English
INTRODUCTION
Description
The Signature 8NT is a
The total design is divided into four separate modules:
1.Wall frame and grille
2.Baffle with drive units and crossover
3.PMK (Pre/post Mount Kit)
4.Back box
Separately packing each module enables parts to be stored safely off site until they are needed. The first two modules are required for all installations and so are delivered together in a master carton. See below in this section to find out whether you need either the PMK or the back box for your particular application. You will need one of them, but not both.
The speaker may be
Do not begin the work until you have thoroughly read this guide.
To get the best from the speaker, it is important that it is installed in a proper manner. We suggest you familiarise yourself fully with these instructions before starting any work. If there is any point you do not understand, help and advice is available from the appointed B&W distributor/importer in your country.
Installation options
Warning;
The speaker drive units create stray magnetic fields, which may affect televisions containing conventional cathode ray picture tubes. Keep the
1
speaker at least 50cm (20 in) clear of such devices. Some particularly sensitive televisions may require further spacing.
The Signature 8NT can be installed in drywall or solid construction in either vertical or horizontal orientation. With existing drywall construction, the speaker can readily be retrofitted in the vertical orientation. However, horizontal orientation requires cutting into vertical wall studs, so is a major job, more akin to new construction than normal retrofit.
The wall frame and grille
The wall frame is installed after final plastering, but before decorating. The grille mesh and frame may be painted as desired before the baffle and drivers are fitted.
The baffle
The baffle contains all the working parts of the system. Having it separate from the frame makes it easier to fit the frame and avoids possible damage to the drivers during decorating.
The back box
In drywall construction, the back box provides extra sound insulation between adjacent rooms and a safety barrier to the spread of fire between the wall cavity and the room. If you are working with solid walls, the back box gives a defined working volume that extends beyond the immediate area of the speaker itself. Any smaller volume and the speaker will have a restricted bass performance. For extra flexibility in installation, for example keeping clear of other objects in the wall, the speaker may be positioned either in the centre of the back box, or to one end. (Figure 16 )
The PMK
The PMK is used in drywall construction whenever the back box is not required, whether new construction or retrofit.
PLANNING THE SPEAKER POSITION
Overview
Consider carefully where the speakers are to be
placed in the room according to the application. The following are guidelines but, as with any custom installation, specific
The speaker may be installed in either vertical or horizontal orientation, the latter normally used for centre channel applications to allow positioning above or beneath the screen.
In order to maintain optimum horizontal dispersion through the upper crossover region and cover a spread of listeners, the centre portion of the baffle containing the midrange and tweeter should be rotated by 90º so that the drivers are positioned one above the other.
The summing axis of the midrange and tweeter is deliberately tilted 5º towards the midrange driver and this, together with the ability to rotate of the centre portion of the baffle, permits greater freedom when planning the vertical position of the speakers. If the speaker is to be mounted with its centre above ear height, turn the sub- baffle so that the tweeter is above the midrange. If it is to be mounted below ear height, have the tweeter below the midrange. Try to keep the centre within 10º of ear height for best results. Beyond 10º, a response dip at crossover will begin to develop, which will make the sound seem more recessed. Consider 15º the maximum to allow. (Figure 1)
In horizontal orientation, the speaker will cross normally spaced vertical drywall studs, so special stud construction will be required to give the necessary clearance, even if not using the back box.
2-channel audio
Aim to have the speakers and the front centre listener approximately at the corners of an equilateral triangle. The listening distance will then determine the speaker separation. If you are restricted, err on the side of having the speakers closer together to avoid the 'hole in the middle' effect. (Figure 2)
The height of the speakers should ideally be such that the centre of the baffle is within 10º of ear height.
Multi-channel left/right front
The angle between the speakers at the listener is normally less than for
The height should be chosen so that the centre of the baffle is as close to screen centre height as possible, while keeping within 10º of ear height.
Multi-channel centre front
If using an acoustically transparent projection screen, position the speaker as close to screen centre as possible, while keeping within 10º of ear height. Use vertical orientation.
In all other cases, orient the speaker horizontally and place it either immediately above or below the screen.
Multi-channel surround
Place the speakers with the centre of the baffle around 60cm (2 ft) above ear height to give a more diffuse sound than from the front speakers. For 5.1 channel systems, the two surround speakers should be positioned an angle of approximately 120º round from front centre. (Figure 3) For 6.1 EX systems, the two side speakers should be more forward than this, almost in line with the listeners. One speaker should be placed on the rear wall directly in line with the centre of the listening area. Alternatively two rear speakers may be used side by side, one either side of a stud in drywall construction. (Figure 4) For 7.1 systems, the two rear speakers should be further apart. A good guideline is for them to have an angular spread of about 40º to the listeners. (Figure 5)
