Bowers & Wilkins 704 S2 Floorstanding Speaker Review - AVForums
What is the Bowers & Wilkins 700 S2 Series?
The Bowers & Wilkins 700 S2 Series is the latest iteration of the company's middle range of speakers. It takes innovations first introduced in B&W's 800 Series and applies them to a more conventional loudspeaker design, and in a more cost-effective manner. As a result, the new speakers don't look vastly different from the outgoing CM Series, but there have been some significant changes inside.
For a start, the 700 Series uses a Carbon Dome tweeter that bridges the gap between the Aluminium Double Dome used on the 600 Series, and the Diamond Dome employed on the 800 Series. It also boasts the Continuum mid-range cone first introduced on the 800 Series, combined with a more affordable implementation of the Aerofoil cone found on the top-end model.
The 700 Series uses a new midrange decoupling system that is a simplified version of the one found on the 800 Series, while the floorstanders in the range also adopt tuned-mass dampers and an aluminium midrange chassis. There's an all-new protective mesh grille on the tweeter and a trim around the drive units that's inspired by the 800 Series and colour-coordinated to suit the overall finish.
The range comes in a choice Gloss Black, Satin White, and Rosenut – with the latter switching from a fully paint-filled finish to an open-grain wood finish. The range consists of the 702 S2, 703 S2, and 704 S2 floorstanding speakers; along with the 705 S2, 706 S2, and 707 S2 standmount models. There's also the HTM71 S2 and HTM72 S2 centre speakers.
For the purposes of this review, I was running a 5.1-channel system composed of a pair of 704 S2 flootstanders at the front, an HTM72 S2 as the centre speaker, a pair of 707 S2 standmount speakers for the rear surround channels, and a Bowers & Wilkins DB4S active subwoofer for the bass. That system will set you back £4,750 as at the time of writing (October 2018), which isn't cheap but if it lives up to B&W's claims it will be well worth it. Let's find out.
Bowers & Wilkins 704 S2 Floorstanding Speaker
The Bowers & Wilkins 704 S2 is a three-way, rear-ported, floorstanding speaker. It is composed of two 130mm Aerofoil Profile bass drivers, one 130mm Continuum midrange driver in a decoupled system, and a 25mm Carbon Dome tweeter. All three floorstanders in the range have an aluminium chassis that is stiffer than the zinc version used on the previous CM Series. There is also a tuned mass damper on the front face of the chassis, which is designed to dampen any remaining resonance within the cabinet.
As with all the speakers in the 700 Series, you have a choice of Gloss Black, Rosenut, and Satin White. There's a dark trim around the drivers and a magnetic black fabric grille on the first two, and a light trim with a grey grille on the white version. All of them have a grille mesh protecting the tweeter. A couple of minor gripes: the magnetic grilles can be knocked off really easily, and if you go for gloss black make sure you wear white gloves when handling them because that finish is a total fingerprint magnet.
The overall design of all the speakers in the 700 Series is clean and contemporary, with a gorgeous finish and a fantastic level of build quality. The wonderfully inert cabinets are extremely well-made, making a pleasingly solid noise when you tap them. There's definitely the feeling of a higher-end speaker, and you can sense the presence of the 800 Series in the DNA of the 700 Series. There are a few choices when it comes to the bottom of the 704, with rubber feet, M6 spike feet, and a plinth for added stability.
The B&W 704 S2 has a nominal impedance of 8 ohms, a claimed frequency response of 48Hz - 28kHz ±3dB, and a claimed sensitivity of 88dB spl (2.83Vrms, 1m). There are foam bungs included for tuning the rear bass ports and, in typical B&W fashion, the speakers can be bi-wired if preferred. Each speaker measures 925 x 165 x 277mm (HxWxD) without the plinth attached but including the grille and speaker terminals, and weighs 18.5kg. If you want to buy a pair of 704 S2s on their own, they'll cost £1,999.
Since there are three main innovations in the 700 S2 Series, I thought I address one with each of the three speakers. That way I can spread them out, rather than explaining everything while describing the 704 and thus leaving the text for the HTM72 and 707 a bit short. I'll start with the Aerofoil Profile bass driver, since only the 704 employs these and it has two of them.
This is a more affordable version of the Aerofoil cone employed in the 800 Series, and uses paper rather than costly carbon fibre skins. In addition, the sandwich filling material is EPS and not syntactic foam as used in the 800 Series. The result, according to B&W, is that the Aerofoil Profile drivers can deliver more accurate and powerful bass than previous designs, but are also more cost-effective.
The floorstanding 704 is beautifully designed and has plenty of the 800 Series in its DNA
Bowers & Wilkins HTM72 S2 Centre Speaker
The Bowers & Wilkins HTM72 S2 is a centre speaker with a 2-way, rear-ported cabinet that uses two 130mm Continuum midrange drivers and a 25mm Carbon Dome tweeter. The HTM72 offers the same choices of finish, the same mesh grille over the tweeter and the same magnetic fabric grilles as the rest of the range. There is a foam bung included for tuning the rear bass port, the option to bi-wire and four self adhesive rubber feet.
The build quality and finish are equally as impressive, and the B&W HTM72 S2 has a nominal impedance of 8 ohms, a claimed frequency response of 70Hz - 28kHz ±3dB, and a claimed sensitivity of 87dB spl (2.83Vrms, 1m). The speaker measures 167 x 480 x 260mm (HxWxD) including the grille and speaker terminals, and it weighs 9.11kg. If you want to buy an HTM72 on its own, it will set you back £599.
The second and biggest innovation is the Continuum cone, which is taken directly from the 800 Series. After an unprecedented eight years of development and 70 iterations, the Continuum cone was finally introduced into the 800 Series. Its design is based on the concept of optimised and controlled flexibility, which helps to avoid the abrupt transitions that can impair the openness and neutrality of a drive unit. This woven cone is strong and light but still retains the familiar dustup in the middle, even if the cone itself is a less familiar silver colour.
While it delivers an improved performance, it also continues the approach that B&W has been taking since first introducing the vivid yellow Kevlar cones that were synonymous with its speakers. The Continuum cone uses a woven composite (the exact materials are a closely guarded secret) that, like Kevlar, gives a highly controlled break-up at higher frequencies. While the Continuum cone may handle these higher frequencies better than Kevlar, in terms of B&W's intentions and approach there is a continuity to decades of research that effectively gives the material its name.
The HTM72 centre speaker has the same solid build and impressive specs as the rest of the range
Bowers & Wilkins 707 S2 Standmount Speaker
The Bowers & Wilkins 707 S2 is a standmount speaker with a 2-way rear-ported cabinet, a 130mm Continuum midrange driver and a 25mm Carbon Dome tweeter. Once again, the 707 offers the same finishes, mesh grille tweeter, and magnetic fabric grilles as the other 700 Series speakers. There are also foam bungs for tuning the rear bass ports, the option of bi-wiring, and eight self adhesive rubber supporting feet.
There's the same solid build and gorgeous finish, and the B&W 707 S2 has a nominal impedance of 8 ohms, a claimed frequency response of 50Hz - 28kHz ±3dB, and a claimed sensitivity of 84dB spl (2.83Vrms, 1m). The speakers measure 280 x 165 x 276mm (HxWxD) including the grille and speaker terminals, and they each weigh 6kg. If you want to buy a pair of 707s, they'll cost £799.
The final major innovation is the Carbon Dome, which is designed to bridge the performance gap between the Aluminium Double Dome used on the 600 Series, and the Diamond Dome found on the 800 Series. The Carbon Dome's first break-up performance is 47kHz, which perfectly positions it between the 38kHz of the Aluminium Double Dome and the 70kHz of the Diamond Dome.
The Carbon Dome is composed of two sections, with the front portion composed of a 30 micron aluminium dome that has been stiffened with a coating of carbon. The second section is a 300 micron carbon ring that has been profiled to match the form of the main dome. This is then bonded to the inner part of the structure, creating a tweeter with exceptional stiffness and residence to distortion but no undue mass.
You might well be thinking that since a human being can't actually hear frequencies that high, what's the point of pushing the performance out past 38kHz, let alone up to 70kHz. The reason is that, how a speaker performs at the higher end of the spectrum, even if it isn't actually audible, can cause aberrations at very high frequencies that can still affect the speaker's performance in the midrange, which we can hear.
The standmount 707 is a great performer on its own, making for a cracking surround speaker
Bowers & Wilkins DB4S Subwoofer
The Bowers & Wilkins DB4S is an active, sealed cabinet subwoofer with a 10-inch Aerofoil driver that's based on the 800 Series, and has 1000W of Class D amplification. There's a digital preamplifier with dynamic EQ, app-based setup, and a claimed frequency response of 10Hz to 350Hz. There are the same Gloss Black, Rosenut, and White Satin finishes as the 700 Series, with black magnetic fabric grilles for the first two and a grey grille for the Satin White.
In terms of connections, there are two RCA phono inputs and two XLR inputs, along with two 12V triggers and an RS232 connector for serial control. In terms of the positioning the subwoofer, you have the choice of spiked feet, decoupling feet, or rubber feet. The DB4S measures 377 x 360 x 368mm (HxWxD) and it weighs 26kg.
When I initially saw the back of the DB4S I was in for a bit of a shock – aside from the connections, there's nothing else. No controls, no settings, nothing. That's because Bowers & Wilkins has taken a similar approach to SVS, and uses a smartphone app to set up and control its subwoofers. In fact, B&W has gone further than SVS, by not having any controls or display on the sub itself, or even including a remote. That means you have to use the DB Subwoofers Bluetooth app (freely available for iOS and Android) in order to set up the DB4S. I guess B&W assumes everyone owns a smartphone these days, but in the unlikely event you don't... tough.
My iPhone paired with the DB4S as soon as I opened the app, and I found the entire setup process to be very easy and highly effective. The app allows you to set up the input (RCA or XLR), and the type of connection (none, stereo, or LFE). You can also adjust the input gain, select the input EQ (flat, music, movie, or custom), configure the stereo settings, and set the auto on and off functions. There's even an automated room equalisation feature, which uses the microphone in your smartphone to measure test tones that are played while you hold the phone on top of the sub and at seven other locations in the room. These measurements are automatically analysed, and an optimal room EQ curve is then applied.
The DB4S is a powerful subwoofer, but you have to use the excellent Bluetooth app to set it up
How was the 700 Series tested?
I tested the Bowers & Wilkins 700 S2 Series 5.1-channel speaker system in my dedicated home cinema. I positioned the 704 S2s at the front of the room on either side of my projector screen, I placed the HTM72 S2 centre speaker between them, and the 707 S2 standmount speakers were located at the sides and behind the main listening position. I placed the DB4S subwoofer at the front, away from the wall and firing forwards, and then tuned it for my room using the setup app.
I tested the B&W 700 Series 5.1 system with a mixture of material ranging from Blu-ray and Ultra HD Blu-ray, CD, DVD-Audio, SACD and music streaming. My primary source was the Oppo UDP-203 4K Blu-ray player, and for amplification, I used my reference Arcam AVR850 AV receiver in a 5.1-channel configuration. In addition, I also used the Denon AVC-X6500H AV amplifier that I happened to be testing at the same time as the B&W system.
The five speakers and subwoofer combined to create a superb 5.1-channel system
Performance
I have used B&W speakers for years, and until very recently I still had a 7-channel system in my home cinema that was built around the 600 Series with its distinctive yellow Kevlar drivers. So as I sat down to start testing the 700 Series, I thought I already had a pretty good handle on how a B&W speaker should sound. Boy, was I wrong.
It's fair to say that those earlier B&W speakers which used the company's traditional Kevlar drivers tended to have a distinctive sound. That's not necessarily a bad thing, and the midrange characteristics for which the speakers were famous had plenty of fans, myself included. The new Continuum drivers are an entirely different ballgame, with the 700 Series delivering the kind of precise and neutral performance that I wouldn't normally associate with B&W.
What that means is that where these speakers are concerned, what you put in is pretty much what you're going to get out. And when it comes to film soundtracks, that's exactly what you want. The sound designers have gone to great lengths to create a detailed soundstage, and so the speakers should simply replicate that as precisely as possible.
The floorstanding 704 S2s set the stage perfectly, with an authoritative performance that is both refined and detailed. However, they're also spacious, producing a big and open front soundstage that perfectly suited the widescreen cinematic vistas. There was plenty of bass as well that was nicely integrated with midrange, while those aluminium tweeters picked out the higher frequencies like a laser guided missile. As a result of this, the front left and right speakers had a tightness and immediacy that allowed them to deliver music and effects in equal measure.
Nestled between the two floorstanders was the HTM72 S2, with a solid presence that delivered precise and focused dialogue. It combined with the left and right channels to create a compelling front soundstage, placing effects across the screen, and drawing you into the action. The tonal balance wasn't perfect, but then you would only get that if the speakers were identical, but there was still a nice sense of cohesion. This was expanded with the addition of the 707 S2 standmount speakers at the rear, creating a 360˚ sound field around which effects could be steered.
The five speakers worked in unison, creating a pleasingly accurate soundstage that, while suitably neutral, also retained a degree of excitement as well. The size and solid nature of the speakers themselves resulted in a strong bass presence that anchored the entire system around the listener. The DB4S then came in and delivered the low-end extension like the proverbial sledgehammer. The 10-inch driver and 1000W of amplification energised the room with low frequencies that supported and enhanced the rest of system.
The recently released 4K discs of X- Men and X2: X-Men United both include excellent 5.1-channel DTS-HD Master Audio soundtracks. So I took the opportunity of listening to them with the 700 S2 system, and the results were an absolute blast. The speakers delivered Patrick Stewart's opening monologue in both films with exceptional precision, before launching into the rousing main theme, which was rendered with a real sense of passion.
As Wolverine moved around the deserted mansion in the first film, Charles Xavier's voice can be heard from different speakers. The effect was seamless, and the voice was accurately reproduced each time. The attack on the same mansion in the second film was handled with a similar combination of precision and excitement, creating a highly effective sequence. The sounds of helicopters and gunfire were delivered with an audible impact, as was Wolverine's berserker charge through the troops sent to kidnap the school's students.
The sequence at the climax of the first film, where Magneto is using the Statue of Liberty to transform the leaders of the world into mutants, features a magnetic field that spreads out. The sound moves with it, and fills the room as it rolls from the front speakers to the rears. In the second film, Wolverine's fight with Lady Deathstrike involves plenty of slashing, stabbing, and Adamantium claws tearing through metal. The 700 Series delivered all these effects with a visceral precision that made the fight sound as brutal as it looked.
I then moved on to a couple of my favourite test discs, starting with the opening bass note from Edge of Tomorrow. The entire system was impressively energised with low frequencies, before the DB4S took over and plumbed the depths of its range. The opening car race in Ready Player One is a very detailed and aggressive sound mix, that this 5.1 system handled particularly well. The numerous effects were steered around the room with precision, while Kong's appearance contained a frightening amount of bass. However, within this surround sound cacophony, the dialogue always remained intelligible.
I particularly enjoyed watching Sicario 2: Soldado, which offered plenty of opportunities for the 700 Series to show its full capabilities. The dialogue was always delivered with a clear precision, even if Benicio Del Toro does have a tendency to mumble. The numerous helicopter sequences were rendered with a realistic low-end rumble, whilst the explosions had plenty of impact. The gunfire was also impressive, with the B&Ws delivering the high-frequency sound of falling shell casings, while also giving the ordinance a percussive kick.
One thing that I did notice was that the performance was more impressive with the Arcam, than it was with the Denon amplifier. In part, the Arcam is simply better, with superior amplification, and a higher price tag. But it's also fair to say that to get the best from these speakers, they should be paired with amplification that can really drive them to their full capabilities. A less capable amplifier might struggle to get the very best from the 700 Series, but with the Arcam AVR850 they were a sonic joy.
The 700 S2 Series delivers the kind of precision and passion that works perfectly with movies
Conclusion
Pros
Superb performance
Excellent build quality
Attractively designed
Cons
Can be demanding to drive
Bowers & Wilkins 700 Series Verdict
The Bowers & Wilkins 700 S2 Series is fantastic speaker range, that combines beautifully designed and well-made cabinets with a host of innovations that have trickled down from the flagship 800 Series. The new Continuum cone is particularly effective, but the Carbon Dome tweeter and Aerofoil Profile bass driver play their part too, resulting in speakers that are significantly more neutral than previous B&W models. However, they also retain a sense of excitement and joy, that is so important when dealing with speakers aimed at the home rather than a post-production facility.
The 5.1 system worked as a genuinely cohesive unit with the floorstanders, centre speaker, and standmounts delivering a lovely tonal balance. The high frequencies were delivered with precision, the midrange was particularly well-defined, and the bass had plenty of presence that was ably assisted by the DB4S subwoofer. As a result, music was beautifully rendered, effects precisely steered around the room, and explosions delivered with real impact. The system engaged me at an emotional level, and that's about as much as you can really ask for from a set of speakers.
The 700 Series performs best when partnered with amplification that has the grunt to really push them, getting the best from what is an extremely capable range of speakers. There's no doubt that Bowers & Wilkins research and development hasn't been wasted, with the 700 S2 Series offering a sense of the performance found on the flagship 800 Series but at a relatively affordable price. You'll struggle to find a better all-round set of speakers for the money, and the B&W 700 S2 Series 5.1 system comes highly recommended.