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Bowers & Wilkins 603 S3

Want a big, powerful pair of speakers with heavyweight bass and no shortage of definition and detail? Look no further than the 603 S3, the largest model in the latest iteration of the ‘entry-level’ 600 series from Bowers & Wilkins. With their duo of bass drivers, plus midrange and treble technology derived from speakers further up the company’s range, these are ideal speakers for larger rooms or use as part of a home cinema systems – there’s a matching centre speaker, the HTM6 S3, and the little 607 S3 model make a good surround speaker in multichannel set-ups – but they’re also controlled enough for those who just want a huge sound in more modest spaces.

But there’s a couple of things you have to realise about this design, the only floorstander in the new 600 Series: first is that, while they may look huge in pictures, they actually stand just over a metre tall, so they’re compact enough to fit in almost any room, taking up little more space than the 606 S3s on their dedicated stands, while the choice of black, white or light oak finishes means they’ll fit in with a wide range of décors. Matching grilles are provided to cover the drivers if required, in grey for the white or oak finishes, or black for the black version.

Second, don’t be fooled by that ‘S3’ suffix: the 600 series has been around, and continually upgraded, since 1991, and this is actually the eighth generation of this range, now slimmed down to those two standmount models and these floorstanders.

And the upgrades here follow a familiar pattern for the Worthing-based speaker company, with technology trickled down from the latest 800 Series flagships via the midrange 700 Series. The new titanium dome tweeter sits behind a more open mesh protector, first designed for the company’s Signature models, for crisper, cleaner treble, and has a version of the Nautilus tube, used to absorb unwanted energy from the rear of the driver for purity and focus. 

Meanwhile the midrange is in the hands of the same kind of Continuum cone driver you’ll find handling the same duties in the mighty 801 D4 Signature model – it’s designed and made in-house, using a woven cone that’s still a closely-guarded secret. Add in a pair of bass drivers to deliver low-frequency extension and speed, and you have a fine full-range design for all kinds of music, and one that’s easily driven by even quite modest amplifiers, thanks to high sensitivity and an easygoing load: the company says these speakers can be used with amplifiers with as little as 30W per channel. Mind you, they’re an absolute riot when used with some hefty amplification…

A stabilising plinth is packed with each speaker, and is quickly bolted in place following the instructions printed on the box – a nice touch –, though some help in unpacking the 603 S3s is probably a good idea, as they weigh 27.5kg apiece, and the assembly requires the upending of the carton once the plinth is fitted.

A two-piece foam bung for the rear-venting bass tuning Flowport allows the low frequencies to be tightened up if the speakers have to be used close to the wall behind them: it combines an outer foam ring for mild attenuation with a central core usable to increase its effect, making it possible to adjust the speakers for just about any position. As a benchmark, about 50cm away from side and rear walls is a good starting point, with the speakers 1.5-3m apart, and you might find a slight angle towards the listening position will help firm up the stereo image, especially if the speakers are close to side walls. How much you use the foam bung system is a matter of taste, so it’s worth experimenting with, especially if you find the bass a bit slow or overbearing in your room.

However, bear in mind that the speakers will initially sound a bit ‘tight and light’, especially if they’ve been stored or transported in low temperatures: give them a week or so of use to loosen them up before making any final decisions about positioning or the use of those bungs.


Straight from the boxes the 603 S3 speakers impress, with a big, bold presentation and the sense of a focused, detailed soundstage. Over that first week of running there’s a subtle filling-out of the bass without every straying into looseness, and the drivers ‘come together’ to deliver an entirely convincing sound, not least due to the S3s’ design bringing the treble and midrange drivers just a little closer together for greater integration. Yes, the underlying balance is warm and rich, but the fine control of all that weight, allied to the clarity of the upper frequencies, is never less than entirely satisfying.

As mentioned, these speakers will work well without huge power, as was clear when they were driven by an original Naim NAP 250 power amp of circa 1990 vintage, delivering 70W per channel, this enabling them to reach deep with bass-heavy music or the scale of a symphony orchestra, as well as delivering an open, fresh, and involving midrange and treble with excellent detailing in voices and instruments. However, things got either very silly or totally thrilling when the Michi X3 Series II integrated amp, rated at 200W into the speakers’ nominal 8ohm impedance – but capable of an awful lot more! – was pressed into service. The Michi series has been a Bowers & Wilkins favourite for demonstrations for a while, and it’s not hard to see why: the X3 SII, which is both the baby of the range and its absolute star, just has a way of getting hold of these speakers and driving them hard with absolute control. No, it's not just a matter of going really loud, though this set-up will undeniably do that to way beyond neighbour-worrying levels, and with not a sign of stress, but rather the way the dynamics and speed of music are delivered. From the instantaneous transition from a quiet orchestral passage to a great stab of brass, to the way driving rock music is delivered without losing track of the finer details of what all the band-members are contributing, the 603 S3 speakers impress. 

Even with small-scale music of the ‘audiophile jazz’ kind, or the more low-key tracks on the recently remastered Beatles ‘red and blue’ compilations, the easy delivery of detail and the way mixes are opened up are completely captivating. Give the speakers that slight ‘toe-in’ towards the listening position and they’ll not only give a solid, three-dimensional soundstage, but populate it with realistically-scaled instruments and voices, and locate them with great stability. Whether with a jazz trio, a constructed studio image or an orchestra laid out before the listener, the effect is always involving and totally natural-sounding.


Unless you have a truly tiny room, meaning they’ll have to be shoved into corners while you sit just a few feet away from them, the 603 S3 speakers have more universal appeal than that ‘larger rooms/home cinema systems’ description might suggest. With some care about positioning, and judicious use of those port-tuning bungs, they’re easy to accommodate, and will deliver a truly full-scale sound across a wide range of musical genres.


As with the smaller models in this latest ‘S3’ iteration of the 600 Series, the Bowers & Wilkins designers and engineers have again raised the bar with the 603 S3; the speakers are reassuringly solid, impeccably finished and sound every bit as good as their price-tag would suggest. Whereas some previous 600 series models flattered the electronics with which they were used to the extent of sounding a bit on the safe side, these new floorstanders retain the characteristic warmth without losing sight of everything else going on in a recording. And that makes them not just a very safe buy if you want full-scale music, but something of a bargain.


The Beatles Norwegian Wood (2023 mix)

Taken from the latest release of The Beatles 1962-1966 ‘red album’, this is just of the new mixes that open familiar tracks wide, showing the artistry of both performances and production – something the 603 S3 speakers make exceptionally clear

Espen Berg Trio 1914

Water Fabric, the latest ECM label outing by jazz pianist Espen Berg, finds his trio augmented by an array of guest musicians, giving tracks like this not just intricate detail but big dynamic swings, all of which plays to the 603 S3s’ strengths

Prokofiev Symphony No 5

Another of those excellent own-label London Symphony Orchestra releases, this time under the baton of Gianandrea Noseda, this account of the 1944 symphony is packed with detail, lyricism, and dramatic dynamics, delivered with gusto by the 603 S3 speakers

What the press say

Why you should buy it

A lot of effort has clearly gone into the 600 S3 series, and it pays off in a range-topping speaker design more than able to be used with modest amplification, but with that admirable ability to grow as you upgrade your system electronics. Add in the compact dimensions and room-friendly appeal, and the case for these speakers is pretty compelling.

Video review

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