Bowers & Wilkins ISW-4 In-Wall Subwoofer & Amp

Bowers & Wilkins ISW-4 In-Wall Subwoofer & Amp

Free UK Delivery

On Demo


Bowers & Wilkins ISW-4 In-Wall Subwoofer & Amp

Their range of in ceiling, in-wall and outdoor speakers follow this design philosophy and often incorporate truly innovative quirks and features

The ISW-4 is one of Bowers & Wilkins most innovative products and enables the home audio or music enthusiast to experience a liquid, audiophile standard of bass response, while also having the luxury of not having to see where it comes from. It's an in-wall subwoofer, that features two large, long-throw 200mm drivers, capable of moving large volumes of air at an outstanding speed, allowing for a deep and controlled low-frequency output. 

The ISW-4 required its dedicated 250W Class D amplifier in order to work, this is called the SA250 Mk2, and together, the units produce an outstanding level of immersive low-frequency sound. 

Who are Bowers and Wilkins?

Bowers & Wilkins are a world-famous name within the hifi community and industry, has developed a vast number of loudspeaker models throughout the years and, winning the hearts of audio lovers and critics alike. B&W specialise in maintaining the balance between sound quality and price point, meaning that value for money and true quality is always at the forefront of the company's design process. 

Sold as a single unit - includes a required SA250 amplifier

 Description In wall subwoofer system
with external rackmount amplifier
 Drive Units 2 x 200mm (8 in) Paper/Kevlar® cone
 Frequency Range (-6dB) -6dB at 17Hz and 290Hz adjustable (EQ at A)
Frequency Response ±3dB 21Hz - 200Hz adjustable (EQ at A)
Bass extension -6dB at 17Hz (position A)
-6dB at 21Hz (position B)
-6dB at 24Hz (position C)
Power handling 200W 8Ω (minimum 6.3Ω)
Dimensions Height: 485mm (19 in)
Width: 255 (10 in)
Net weight 6.4kg (14.1lb)
Finish Frame/Grille Semi-matt white suitable for customising or pre-painting 
Accessories Pre-mount kit for new construction 
Backbox Height: 1406mm (55.4 in)
Width: 345mm (13.6 in)
Depth: 85mm (3.4 in)
Box net weight 9.6kg

Providing your item is in stock, the order is usually dispatched within 24 hours. Please remember that postage and packing is completely free for orders over £50*. Out of stock items will be dispatched as soon as they become available, out of stock items can take between 4 to 21 days for dispatch.

Deliveries usually take 1-3 working days. The majority of orders are sent via our couriers'; Interlink Express on a next-day-delivery service. Smaller, low value or light-weight items are normally posted using Royal Mail Recorded or Royal Mail Special Delivery.

Once your product has been dispatched, you will be notified via email and sent a unique consignment number, you can use this number at to check the status of your delivery. If you have provided a mobile telephone number, Interlink's Predict service will notify you by text (and email) of a one-hour delivery window. If the window they suggest is inconvenient, you can change the date of delivery to a later one via text or email.

*We ship free of charge to mainland UK addresses, excluding the Scottish Highlands or 'Out-Of-Reach' Scottish locations. Please consult the post-codes below to see if your location falls within this category. If you are still unsure, please contact us on 01432 354921. We also ship to Northern Ireland, Channel Islands, Scilly Isles, Scottish Isles and Scottish Highlands, however delivery to these locations will incur a charge and can only be sent via a 2-day service.

Shipping CostsMainland UK (Next-Day)Offshore/Out-of-reach (2-day)Northern Ireland, Channel Islands, Isle of Man, Scottish Islands, Scilly IslandsRepublic of Ireland (2-day)
Under £50 Orders £7.50 £12.50 £15.00
Over £50 Orders FREE £19.99 £29.99
Surcharge Orders £50.00 £69.99 £79.99
Saturday Delivery £12.99 N/A N/A
Sunday Delivery £12.99 N/A N/A


Post codes exempt from the free delivery service include:

Scottish Highlands Post Codes: AB30-38, AB41-42, AB44-56, FK17-99, G83, IV1-28, IV30-39, IV52-54, IV63, KW1-14, PA21-33, PA34-40, PH15-26, PH31-41, PH49-50
Islands Post Codes: HS1-9, IV40-51, IV55-56, KA27-28, KW15-17, PA20, PA41-49, PA60-78, PH42-44, ZE1-3
Northern Ireland: All BT postcodes
Channel Islands Post Codes: JE, GY
Scilly Isles Post Codes: TR21, TR22, TR23, TR24, TR25

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