But it was only a matter of time before the system trickled down to another BMW range with a bigger pool of potential customers. So, this flagship audio set-up is now available for the 5-Series, one of the most popular saloons on the planet.
Like the original 7-series system, this set-up features 16 speakers powered by a 10-channel, 1400W, Class D amplifier. Both front left and front right speaker configurations boast Bowers & Wilkins’ trademark Diamond tweeters – ultra thin, ultra rigid diamond domes usually reserved for B&W’s flagship stereo speakers.
Behind each one, you’ll find a diffuser designed in a spiral shape – a design idea inspired by Bowers & Wilkins’ high-end Nautilus speaker. Its job is to absorb and dissipate any sound from the rear of each tweeter.
Unlike some of B&W’s in-car speaker systems designed for Volvo and McLaren, the 7-Series system doesn’t use the company’s tweeter-on-top technology – a distinctive design with a tweeter mounted on top of the centre of the dashboard, firing straight into the cabin.
The 5-Series system makes do with a more traditional design. Here, the centre channel (an aluminium tweeter and Kevlar midrange driver combination) fires straight up from the centre of the dashboard.
Kevlar isn’t just good at stopping bullets. The material has been a trademark ingredient of B&W loudspeakers for decades, and there are seven Kevlar midrange drivers dotted around the 5-Series cabin.
You can spot the midrange drivers and tweeters a mile off – they’re placed behind beautifully etched stainless steel grilles and their presence highlighted by some subtle illumination in the front and rear doors. Bass is delivered by two 22cm subwoofers hidden beneath the driver and passenger seats.
It’s worth noting that the speaker layouts for the saloon and Touring versions of the 5-Series differ slightly. In the saloon, the rear surround speakers are positioned on the parcel shelf, while the Touring model sees them bumped into the rear roof lining.
At the heart of every BMW lies iDrive, the company’s much-lauded infotainment system. The 5-Series uses iDrive 6, the latest version of the set-up, which includes a 10.2in display which runs in landscape along the top of the dashboard. It’s a touchscreen so you can navigate using a finger, but when driving, the circular controller and shortcut buttons in the centre console are likely to get the most use.
Our test car is fitted with BMW’s Premium Package (£1820), which includes a special ceramic finish on the main controls for a more luxurious feel. Not vital, but it does feel much more tactile than the standard plastics. The display is smooth to operate – not quite up to Apple iPad standards, but it’s much more responsive and boasts less lag than than some rival set-ups.
The main display is made up from six tiles (you can see three at any one time) which you can scroll between. You can customise and reorder them by pressing, holding and dragging, just like shifting apps around an iPhone screen.
Opt for BMW’s Technology Package (£1405) and you’re treated to gesture control. Position your finger in range of the sensor and twirl it clockwise or anti-clockwise to move the volume up and down accordingly. From the outside it may look strange, but once you’re locked into the sensor’s sweet spot, it works surprisingly well. However, we stick to the old fashioned and most convenient method, the controls on the steering-wheel.
Also on the menu of features is DAB/FM/AM, a 20GB hard disk, Bluetooth, and Spotify built-in. You can access the Spotify app and any downloads from the service on your smartphone.
BMW also offers an Online Entertainment package with unlimited access to Deezer or Napster for £160 per year. This includes the ability to stream directly from the cloud or download it to the car’s hard drive. You can also use your chosen streaming service on up to three additional devices.
One of the neatest features offered by the BMW 5-Series is Apple CarPlay. Instead of plugging your iPhone into a USB socket to connect, the 5-Series offers the wonder of wireless. Your iPhone connects and communicates with Carplay via Bluetooth – when you leave and enter the car it connects and reconnects automatically and in practice it works pretty consistently.
There are a number of different sound modes to help tailor the system to your tastes. These include Studio, On Stage, Concert and Lounge. We’re big fans of the default Studio setting, which delivers the best balance of focus and immersion. Here you’re presented with the most solid and accurate soundstage, with instruments and vocals hanging in their own space.
‘Lounge’ is essentially a Studio setting optimised for rear passengers. There’s a definite shift of focus from the front of the BMW to the rear when it’s activated. Great if your 5-Series doubles as an Uber.
‘On stage’ is the setting we’d opt for if you want more immersion. Here there’s a greater sense of the music washing over you. Instruments and vocals are less front and centre – everything sounds less regimented and more expansive. It’s a more relaxing listen than the Studio setting.
‘Concert’ appears to lift the soundfield in an attempt to give the impression you’re in a larger venue than a 5-Series cabin. However, it sounds a little over-processed for our liking.
Settling for the Studio mode, we’re impressed by the openness and clarity of the sound. Highs are transparent and confidently defined. There’s plenty of bite to notes but they never draw blood. It’s an enthusiastic sound, but not overly aggressive. Vocals are communicated in an engaging and expressive manner, only becoming shouty when the music demands.
Play Linkin Park’s Numb and the system captures every ounce of power and emotion in the late Chester Bennington’s vocal. Switch to Something by The Beatles, and the anger dissipates, the system relaxes and delivers the slower more melodic musings of George Harrison with a great deal of skill.
We manage to compare the B&W set-up to the optional Harman Kardon speaker system for the 5-Series and it’s no contest. The B&W option is pricier (£3750 versus £895) but the difference is night and day. The Harman system is seriously lacking when it comes to detail and dynamics and the treble and midrange performance isn’t in the same league.
B&W’s offering isn’t completely faultless, though. When it comes to capturing the detail and definition in bass notes we expect a bit more. Those subwoofers seem to struggle keeping a leash on the deep, probing bassline of Massive Attack’s Angel that makes it one of our go-to test tracks.
This means the delivery of certain notes is more lumpy custard than smooth pouring cream. That tubby bass also has a knock-on effect on the system’s timing – it makes alt-J’s Breezeblocks sound out of sorts, and the complex rhythms don’t gel as seamlessly as they should.
B&W’s Diamond Surround Sound System has loads of ability and displays more than enough sonic skills to convince us to tick the options box. But, it still needs to polish out those imperfections in the bass to pick up that elusive fifth star.