Bowers & Wilkins CT800 installation manual Running In and Ancillary Equipment, Ancillary equipment

Running In and Ancillary Equipment

Ancillary equipment Running In

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.

The performance of the speakers will change subtly during the initial listening period. If they have 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 speakers to achieve their intended performance will vary depending on previous storage conditions and how they are 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.

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