Not only is BMW’s 7 Series saloon up there with the very best in terms of luxury and comfort, it also offers one of the most tech-packed interiors you’ll find on four wheels.

And that includes the sound system. For BMW’s flagship full-size saloon, you wouldn’t expect Bowers & Wilkins to be too far away. After all, the legendary British speaker brand offers sound systems for several models in BMW’s portfolio, including the five-star set-up we tested in its superb iX electric vehicle.

For the new 7 Series, B&W has pushed the boat out even further with a Diamond Surround Sound System which uses no fewer than 36 (yes, 36!) speakers. And now we’ve been fully immersed we can report back with our findings…

Price

BMW’s premium executive saloon doesn’t come cheap – our press car as tested costs £142,354 including all options.

The Bowers & Wilkins Diamond Surround Sound System is part of BMW’s Ultimate Pack, available for the 7 Series. It isn’t available as a single option, which means you have to pay a pretty hefty £22,000 for the privilege, although the pack does cover a whole suite of tech options 

It includes everything from massage and ventilated seats to BMW’s Sky Lounge panoramic sunroof and high-tech Parking Assistant Pro which helps you slot the sizeable saloon into any space that can accommodate it.

Systems

In a first for Bowers & Wilkins, there isn’t just one sound system on offer for the 7 Series; there are two different options available to potential buyers. There’s the standard set-up which comes equipped to any car that rolls off the production line and there’s the optional step-up system.

So, the standard Bowers & Wilkins Surround Sound System uses 18 speakers powered by an 11-channel amplifier and has a total power output of 655 watts.

Impressively, the step-up Diamond Surround Sound System boosts the speaker count to 36, increases the number of powered channels to 32 and trebles the power output to 1965 watts.

25mm Nautilus® Diamond dome tweeters are added to the doors and dashboard, while an upgraded die-cast aluminium chassis is introduced to the car’s midrange/woofer speakers. An extra 10cm Continuum midrange driver is added to the dashboard (the system already features the cones in the front and rear doors). The Diamond Surround Sound System also gets 4 aluminium 3D speakers inserted in the headlining and extra headrest speakers in the front (they come as standard in the rear).

You also get more sound options to play with in the flagship system, including a 4D Audio Bass Experience which you experience through eight, ‘4D’ shakers positioned in the backrests of the front and rear seats.

Sound features and settings

Bowers & Wilkins gives you a choice of 4 different sound profiles to help tweak the sound to suit your sonic taste.

Studio claims to be the most authentic setting and during testing, we found this to be the case and helped deliver the most balanced and neutral audio.

The Concert setting adds space and extra processing. Music has more of a reverb around it to give the impression you’re listening in a concert hall. The soundfield lacks a bit of focus and solidity, instead preferring to give you more of a spread across the cabin.

The ‘On stage’ setting makes it sound like you’re yes, you guessed it, on stage surrounded by the band or orchestra. Again, you’re treated to a wide soundfield but there’s a greater sense of solidity and immersion thanks to a more prominent overhead effect. 

‘Rear’ simply caters more for passengers in the rear of the car, shifting information from the front of the cabin and into the rear speakers.

You can alter the ‘3D intensity’ in the concert, on stage and rear modes – this translates into more (or less) information being fed through the height speakers in the car’s headlining. During testing we preferred to keep the intensity relatively low so as not to to distract too much from the sound coming through the main speakers.

The 4D bass experience provided by those shakers can be set on a sliding scale of intensity from one to five or you can turn it off completely. It will be down to personal preference whether you like the sensation and if you do, how much you want to feel its impact.

With the feature turned on, we felt it combined a general rumble with more targeted punching sensations depending on the bass information in the track. We found it too intrusive and distracting on the higher settings and preferred the subtlety of the lower settings just to help add a little extra reinforcement.

You can even adjust the ‘Personalised Surround Intensity’, i.e. the audio coming through the headrest speakers for the driver and all passengers. Again, you’ve got a sliding scale of one to five or you can have it off. We found it can add a little boost to the feeling of immersion you get, but again, we wouldn’t have it on the higher settings as they cand distract from the overall sound.

Sound quality

Navigate the on-screen menus and you can fire up Bowers & Wilkins’ own ‘Experience the Sound’ audio demo, which gives you a quick blast of the system’s capabilities in a FLAC 5.1 surround sound mix.

It paints a good picture of the system as it throws effects between channels but we’ve got a few of our own hand-picked test tracks ready to roll.

We start with Candy Paint from Post Malone and you are immediately drawn to the level of detail on display. The slightly echoey chimes that start the track and hang around at the top of the sound field sound pristine and sharply drawn.

They sit in their own space and are joined by Malone’s vocal which hangs nicely in front of you. It sounds textured, emotional and believable. Then there’s the repetitive patter of a drum machine that taps away in the background but blends effortlessly into the soundstage.

Low frequencies make their presence felt – they’re weighty and solid although we’d like a bit more control and definition. The system doesn’t seem able to sharpen those edges and discriminate between notes quite as effectively as it can with the mids and highs. The track also lacks a bit of dynamic thrust and flair which some systems use to help grab and hold your attention.

Switching to Beethoven’s Symphony No.5 in C Major under the control of Herbert Von Karajan and once again the system’s ability to strip out fine detail in the mids and upper realm comes to the fore. The string section sounds wonderfully precise from start to finish and how the system handles high frequencies is a real treat.

The space around the orchestra allows for clear differentiation between the different sections. Quieter moments are allowed space to breathe, aided by the BMW’s well-isolated cabin which keeps listeners nicely isolated from tyre and engine noise.

Verdict

There’s no doubt the Diamon Surround Sound System is an impressive set-up. To get all 36 speakers working together as a cohesive unit can’t have been a simple task and it does produce an immersive and insightful sound. There’s a huge amount of detail on offer and the sense of refinement and sophistication, especially at the top end is something that few rivals we’ve heard can match.

We’d like the set-up to sound a bit more fun and for the low frequencies to be tightened a touch but for long journeys travelling in luxury this system has a lot going for it.

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