserted into the socket and locked by twisting clockwise.

Ask your dealer for advice when selecting speaker cable. Keep its total impedance below the maximum recommended in the speaker specification and use a low inductance cable to avoid attenuation of high frequencies.

Neutrik® and the names of Neutrik® products referenced herein are either trademarks and/or service marks of Neutrik®.

Fine Tuning

Before fine tuning, make sure that all the connections in the installation are correct and secure.

If the bass seems uneven with frequency this will most probably be due to resonance modes in the listening room. Even small changes in the listening position can have a profound effect on how these resonances affect the sound. Try moving the listening position. The presence and position of large pieces of furniture can also influence resonance modes. If you want generally to reduce the volume of bass fit the foam plugs in the speakers’ port tubes as illustrated in Figure 6.

If the sound is too bright, increasing the amount of soft furnishing in the room (heavier curtains for example) may help balance the sound. Conversely, reducing the amount of soft furnishing may help brighten a dull sound.

Some rooms suffer from “flutter echoes” – echoes that “bounce” between parallel room boundaries. Flutter echoes can colour the sound of the speakers in the room. Test for flutter echoes by standing in the middle of the room and clapping your hands. Flutter echoes

can be reduced by placing irregular shaped items or non-reflective surfaces, bookshelves, rugs or pictures for example, on one of the offending walls or floor.

Running-in Period

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 of the drive units 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 the new sound. This is especially so with highly revealing speakers such as these where there may be a significant increase in the amount of detail compared with 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.

Aftercare

The cabinet surfaces usually only require dusting. If you wish to use an aerosol or other cleaner, remove the grille first by gently pulling it away from the cabinet. Spray aerosols onto the cleaning cloth, not directly onto the product. Test a small area first, as some cleaning products may damage some of the surfaces. Avoid products that are abrasive, or contain acid, alkali or anti-bacterial agents. Do not use cleaning agents on the drive units. The grille fabric may be cleaned with a normal clothes brush whilst the grille is detached from the cabinet. Avoid touching the drive units, especially the tweeter, as damage may result.