User manual B&W ACM 65 INSTALLATION

[. . . ] Do not mix portrait and landscape at left and right, as an imprecise stereo image will be created. The following sections give guidance on optimum positioning, but this may be modified in line with domestic constraints. Normal Stereo and Home Theatre Front Left and Right Applications (figure 2) The speakers should be positioned with the tweeters at a little above ear height. If the speakers are to be used low in the wall invert the speaker so the bass unit is uppermost. [. . . ] The spacing between them will depend on the size of the room and distance to the listeners. 5m (5ft) and the distance between them should not exceed their distance from the listeners. Having the speakers and listeners approximately at the corners of an equilateral triangle is not a bad rule to follow. If the speakers are placed too far apart, a hole-in-the-middle effect may become apparent. Too close and the panoramic effect will be lost, accompanied by a reduction in depth information. For Home Theatre Installations, the speakers should not be closer together than the width of the screen and their height should be approximately at centre screen height. Home Theatre Centre Channel Applications Theoretically, the best position for a centre channel speaker is behind the centre of the screen, but this can only be realised when using an acoustically transparent projection screen. In most cases the speaker will be positioned in a laterally central position either directly above or directly below the screen. All other things being equal, choose the position that is nearest ear height. However, if this leads to a below screen position, you should be careful to ensure that the speaker is not too close to the floor (see above) and that the sound will not be muffled by the later placement of furniture. Extra clips may be concentrated around areas of particular unevenness. Existing construction Method 2 (figure 5) This method uses the pre-mount box, but requires that the aperture has been cut fairly accurately. Feed the pre-mount box through the aperture and pull it forward so that the tabs pull on the back of the wall panel. If the tabs on any one side foul a stud, cut them off and drill and screw through the pre-mount box into the stud. Push fit 4 of the barbed L-shaped metal pegs into the slots at the center of each side so that the wall panel is nipped and the pre-mount box is held in place. Apply a strip of sealing compound or mastic to the back side of the wall frame lipping. 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. 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. Use a separate twin cable from the amplifier terminals to each pair of speaker terminals (figure 7). Correct polarity connection is even more critical in this case to maintain the frequency response of each speaker as well as the correct balance between left and right speakers. [. . . ] Correct polarity connection is even more critical in this case to maintain the frequency response of each speaker as well as the correct balance between left and right speakers. The use of separate cables can improve the reproduction of low-level detail by reducing interaction in the crossover and allowing optimum choice of cable for each frequency range. Always make sure all the terminal caps are screwed down tight, as otherwise they may rattle. failure to observe correct polarity will result in a loss of bass and vague imaging in a multi-speaker installation. [. . . ]