KEF Reference Audio for Lotus Eletre S Review

Meet the so-called 'Reference' hi-fi for Lotus's spicy Eletre S. The company offers three audio options – good, better and best – with this KEF installation being the finest. The brief from management was apparently to make this "best in class" for those customers who can afford to pay a cool £104,500 for the car.

We're in a new world now. Long gone are the days of aftermarket 'DIN standard' car stereos, especially for exotics such as this. Some motorheads do still indulge in expensive custom installations, but these generally use the vehicle's own integral head unit as the source. Instead, cars are marketed based on the level of technology, entertainment, and information they are sold with. Lately, a big slice of that has been bragging about which hi-fi company your car maker has got into bed with, to provide the tunes. What was once a list stretching from Alpine to Zapco has now become a procession of premium hi-fi brands.

Lotus's corporate personality stretches back many decades and is unarguably cool – think Emma Peel's Elan S2 (above) in The Avengers and James Bond's S1 and S3 Esprits (below), the former handily also functioning as a submarine. The Hethel-based company also turned a dad car called the Vauxhall Carlton into a 176mph supercar-beating monster – search 'Lotus 40RA' for the tale of the sedan that the cops couldn't catch. So partnering with the right hi-fi brand was essential for this company, and KEF was duly approached. How so? Because it has also built great things over the years, from its leading-edge Reference Series 105 loudspeakers in the 1970s to the hugely popular LS50 now. 

For this partnership to work, KEF needed to know what it had to beat. So, its engineers spent a lot of time at Porsche and Bentley dealers, among others, and mock-ups of car cabins were duly created.

KEF's Dr Jack Oclee-Brown

To Lotus's credit, it showed great faith in KEF's approach, which involves top-end digital signal processing, bespoke speaker drive units, and copious amounts of power. Quite rightly, the two key aims were headroom and dynamics, rather than just sheer loudness. KEF played demonstrations to Lotus, whose team said, "Ah, we get it!"

Along with specifying the company's proprietary coaxial Uni-Q mid/tweeter array, KEF also had the opportunity to argue about the optimal locations of individual drive units for superior stereo imaging, and even to steal precious cabin space for enhanced bass. And that's why modern OEM car sound systems can work so well at this level. Not so long ago, the idea that the sound designer could argue about speaker positioning, let alone drive unit size, would have seemed ridiculous.

Up Close

So what was the result of all this planning? The Eletre sports a 4-inch coaxial Uni-Q driver array taken from KEF's LS60. It has been subtly re-engineered for automotive applications, ruggedised for use in rain-soaked car doors and/or extreme temperatures.

Each side's is positioned forward and high up, and gets 25W per tweeter with a separate channel of 45W for the coaxial cone behind it. The tweeters reach up from 3.2kHz, and the mids extend from 300Hz to 3.2kHz.

There's also a Uni-Q array in the middle of the dash as well as a pair for each row of seats. The Uni-Q's mid drivers drop down to just 2 ohm impedance, so the partnering amplification was carefully specified to deliver this low load.

There are four 55mm effects speakers, each receiving 25W, located high in the A-pillars in the front and in the headlining to the rear. These are surround speakers used for Dolby Atmos and other DSP applications, playing from 200Hz upwards.

Low frequencies are courtesy of 8-inch drive units in the front doors and 6.5-inch in the rears; they're said to handle from 70Hz up to 300Hz. Each of these gets 170W RMS. Their grilles are exquisite design features, with their holes echoing the shape of the Lotus logo. There's even a pair of rear (D-pillar) 100mm midband speakers, each with 45W RMS to drive them.

This alone would have been sufficient for lesser systems, but there's more! To start with, Lotus gave up vital handbag storage space for the force-cancelling dual-driver Uni-Core woofer. This is a game-changer, bringing absolute grip to the bottom end.

Its drivers get 270W RMS each, and can play down to either 40Hz or 60Hz, and up to 150Hz or 200Hz with variable overlap depending upon the mode. Lastly, the so-called 'Fresh Air' subwoofer actually ports to the outside of the car. It's from an Australian licensor and is used by other top-end OEMs, such as Bowers & Wilkins, in their Volvos. It has 250W RMS feeding each of its two voice coils, and has a claimed frequency response of 20Hz to 60Hz.

All of which adds up to a reality-bending 2,160 watts of power via 23 speakers with 24 amp channels. This is similar in power levels to high-end aftermarket systems, but has the critical locational and constructional advantages of having been designed before the car was built. So Eletre pilots should at all times be careful with that volume up/down control on the steering wheel.

As with all modern cars, the master controls for the sound are via the car's screen. Needless to say, you can connect your smartphone via Bluetooth, and the system operates Android Auto and Apple CarPlay wirelessly. You can also plug a flash drive in via the USB-C port.

The Listening

Simply put, I was blown away! The KEF Reference system makes the Lotus Eletre one of the best-sounding cars I've ever sat in. It is fabulously detailed from the lowest bass notes to the highest treble whispers, and everything is framed within an incredibly vivid stereo soundstage. All that clever DSP number crunching makes the music appear as if it is beyond the confines of the car – a trick that few rivals properly pull off. Bass is fantastic, blending seamlessly with the rest of the sound whilst having an apparent endless reserve of power. You get the same 'velvet hammer' sensation as from KEF's domestic hi-fi and home cinema subs.

The system started up in 'Driver' mode, with my listening initially done in the front driver's seat. In truth, this is the person who will benefit the most from it, as many car journeys are made solo. Via the DAB radio, the sound wasn't particularly special – but that's thanks to the embarrassingly low bitrate that stations like Absolute Radio tend to stream in. The KEF system is unapologetically revealing and requires a reliable source. To this end, I cued up Yello's Tied Up from my smartphone and sat back. Dynamics were superb, the long crescendo in the opening section of the song coming across in a highly dramatic way. Tonally, the high end sparkled yet never screeched, the midband had a glassy clarity, and the bass was firm, thick and visceral.

Firing up the beginning of Disney's Snow White reboot, and everything sounded fabulously coherent, whilst at the same time rich and dripping with detail. My car didn't have Tidal installed, but playing music via Spotify, I was wowed by the excellent headroom and vast reserves of power – just like a serious home hi-fi system. Attack transients were super-fast, allowing the music to move along at great pace. All this was backed up by fabulous bass, which was aided and abetted by that deep-breathing subwoofer in the back.

The good news is that the driver doesn't get to have all the fun. This system also features 'All' and 'Rear' modes, and trying these while moving around the cabin of the car demonstrated the clever way the system has been designed for all passengers. Switching to 'Spatial' mode took the soundstage super-wide but reduced the impact, I found. Likewise, the 'Stage' setting puts the image even further in front of the listeners, but I question whether this was necessary, as the imaging is remarkable anyway.

The Verdict

With this model-specific installation, KEF has cracked car sound in a game-changing way. The Eletre S's system is an amazing way to enjoy music, making it just as memorable as any other aspect of this super-SUV. From its wide bandwidth and seemingly endless reserves of power to point-source image placement and forensic levels of detail, this is an incredible setup. Overall then, KEF's Reference option is quite a revelation, and one more reason – as if you needed it – to invest in this new Lotus.

[Thanks to Lotus Cars Ltd. and H.R. Owen (Hatfield) for their assistance with this feature.]

For more information visit KEF