Few things are inextricably linked to each other, like the open road and music. Or, let’s be more realistic and say traffic snarls and Google Maps. In fact, with rising congestion across the globe, in-car entertainment systems have gained a level of sophistication never seen before in the OEM space. So while we still strive to find that perfect ribbon of tarmac behind the wheel of the perfect car, it’s also important to address the everyday victories. The “stuck-in-traffic-but-headbanging-to-AC/DC” sort of victories. Speaking of AC/DC, EVs incidentally make for the perfect testing bed for sound quality of stock audio systems; thanks to the inherently quieter cabins, the vanishingly low NVH levels and their relatively newer system architecture compared to ICE counterparts. So we gathered up a quartet for this test, with our focus solely on sound quality and sonic characteristics of each car in question, without delving into their respective infotainment systems or operation.
Our quartet of Avengers included the Audi Q8 e-tron, Mercedes-Benz EQE SUV, Jaguar i-Pace and BMW iX, all roughly in a similar price bracket but vastly different in their cabin design and system configuration, and each bringing to their cabin a different and premium branded audio system.
The task was simple then; to ascertain which car could separate the Weeknd from the Milli Vanilli based on stringent parameters such as Soundstage, Clarity and Precision, Tonality, Bass Definition, Maximum SPL (sound pressure levels) and Structural Rigidity. While these systems would be heard out on the open road, we tested them with the car parked in Autocar’s very own studio, in controlled conditions that allowed us to maintain extremely low ambient noise levels. This allowed us to pinpoint misgivings more easily than when driving around, which would lead to body flex on our battered city roads. We’d also avoid the incessant honking in the perpetually trafficated Mumbai roads that might corrupt our impressions and findings.
Soundstage
A fundamental difference between most cars and a live performance or home audio system is that we listen to the sound coming primarily from the front. Not from the sides or the rear like in a lot of lesser car audio systems. While all cars in this test are equipped with a front centre speaker, some pull off the illusion of placing the vocalist right in front of your eyes a lot better than others.
Barring the Jaguar i-Pace, every other car here offers some level of surround sound control that affects how much direct sound you’re listening to as opposed to reflected or diffused sound. Surprisingly, the i-Pace cleverly manages to circumvent this software limitation by physically placing its tweeters as deep into the A-pillars as possible, increasing the sense of depth. The Q8 e-tron, despite help from B&O wizards, doesn’t conjure the same effect; the sound never going beyond the boundaries of the cabin. The EQE SUV and iX, on the other hand, can make the cabin sound much larger than their cubic volume would suggest, increasing the immersive effect of a 360-degree sonic bubble while maintaining a strong front and centre image. The EQE SUV ever so slightly edges out the BMW iX with its accuracy and pinpoint imaging as well. If you’re adventurous enough, the EQE SUV also offers Dolby Atmos capability via MBUX and its Apple Music integration. The BMW, on the other hand, offers sounds and chimes designed by none other than Oscar-winning composer Hans Zimmer, and while it doesn’t have any bearing on the overall soundstage per se, it does have an interesting Harman Kardon sample clip built into the BMW OS if you want to show off the sonic fireworks to your friends.
Bass Definition
More often than not the word “boomy” is used to describe a positive bass effect, but in reality, it’s the opposite of what is desirable. Low frequencies are usually the hardest to reproduce accurately in any car due to a variety of factors, including the size of the woofer, the enclosure in which it’s mounted, body panels being excited by bass energy etc. The list is long but our objective was clear – to crown a definitive winner when it comes to bass.
Surprisingly, both the BMW iX and the Jaguar i-Pace showed signs of resonance and energy-robbing vibration through the door panels. Nothing that can’t be fixed by taming the bass levels a bit, but for the sake of equality, all tests were conducted on flat EQ settings. Moving on to the Audi Q8 e-tron and the bass displayed a lot more authority and presence with a more liberal window to play around with the bass levels, depending on personal preference. But the Mercedes EQE SUV with its Front Bass concept bolts the subwoofer to the chassis itself and makes a real impression. The bass is taut, well-defined and never out of sync with the rest of the frequency spectrum, making for an engaging listening experience that sounds more cohesive than any other car in this group.
Clarity
Probably the most important aspect of judging the sound quality of any hi-fi system, home or car, is its ability to resolve detail and microdynamics. Ideally, without turning it up to eleven. It’s easier said than done but the contenders here are all equipped with branded audio systems that have many years of experience building high-quality home systems.
Hence, the critical speaker placement and shaping of the crossover has been achieved almost flawlessly on all these cars. With the amount of speakers present in any of these cars, it is imperative that the timing and phase of all speakers are correctly maintained to ensure maximum resolution from modern recordings. The BMW iX and the Mercedes EQE SUV have a slight edge due to their higher speaker count. The BMW also boasts of active drive units in the rear headrests and it aids in adding just the right amount of “fill”, without overpowering your ears with localised sound. If you like to tweak the sound to your preference both the Audi and the Jaguar do a fine job in maintaining intelligibility, whether it’s for speech on podcasts or vocals and music.
Tonal Balance
Having multiple speakers scattered throughout the cabin has its obvious benefits in terms of output and immersiveness, but it can also rear an ugly head in terms of imbalance. Almost every car made these days has tools for tone control (bass, treble, balance), but we are in search of the best blend without altering any settings.
Unsurprisingly though, our notes can attest that every car in this round-up performed at par, without undue emphasis on one frequency band over another. Using ‘Wish You Were Here’ by Seguridad Social made for a great test to judge whether the treble was out of pace with the mid-bass, but none of the cars showed any anomaly and made for an enjoyable experience overall. Again, the Mercedes EQE SUV does provide granular personalisation of the sound on every level, be it tonal balance, surround levels, sonic signature and sub-bass oomph so you can extract maximum performance out of it. But having said that, the Jaguar, Audi and BMW were hot on their heels when it comes to maintaining timing and rhythm, despite having at least a dozen speakers each!
Structural Rigidity
Everyone has experienced that at some point, when we are excited by our favourite electronic music track, the body panels of the car seem to share that excitement and want to play along. The chink in every stock audio system is the amount and quality of the damping material in the door panels and for obvious reasons, auto manufacturers want to reduce cost and weight, and skimp on this big time.
Within the realm of OEM systems, this simple test allowed us to crank up the volume of a bass 40Hz frequency test tone and audibly confirm rattling, squeaking and resonances. Now, these being luxury cars, they all proved that their build quality was exemplary, and the BMW iX, Mercedes EQE SUV and Audi Q8 e-tron all tied with an equal score. Even the Jaguar i-Pace was just a point down, indicating that overall, these are extremely well-put-together automobiles. One could always achieve a higher degree of performance by strategically adding acoustic treatment to areas of the door cards and subwoofer enclosure if possible, but all these cars proved that the inherently high structural rigidity of premium segment vehicles pays dividends in multiple areas beyond safety and dynamics.
Max SPL
Setting our SPL meter to ‘C’ weighting and response to ‘Slow’, we set out to unravel the loudest stock premium car audio system in this group. This should be down to the power ratings of their respective amplifiers, but like with all things audio, it’s rarely an individual function. Multiple factors like THD (Total Harmonic Distortion), driver excursion (how much the speaker cone moves during loud signals) and protective limiting circuits come into play to determine how loud a particular system will play. We cranked up the volume to the point where audible distortion set in and stopped just shy of that breaking point.
No surprises here, Mercedes beat the pack with the EQE SUV’s mammoth 710 watts of power on tap. It recorded a seriously loud and clean 105.4dB on the SPL meter, edging out the Audi Q8 e-tron by 0.4dB! The Audi too comes with almost the same amount of power at 705 watts, so they are matched point for point. The BMW iX’s 655 watts of power gave it the third loudest place in this test at a 101dB and yet again, it correlates with its power of 655-watts. The last, at 400 watts, is the Jaguar i-Pace that still manages a respectable 100dB, just shy of the iX even with a 200-watt power deficit. Talk about a photo finish!
Verdict
Finally, every car here performed exceptionally well across the board and the contest was closer than our expectations. And while sound is a hugely subjective discipline, we do have a winner, the Mercedes-Benz EQE. And this is also bearing in mind the multitude of parameters beyond the purview of this test like wireless Apple CarPlay/Android Auto convenience, placement of USB ports and wireless charging pad, implementation of phone mirroring on the infotainment display, ease of use, possibility of OTA updates and last but not least, user-adjustable controls. The EQE SUV offers the most comprehensive controls to ensure you get just the kind of sound you like from your car audio system. Its plethora of options is a nerd’s dream come true and its overall sonic presentation is dream-like too. The sound simply floats in front of you, without ever giving away the location of its 15 speakers and engulfs you in a sphere that makes any commute or journey a truly memorable one.
