Planning the installation, Safety Warning

Planning the installation

Figure 1

Figure 2

Figure 3

~120o

Figure 4

~40o

Safety Warning!

A CT800 system is capable of producing very high sound pressure levels. Prolonged exposure to high sound levels can lead ﬁrst to temporary and later permanent hearing damage. Do not exceed recommended Leq (equivalent sound level) exposure levels, for example, those speciﬁed in ISO 1999:1990.

Check the contents against Figure 1

Planning the installation

Because of the built-in nature of the installation, the planning stage is of the utmost importance. Any need to adjust speaker position, for example, is a much more involved process than with free-standing speakers. Care must also be taken to construct proper support for the speakers. It is all too easy to induce the panels of custom furniture to vibrate and colour the sound unless precautions are taken to prevent it.

Speaker Position

Figures 2 to 4 show the recommended locations in plan view for the main speakers in 5.1, 6.1 and 7.1 channel installations. Some dimensions are marked ~, indicating that there is some latitude allowed each side of the ﬁgure, and some have a recommended range for optimum results. Subwoofers should be placed close to the main speakers to which they are assigned.

For successful operation of the surround speaker, CT8 DS, in dipole mode, it is important that all listeners sit within the speaker’s null zone. This is the 60o wide zone of low direct sound level created by the opposing polarity drivers on each side. You will notice from ﬁgures 3 and 4 that for 6.1 and 7.1 systems, the side speakers are shown in line with the centre of the listening area. This is suitable regardless of whether these speakers are used in dipole or monopole mode. However, for 5.1 systems, the two surround speakers should be placed somewhat behind the listeners for effective results in monopole mode, or if you wish to switch between monopole and dipole modes for different types of programme. If you only ever intend to use them in dipole mode, the two surround speakers should revert to the in-line position. Please read the discussion on surround modes in the next section for a clearer understanding of the beneﬁts of each type.

For larger audience sizes, a more even coverage of the surround sound ﬁeld may be obtained if the surround speakers are elevated above ear height, as in a commercial cinema. In that case, the speakers may be raised so that the midrange/tweeter array is approximately 60cm (2 ft) above seated ear height.

For correct operation of the CT8 DS in dipole mode, it is important not to obstruct the side ﬁring drivers. The speaker should be mounted with at least the front portion containing the side-ﬁring drivers protruding into the room and any customised covering should be acoustically transparent.