Bowers & Wilkins Px7 S3 ANC Headphone Review: Bluetooth 5.2 Futurism in a Worthy Upgrade

Bowers & Wilkins PX7 S3 Introduction

Bowers & Wilkins has almost a full decade of experience building its particular style of slim, unobtrusive, and beautifully stylish headphone designs. Px7 S3 is no ordinary point version upgrade from the Px7 S2 & S2E; S3 brings tangible improvements to sound quality and customization from a combination of improved driver and software support. New to the Px7-line are the S3’s 5-band EQ and support for the aptX Lossless Bluetooth codec. These updates alone may be enough to entice Px7 S2-owners to upgrade. 

The ANC system also received performance tweaks to what had already been solid, if not quite best-in-class noise cancelling technology. There are the usual slight improvements to mic placements for clarity and a light tweak in aesthetic design and portability. Personally, I get less excited about mics and ANC, but it’s good to know that Bowers & Wilkins seeks incremental improvements in these areas. What comes as a surprise about Px7 S3 is that the British speaker company has some additional features in store for later this year via firmware upgrade. Some of these upcoming features will harness new capabilities of Bluetooth 5.2 including LE Audio and Auracast, which we’ll detail below. But the firmware update that really caught my interest is Bowers & Wilkins’ plan to deploy its own unique twist on spatial audio built on its core True Sound audio tuning standards. 

The updates are being finalized at Bowers & Wilkins’ R&D labs in Southwater and are said to launch later in 2025. Let’s take a closer look at what these new BT 5.2 developments may mean for users, and why B&W’s take on “spatial audio” might just be worth hearing. 

Southwater R&D Lab Upcoming Features 

Longstanding Bowers & Wilkins fans may be aware that many of its audio technology breakthroughs are developed at its own acoustic research facility, or “University of Sound”, originally created by John Bowers in 1981. The facility moved to the historic English town of Southwater in 2019 and is now officially known as Southwater Research & Engineering (SRE). Engineers at SRE have developed a unique audio processing technology that will bring a unique form of spatial audio to Px7 S3.

B&W Southwater Research & Engineering

Bowers & Wilkins Unique Take on Spatial Audio

Rather than a binaural rendering of Dolby Atmos or standard surround DSP, Bowers & Wilkins has elected to “stay in its lane” with audio processing focused specifically on 2-channel music sources. What they’re going for will be a natural extension of their reference tuning baseline that B&W calls “True Sound”, dedicated entirely to faithful music reproduction. It aims to heighten our perception of acoustic space by recreating the experience of listening to music over a pair of speakers in a room. That’s a sound Bowers & Wilkins researchers know well. Instead of chasing the theatrical immersive effect of an Atmos-mixed sci-fi movie, their True Sound processing promises a more grounded, natural headphone experience many of us recognize from everyday listening. 

I don’t normally get excited about spatial audio headphones. Too often, binaural surround effects are overwrought and end up distracting from the original stereo mix. I’m relieved that what’s in development at B&W’s Southwater Research & Engineering labs isn’t trying to reinvent how we listen to music. The natural experience of stereo speakers in a room with your head in the sweet spot is a deceptively simple, brilliant idea. Subtle room acoustics in an effect that simply nudges the soundstage forward without creating a swirl of sound could be exactly the kind of spatial audio I can get behind. 

Bluetooth LE Audio & Auracast Explained

Other features to be deployed to Px7 S3 in a future update are Bluetooth LE Audio and Auracast. These are relatively new capabilities to Bluetooth 5.2 and little is known about how they’ll be employed in Px7 S3, or if these technologies will become widely adopted outside of Bowers & Wilkins. 

Bluetooth Low Energy (LE) Audio 

No, “Low Energy” is not a Trumpian slight against a rival politician, this time “low energy” means greater efficiency, something battery-powered devices always need. Bluetooth LE has been around awhile for connections to devices that only use incidental bits of data, like email notifications popping up on your smartwatch. But it’s never streamed 2-CH audio until now. Bluetooth LE Audio is part of the Bluetooth version 5.2 spec that grants compatible Android V13+ devices the ability to transmit audio signals using an uber-efficient LC3 (Low Complexity Communications Codec). 

LC3 is another compressed Bluetooth audio codec that uses less power while transmitting less data while providing an even cleaner, more transparent audio signal to your headphones than SBC at its higher data-rate. LC3 isn’t meant to compete in audio quality with higher-end codecs like aptX HD/Adaptive or Lossless, but it might be a good choice when your device and headphones are low on power or you just don’t need the best possible wireless sound quality. 

Unfortunately, Apple iOS hasn’t fully implemented Bluetooth LE, LE Audio or LC3 yet. Apple’s iOS 17 has a Bluetooth LE feature specific to hearing aids, so the company could launch support for these functions anytime. Unfortunately, with no competition to Apple on iOS, it could be a long wait.

Multi-purpose and Energy Efficient—Bluetooth LE Audio

Auracast

Auracast is another interesting new technology made possible by Bluetooth V5.2 on compatible Android 13+ devices. In effect, your mobile device acts as an on-the-fly Bluetooth radio station that can be received by a (theoretically unlimited) number of Bluetooth LE Audio-compatible headphones, like (post-FW update) Px7 S3. Auracast will transmit using the new LC3 codec to any receiving headphones with LE Audio capability. 

Exact implementation isn’t yet known. But I envision using an Auracast browser, perhaps part of the B&W Music app, that enables you to transmit or discover local streams. If a time comes when LE Audio/Auracast technologies are widely adopted by a variety of manufacturers, browsing for Auracasts in public spaces could someday become relatively common. But it will likely be a mixed blessing. It could be a great feature at the gym where an Auracast browser might pick-up a flood of local LC3 broadcasts. But considering the musical tastes of the average Android-user/gym rat, you may just wish you had your old Sony Discman back.   

Style - look and feel 

The latest entry, Px7 S3 follows Bowers & Wilkins’ distinctively stylish, less-is-more design ethos with a pair of headphones that wear small on the head and don’t shout for attention. In classic Bowers & Wilkins style, the headphones let the finely embossed brand tag on each earcup do the attention-grabbing, those who know, will know. 

Since wireless headphones are almost always closed-back and built for portability, designers go to great lengths to ensure they’re on the lighter side of the weight spectrum. I never find myself fretting about headphone weight, especially in anything under 1-lb. But Bowers & Wilkins’ slim fit with durable plastic shells has no problem with sufficient lightness. Px7 S3 managed to shave 7-grams off the weight of Px7 S2E, making the new S3 weight-in at a featherweight 300-grams, that’s just over half a pound! You can order a pub burger that weighs more than the Px7 S3. They may not be the lightest wireless ANC headphones in their price range, but their breathable leatherette wrapped memory foam earpads and headband certainly make them among the most comfortable to wear, and that is an important metric for judgement. For increased portability, Bowers & Wilkins has designed Px7 S3 to lie flatter in its included storage case that’s now even narrower than its predecessors. Shaving a few millimeters off the case depth doesn’t seem like much, but it can make a difference for air travel when carry-on luggage space is at a premium.

B&W Px7 S3 exudes fine quality at every press of the tactile controls 

Bluetooth Codecs 

The default Bluetooth codecs, AAC (iOS) and SBC (Android) are present and accounted for. But for those of us who use an Android phone, why wouldn’t we want to enjoy the benefits of higher-bandwidth, higher resolution audio? For advanced Bluetooth codecs, Bowers & Wilkins has been loyal to Qualcomm’s aptX family. As expected for the Px-line, they offer the gamut of aptX codecs from Adaptive to HD, but now B&W has finally added the Qualcomm’s latest, aptX Lossless for the highest bandwidth available in commercial Bluetooth codecs at 1.2-mbps throughput. Unfortunately not many of us will get to hear how Qualcomm’s new “Lossless” codec sounds over Px7 S3, because Snapdragon Sound compatible devices are still relatively few. I normally avoid the term “future proof” in technology purchases, because it doesn’t really exist. But aptX Lossless is a “future-proof” measure worth having available if you’re not embedded with the iOS ecosystem. 

For now, Apple iOS devices only stream Bluetooth through the AAC codec. But for Android-users that demand top sound quality, be sure to check your phone’s Developer Options to ensure you’re getting an “HD” Bluetooth stream to use its full 24-bit Bluetooth audio capacity. Many Android phones leave enhanced Bluetooth features off by default to err on the side of consistent connection at the cost of throughput. It probably reduces technical support calls from people who don’t know what Android developer options are, but they’re probably not the sort to care about optimizing for sound quality.  

Optional USB/3.5-mm Listening

Px7 S3 facilitates hard wiring your playback device via USB using provided USB-C-to-USB-C cable for a phone. I’d suggest acquiring a longer USB 2.0 or higher USB-C-to-USB-C cable than the one provided with the Px7 S3. Or you can use a USB-A-to-USB-C to connect to a computer. 

The USB connection to the DAC allows you stream music at up to a theoretical 24-bit/96-kHz and it works fine using a wide selection of streaming music services on your phone, but that’s the best I can say about direct-DAC USB listening. The DAC chips and tuning of the headphones seem to be optimized for Bluetooth streams because I really didn’t hear any obvious gains in sound quality performance over hearing the same music wirelessly over Bluetooth aptX HD. This was surprising to hear after testing “DAC Mode” on Focal Bathys and Bathys MG which provides a performance gain that's difficult to ignore. But Bathys isn’t aptX Lossless compatible, Focal clearly intended DAC Mode to be the premium way to hear Bathys MG. Most people who buy a pair of wireless headphones probably aren't thinking about hard-wiring them with a USB cable.  

A USB-C-to-3.5-mm cable is also included in the case so you can use Px7 S3 with an analog audio out such as in-flight entertainment systems. But again, you may want to buy a longer cable for a bit more flexibility when using in-flight or any 3.5-mm output. 

Networking with Bowers & Wilkins 

In my USB-cable testing, I couldn’t get the Bowers & Wilkins Px7 S3 to work with USB Audio Player Pro (UAPP), an audiophile-grade Android music app that can take direct control of external USB DACs. Once connected, UAPP provides access to local network and streaming music libraries while bypassing Android’s Audio Hardware Abstraction Layer (HAL)—the system layer that typically resamples all USB audio to 48-kHz. This bypass allows UAPP to deliver bit-perfect playback at any file’s native sample rate and bit depth. Unfortunately, the app appears unable to access the Px7 S3’s DAC directly, possibly due to hardware or firmware limitations related to the new headphone’s integration with the Snapdragon Sound ecosystem. So, if you're using USB connection from an Android device, the headphones may be capable of streaming up to 24-bit/92-kHz, but chances are all USB streams are resampled to 48-kHz before exiting the USB port. In return for potential troubles with USB-cable streaming, Snapdragon Sound chips gives Px7 S3 the aptX Lossless codec, so I'd say it's a fair trade-off in pair of headphones that I can only conclude is optimized for Bluetooth music streaming rather than hard-wired. 

DLNA/UPnP

This leads to one minor gripe with the Bowers & Wilkins Music app. To stream a local network’s music library, whether via direct USB connection or Bluetooth, you’ll have to find a third party app since the B&W Music app won’t connect to DLNA/UPnP servers. Support for DLNA/UPnP seems like an omission if the Music app is intended to be the central control for a variety of Bowers & Wilkins household wi-fi/Bluetooth audio devices. There are plenty of options to workaround the limitation with any free UPnP app on the Play store, but I'd prefer working directly out of B&W's app for easy access to its 5-band EQ and other headphone controls while navigating my local music library.

Improved Px7 S3 Driver vs. Sx7 S2 & Px8 

I did some back-and-forth critical listening between the Px7 S2, Px8, and Px7 S3 with the Music app’s ‘True Sound’ engaged. This mode enables Bowers & Wilkins’ reference sound tuning for each headphone, removing any EQ customization. The sound from all three is impressive over aptX Adaptive’s 24-bit connection at 420 kbps. All deliver Bowers & Wilkins’ smooth, warm tone with a naturally open midrange, and each presents impressive detail — free of boom in the bass or shrillness in the highs. Each headphone in True Sound is equally at home with crunchy hard rock and booming electronic beats, without overemphasizing either. It’s a proper and mature tuning for these headphones, and that’s why the 5-band EQ adds a bit of fun to your listening. 

Px7 S3 (right) next to Px7 S2 & Px8: All beauties, but you just can't beat the gleam on Px8's diamond-cut brushed aluminum ear-cup housings  

Why not create a savable custom EQ preset specifically to bring out the bassy boom in Prodigy and a V-shaped setting to accentuate the leads for Rush? Any differences I’m hearing between the three headphones likely come down to the drivers and chipsets used inside. The Px7 S3 uses Bowers & Wilkins’ biocellulose driver diaphragm, the same material it’s used since the first Px-series over-ear headphones, until the Px8 introduced a more rigid carbon fiber driver. Biocellulose is a paper-like substance and despite many audiophiles’ knee-jerk reaction to paper cones in speakers, it’s not a bad thing. 

As a driver material you’ll find biocellulose in some of the best headphones on the market. Developed in the 1980s, it’s still especially popular with the Japanese manufacturers like Sony, Fostex and Denon. The slight difference in detail I hear between the Px7 S3 and S2 is likely due to Bowers & Wilkins' stated improvements to the rest of the driver. This would involve making the magnet and voice coil working behind the diaphragm just a little lighter and more sensitive. You can hear it in the finer details when comparing Px7-entries. However, the carbon fiber of the Px8 really stands out when dynamic range hits a peak across the frequency spectrum, especially at a higher volume. 

I found the strengths of Px8 especially noticeable at the crescendo of ‘Light of the Seven’ from the Game of Thrones Season 6 soundtrack, my go-to whenever I want to stress test a driver. Px8’s carbon fiber driver has the rigidity to hold the finer details together at all the right moments. 

Subjective Audio Listening 

Blur - ParkLife 1994: Tidal maintains several of the 90s Brit-pop band’s albums in pristine, uncompressed 24-bit/96-kHz “MAX” grade. I’m sure the band that declared “Modern Life is Rubbish” is hardly impressed. The album’s title track, Parklife is a humorous pop-rock singalong anthem of peak 90s English lad culture that today comes off as a nostalgic slice of the old country. It’s also the song that inspired a semi-political Russell Brand joke: Whenever Russell Brand completes a sentence, someone should always call out… “Parklife!”; a commentary on how the fallen comedic actor routinely mistakes his bombast for profundity. But for a borderline novelty song, Parklife features unexpected sonic depth. 

On the surface it’s a rollicking four-piece guitar and drum rock song that intermittently cuts to spoken-word witticisms about daily life at an English park over an ambient layer of sounds from a city park. On lesser headphones you’d hear an edgy rock song with sound effects, but Px7 S3 brings layered depth to the park’s sound-effects that cut-in and fade to the sometimes jolting back-up vocals that seem to interrupt at random intervals. I was impressed! 

Bowers & Wilkins makes the most of Bluetooth’s limited bandwidth with depth, detail and its own unique sound signature. While the soundstage isn’t particularly wide, Px7 S3 brings just a bit of extra detail and space to sonic images. This is evident in everything from the ambient park sounds to the jangly opening riff of Graham Coxon’s Telecaster. Every random sound, in a song that brings a lot of them, is deliberately placed. 

Parklife may not be a boundary-pushing work of art, but it has a soul that captures in equal measure the vibrance, innocence and danger of an English city park inside just three minutes. It’s a simple, honest feast for the ears that attempts nothing so profound as a Russell Brand sentence.  

Discovering Pink Floyd

I didn’t give Pink Floyd a chance until well into adulthood. It was music my dad listened to, and classmates in high school held them in such fanatical reverence that it gave me an aversion.

Yet, I always loved electronic music, especially the pioneers like Tangerine Dream, Fripp and Eno. In the days when rock was king, people would say that electronic music has no soul and I’ve always disagreed. While much of today’s pop music has congealed into a bland porridge of party-club beats that use electronic tech, it has little interest in experimentalism or creating sonic vistas the way the early pioneers of electronic sound once did. 

I was surprised to discover that Pink Floyd was one of those pioneers of electronic music. Starting with Dark Side of the Moon (1973), Roger Waters and Richard Wright employed classic synths like the EMS VCS3, Synthi, and Minimoog. The band continued electronic experimentalism through 1975’s Wish You Were Here and few bands did it like Pink Floyd. 

Pink Floyd - Welcome to the Machine: Tidal carries a hi-res 24-bit/192-kHz versions of Wish You Were Here and other Pink Floyd classics. This was the song that finally reeled me in. When Welcome to the Machine begins after “Shine On…”, you get a sense of travelling through a dark, unknowable space of layered sonic images, the throb of the VCS3 builds a menacing tone as processed vocals “welcome” the listener sound faraway, yet everywhere at once. At the 2-minute mark, the chorus brings relief in the organic tones of Gilmour’s acoustic guitar, breaking the tension of the VCS3’s rhythmic hum. 

The imaging effects that sounded impressive in Blur’s Parklife are pushed to new heights in Welcome to the Machine. Despite Bluetooth’s bandwidth limitations, the Px7 S3 delivers a solid rendition of the synth’s environmental effects. Soundstage is suitable, but I don’t really look for soundstage width in closed-back headphones and Px7 S3 makes up for the closed-back soundstage in imaging precision and detail. Hearing each string articulated in the strum of the acoustic guitar is a highlight, a lifeline of humanity in the midst of the machine. 

The beauty of hearing Welcome to the Machine over Px7 S3 is its deft imaging that carries you through this nightmarish soundscape. In this case it’s the devouring monster of Roger Waters youthful innocence prior to conjuring this song. Ironically, the electronics of the Minimoog and VSC3 play the role of the impersonal, soul draining machine, but to great effect.

David Gilmour and Richard Wright with the Legendary VCS3 

Conclusions 

Px7 S3 is a worthy update over Px7 S2 and 2E, with incremental improvements in the finer details in any track. But Px7 S3 may surprise listeners with its sense of space through clean sonic imaging and the same warm tonal character that has made the Px7-series a hit for Bowers & Wilkins. The entire presentation is gift wrapped in a stylish package that brings a lightweight comfort that I could listen to all day. 

But the release of Px7 S3 raises a question, which headphones are Bowers & Wilkins flagship? 

Technically it’s still Px8 with its advanced carbon fiber driver and its uncanny ability to ride-out any dynamic crescendo with delicate details at every frequency intact. But the Px8 misses out on the 5-band EQ, aptX Lossless and is not expected to receive any of Px7 S3’s future updates. Although, I anticipate a future Px8 S2 that brings Bowers & Wilkins stellar carbon fiber driver to a similar Px7 S3 Qualcomm Snapdragon Sound chipset. 

Px7 S3 - Daily User Champ!

Sitting at a desk tapping fingers on a laptop is my daily use for headphones, I usually select one of a few favorite passive headphones and plug it into my kit before getting to work. I’d be happy to use Px7 S3 on the days I must return to an office setting. 

Today’s wireless ANC headphones are designed for use-cases away from the desk or home where passive headphones can’t go. This is where Px7 S3 brings key incremental improvements in portability and noise cancelling. In the past I never cared about ANC and was always thankful to turn it off. Nowadays while walking around town, I find I appreciate ANC more than ever before. I appreciate the escape it affords from areas with sub-par ambient noise levels that may include some jackass listening to music on a phone speaker. Bowers & Wilkins ANC technology may not fully isolate you from the sounds of jackasses or screaming babies but it does a fair job at sonically pushing them away.

What really makes Px7 S3 a worthy upgrade if you already own Px7 S2 are the “firsts” for Bowers & Wilkins headphones. It's first to stream in aptX Lossless, compatible devices may not be plentiful yet, but it could be part of your next phone. They’re also the first Bowers & Wilkins headphones to let you deviate from its True Sound reference tuning with a full 5-band EQ. Technically, Pi8 earbuds were first to feature the 5-band EQ, but I maintain that earbuds aren’t proper headphones. 

As for some of the other upcoming firsts for Bowers & Wilkins headphones, I can’t say I’m exactly chomping at the bit to try out LE Audio, Auracast or the LC3 codec. But what Bowers & Wilkins has planned for spatial audio certainly has my attention. 

Px7 S3 lays a little flatter in a slightly narrower protective case than previous Px7 headphones

I don’t say this often about equipment I review, but at its retail price of $450 (USD), these are the portable wireless headphones I’d personally buy. They hit the cost/performance sweet spot for about the same retail price as Sony WH‑1000XM6. My primary purpose for headphones is always sound quality. You don’t buy Bowers & Wilkins headphones for best-in-class noise cancelling, even if these days B&W is getting close to Bose and Sony. But while Bowers & Wilkins may only be slightly behind more mainstream brands in noise cancelling, the mainstream brands have a long way to go to get close to Bowers & Wilkins in that warm openness in sound. Regardless of your musical taste, whether you listen to Pink Floyd or soulless electronic music, Px7 S3 are the rare wireless ANC headphones that will let you close your eyes and let its stunning imaging take you to any sonic vista. 

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.