User manual B&W 800 ASW

[. . . ] Rigid diaphragms are best for reproducing bass frequencies and this new construction allows us to thicken the cone section, without suffering increased mass. The extra thickness makes the cone a more effective barrier to any residual sound generated inside the cabinet, giving tremendous dynamics and timing to the bass, with the secondary effect of cleaning up the midrange. The FST midrange drive unit receives a new chassis ­ stronger, yet maintaining the maximum open area behind the diaphragm to minimise reflective obstruction and allow the free flow of air. They're difficult and expensive to manufacture, but they take the response all the way to 80kHz in a smooth manner, superior to most socalled supertweeters. [. . . ] (figure 25) Lay the speaker down on its side (to avoid possible damage to terminals or drive unit diaphragms). 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. The speakers may be fixed to a wall or ceiling using screws in the range 5mm to 6mm diameter (No. The screw head should be inserted into the round part of the aperture and slid fully along one of the slots. The slots are sprung loaded to prevent the speaker being readily knocked out of position. The screw length should be chosen to give a minimum of 25mm (1 in) engaged thread. This is the minimum we would recommend, but should you prefer to single wire, perhaps during the initial setup 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. 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. 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. [. . . ] We have chosen the finest wood veneers for the surface of the cabinet, but please be aware that, like all natural materials, the veneer will respond to its environment. Keep the product away from sources of direct heat such as radiators and warm air vents to avoid the risk of cracking. The wood is treated with an ultra-violet resistant lacquer to minimise changes in colour over time, but a degree of change is to be expected. This effect may be particularly noticeable where the area covered by the grille, or areas kept in shadow, change more slowly than other areas. [. . . ]