BOWERS & WILKINS ISW-4 (01) PDF Document

The product is shipped in three cartons. In addition to the Driver Panel, the BOWERS & WILKINS ISW-4 carton contains:

1 x Wall Frame

1 x Grille

1 x Cut-out template

1 x Adhesive B&W logo

1 x Paint mask

6 x M5 bolts

1 x Frame Gasket

In addition to the Back Box itself, the Back Box Carton contains:

1 x Installation Instructions

1 x Gasket roll

4 x Brackets

12 x M5 bolts

12 x special washers

12 x locking washer

Best results are usually obtained if the subwoofer is placed between the left and right speakers or in the vicinity of one of them. If two subwoofers are used, it is best to put one near the left and one near the right speaker.

Locating a subwoofer on one side wall of the listening room, even behind the listening position, is also possible but generally results in inferior imaging.

Positioning subwoofers near corners often generates more low-frequency room resonances, making the bass more uneven with frequency, though it increases volume.

Using multiple subwoofers can improve performance by maintaining stereo separation to the lowest frequencies, smoothing out the effects of low-frequency room resonances, and enabling a higher maximum sound output.

The BOWERS & WILKINS ISW-4 is intended for installation within new build drywall (stud wall) or solid construction (brick or block-work) walls. Installation must begin before plaster and/or sheetrock is applied.

It is possible to install the subwoofer in an existing drywall, but the amount of subsequent wall re-build may make such an exercise impractical.

Ensure the wall studding is properly prepared so that there is sufficient clearance for the Back Box and its cable entry gland. The Back Box is intended to fit between two adjacent wall studs on standard 40cm (16 in) spacing. A cross brace should be positioned directly above the subwoofer. The subwoofer driver aperture should be located at the bottom.

Attach two bracket components to each end of the box using six M5 machine screws, plain washers, and locking washers per pair of brackets. Do not fully tighten the screws at this stage.

Position the right-angle ends of the brackets outboard of the sides of the Back Box so they line up with the inside surface of the wall studs.

Position the Back Box in the wall and screw or nail the brackets to the wall studs. Use a spirit level to ensure the box is vertical in both planes and tighten the bolts securing brackets to the Back Box.

The Back Box should be built into the brick or block-work in a similar manner to a window frame. The brackets, bolts, and washers supplied will not be required. Care must be taken to avoid the Back Box rattling against the wall; it should be wedged in position to provide a clear gap all round.

If the Back Box is to be settled onto the lower course of bricks, use a flexible mastic rather than cement or mortar. Remember to leave clearance for the connection gland and cable. A suitable lintel must be used as the Back Box is not designed to take the weight of the wall above.

With the Back Box fitted in the wall, the cable from the CDA-4D amplifier can be routed through the wall and into the Back Box via its cable entry gland. Pull around 20cm (8 inches) of cable through the gland.

Secure the cable so that it cannot rattle against the studding or drywall panels and tighten the gland around the cable.

The back box should be covered with sheetrock (plasterboard) followed by a plaster skim. Sheetrock adjacent to the Back Box should always be fixed with generous beads of mastic to ensure that no audible vibration occurs.

The sheetrock extending over the front of the Back Box must have a hole cut accurately to the necessary profile using the cutting template as a guide. Apply the supplied gasket strip around the subwoofer hole in the back box.

Apply sheetrock over the entire front of the Back Box securing it with a generous bead of mastic. Once the aperture has been cut, the entire wall can be plaster skimmed. Once dry, use a vacuum cleaner to remove any dust and debris from inside the Back Box.

Rotate the “dog clamps” on the underside of the Wall Frame so they are oriented inwards and insert the Wall Frame into the Back Box so that the flange is flush with the plaster surface.

Tighten the dog clamp screws so that the frame is held securely and flat against the wall. Tighten opposite dog clamp screws in turn.

Ensure that the connection cable within the Back Box has not been trapped. Position the Frame Gasket within the frame perimeter; it is held in position through interference fit around the screw bosses.

Strip 15mm of insulation from the connecting cable within the back box and connect it to the spring-loaded connection terminals on the rear of the Driver Panel. Ensure connection polarity is correct (positive cable to red terminal, negative cable to black terminal).

Seat the Driver Panel within the Wall Frame and secure it with the six bolts supplied. Tighten opposite Driver Panel bolts in turn so that it is pulled flat into the Wall Frame.

Once fitted, the grille can be push-fitted in the slot between the panel and the Wall Frame. If painting is required, paint the grille before fitting.

Yes, the subwoofer’s drive units create stray magnetic fields that extend beyond its boundaries. It is recommended to keep magnetically sensitive articles (CRT television and computer screens, computer discs, audio and video tapes, swipe cards, etc.) at least 0.5m (20 in) from the speaker. LCD and plasma screens are not affected by magnetic fields.

Allow up to a week for the temperature effects to stabilize and 15 hours of average use for the mechanical parts to attain their intended design characteristics.

Longer run-in periods (as long as a month) have been reported, and after an extended period of time, the sound will seem to mellow without losing clarity and detail.