User manual B&W CDS6

[. . . ] These surround speakers conform to the specifications of Lucasfilm Home THX and differ from most conventional speakers in that they have a dipolar radiation pattern. The sound is projected mainly backwards and forwards, with drive units mounted on opposite sides of the cabinet. sound radiated in one direction has the reverse polarity to that radiated in the opposite direction. [. . . ] N e w C o n s t r u c t i o n (figure 2) Fit the separately available pre-mount kit - PMK8-to the studding before the drywall panels are fitted, following the instructions supplied with the kit. The drywall panels should be fitted up to the pre-mount box and plastered over. Screw, but do not tighten, 6 of the screws plus washers provided through the slots in the wall frame into the pilot holes in the pre-mount box. Mark along the inside edges of the slots and cut out the aperture neatly. Screw, but do not tighten, sufficient of them via the holes in the rear surface of the wall frame to ensure that it sits properly on the wall surface. A certain amount of flexing of the wall frame is allowed to take up unevenness in the wall surface, but do not over tighten the screws as excessive distortion of the frame may impede the fitting of the baffle. The wall frame is pre-finished in white primer paint, ready if necessary to be re-finished to match your own decor. Check the contents: 2 x Baffle with drive units, crossover and foam 2 x Wall frame 2 x Loudspeaker grille 1 x Alignment template 1 x Accessory pack containing: 20 x Spring clips + self tapping screws + washers 8 x Machine screws (fixing baffles to wall frames) We suggest you retain the packaging for future use. Remove the grilles and baffles from the wall frames and, to avoid damage, keep them in their plastic bags (and preferably in the carton) away from the work area until you are ready to fit them. To ensure the correct dipolar sound field, the speakers are handed left and right. When each speaker is positioned at the correct side of the room, the positive terminal (coloured red) is nearer the screen. Failure to observe correct polarity will result in ill-defined panning of sounds and strange phase effects. When choosing cable, keep the total electrical impedance (out and back) below the maximum recommended in the specification. Ask your dealer for advice, as the optimum cable will depend on the length required. NOTE: Certain power amplifiers cause a polarity reversal between input and output. (figure 1) Always mount the speakers with the midrange/high-frequency units pointing towards the front and rear walls. [. . . ] Check that there is no debris that may fall into the speaker (especially in ceiling mount situations). 5kHz 85Hz - 8kHz ±3dB power averaged over front hemisphere Horizontal: Figure-of-eight dipolar 250Hz - 12kHz 89dB spl (2. Reserves the right to amend specifications without notice in line with technical developments. [. . . ]