Bowers&Wilkins Px8 S2 Review: True Immersion & Lossless 24/96 Sound!

Bowers&Wilkins Px8 S2 Introduction

If you’ve followed Bowers & Wilkins’s iterative upgrades and headphone naming convention over the years, once we saw Px7 S3 just months before its new flagship was announced, we knew a Px8 S2 was on the way. Bowers & Wilkins latest generation headphones brings in-app software updates and design tweaks both esthetically and a whole new digital audio signal chain that makes Px8 S2 without a doubt the finest headphones Bowers & Wilkins has ever produced. Qualcomm’s aptX Lossless codec, 5-band EQ and new Bluetooth 5.3 capabilities are all available within the brushed aluminum housings of the Px8 series and ready to be heard through its incredibly resolving carbon cone drivers. 

Like the Px7 S3, some additional software features made possible by the 5.3 Bluetooth spec are still pending firmware update for Px8 S2 including; LE Audio and Auracast. But one of the promised updates has recently been launched, B&W’s unique take on spatial audio that it calls True Immersion.

But the first time you remove the slip-cover, open the box and remove a brand new Px8 S2 from its included carrying case, what hits you after the aroma of fresh electronics and luxury-grade leather is the look and feel of a true Bowers & Wilkins flagship headphone.

Px8 S2 Looks Stunning in its case, revealing exposed cable and polished ring around outer brushed aluminum earcups.

Px8 S2 Style and Fit 

Px8 S2 carries the signature Bowers & Wilkins headphone design in its slim, subdued profile with elegant esthetics. When Px8 launched in 2022 it was in my opinion the most esthetically beautiful headphones I’d ever seen and Px8 S2 subtly raises the bar. Like its predecessor, Px8 S2 is a presentation of fine metalwork. Polished aluminum arms reach from a Nappa leather headband to its brushed aluminum and leather earcups that can rotate to lie flat in its case. Everything seems to fit together with the precision of a Swiss watch. A mirror-polished ring around the edge of each earcup adds the allure of quality and a metallic presentation that the plastic housings on the Px7 series simply cannot match.  

A new accent that visually differentiates Px8 S2 is a short length of braided cable exposed through aluminum housings above each earcup. The exposed cable is a design nod to Bowers & Wilkins’ headphone history. The British speaker company’s first headphones, the P5 way back in 2010 featured loose cables to the earcup. Bringing back exposed but secured cable lends Px8 S2 a modern industrial vibe.

Like its Px8 predecessor, the parts of Px8 S2 that touch your head are cushioned high quality Nappa leather as opposed to the leatherette of the Px7-series. To maintain the superior cooling properties of real leather it’s worthwhile to give them some basic care and light cleaning once in a while to maintain that luxury feel. But on the aforementioned downside, Bowers & Wilkins’ may have passed the point of diminishing returns in its quest to make Px8 S2 ever lighter and smaller than its predecessor.

Smaller Isn't Always Better

The new S2’s have slightly lighter, narrower earcups than Px8 (2022). The design choice allows the sides of the headband to sit smaller and even closer to your head while the headphones shed about 10-grams of weight. Px8 S2 weighs in at 310-grams, down from the 320-grams of the original Px8. But the nominal weight loss comes at a cost. While I appreciate B&W’s signature slim-fitting headphone designs, I preferred the slightly thicker, even if slightly heavier Px8 earpads. The thicker, removable and user-replaceable Px8 pads have been replaced by Px8 S2’s thinner earpads that relieve less tension on the arms of glasses. Worse yet, the easy snap-on earpads of the original Px8 are now more complicated to replace for S2. Bowers recommends having the earpads replaced by a professional. 

Those of us with bigger heads (and ears) may notice the inner earcups brush up against the tips of our ears. For me it’s a small quibble, I’m not usually aware of it. But it’s my humble opinion that headphones weighing-in at anything less than 400-grams (about .8-lbs) are already light and in no need of trimming. Despite my gripes, Px8 S2 are still among the most comfortable headphones I’ve ever worn, but they surely don’t need to be any slimmer.

Wireless ANC Headphone Features

Bowers & Wilkins wireless ANC headphones may include all the modern convenience technologies expected in its product category, but they’re built around a sound-quality-first ethos. Even if that sound quality-first philosophy may involve trade-offs in other features. Bowers & Wilkins headphones provide improved if not industry leading Active Noise Cancelling. But activating ANC gives me no perceptible change in tonality and little to no loss in detail in any frequency band, even when listening to music in a quiet room. I appreciate that B&W has always included the option of turning ANC off completely in the app, which is my preferred choice in a noise-free environment. Turning on ANC in a busy environment like when working on a laptop in a coffee shop, they suitably push ambient noise away to help me focus. On one hand, Bowers’ ANC might not be up to Sony or Bose levels, but on the other hand, they’re not Sony or Bose headphones.

Px8 S2 provides serviceable call and voice quality in busy environments thanks to microphones tweaks that have significantly improved call quality over Bowers & Wilkins’ generations of ANC headphones. The iterative improvements in these features are part of a longstanding partnership with Analog Devices (ADI). The company specializes in high-performance analog & mixed-signal ICs that have helped Bowers & Wilkins remain competitive with clear 2-way, noise rejecting voice communications without compromising sound quality.   

The S2 battery life remains at the same 30 hours of playback as the original Px8, a suitable, if not industry-leading, listening time from a single charge. Personally, I can’t imagine needing more battery life beyond the 20-hour mark. In fact, our own Gene DellaSala took a pair of Px8 S2s to Japan during his recent Denon/Marantz visit and reported that they delivered great-sounding tunes and effective noise isolation for his entire 20+ hours of air travel, with battery life to spare.

But if you’re looking for a marathon listening session that promises to drain the battery, you can treat yourself to USB-C connected audio mode, which can charge the Px8 S2 while you listen to music. You could run the Px8 S2 indefinitely by alternating between Bluetooth and a hard-wired connection while charging. Which leads me to one of the Px8 S2’s most important yet underrated upgrades: a true USB-audio mode thanks to Bowers & Wilkins’ next-gen audio-signal architecture.

The App is where you check your battery life, set EQ and various lifestyle controls that I tend to leave off.

Px8 S2: Not Just Another Bluetooth Headphone

One quibble I had with the original Px8 was its mediocre performance when USB-connected to a digital audio source. But why, you may ask, would anyone want to tether wireless headphones to a device? 

In theory, directly connecting lossless or hi-res digital audio stream to a wireless headphone’s USB port, depending on its design, could bypass Bluetooth compression and other related processing steps. A direct digital audio signal path should plug your stream directly into the headphone’s DAC, DSP and amps so you can really hear what those carbon drivers are made of. 

The original Px8 re-produces its usual impressive sound quality through its USB-C port without Bluetooth compression using an included cable. But in practice USB-connected listening provided little in tangible sound quality gains, not what you'd expect when bypassing Bluetooth compression. While experimenting with lossless FLAC files I found that any bit-depth/frequency streamed into Px8’s USB port was transcoded to 24-bit/48-kHz, the same rates as Bluetooth. It seemed Px8’s integrated design leans heavily on its Qualcomm QCC5127 Bluetooth SoC. But that's all changed in Px8 S2!

New Bespoke Digital Audio Chain

Bowers & Wilkins next-gen architecture gives Px8 S2 a new, more linear signal path with only purpose-built processing steps all the way to the headphone's drivers. Perhaps in anticipation of lossless digital audio sources, the drivers themselves have been tweaked with lighter, more sensitive chassis, voice coils and magnets than original Px8 while keeping Bowers & Wilkins signature angled drivers designed to enhance imaging.

The new architecture employs the updated Qualcomm QCC3084 SoC for Bluetooth 5.3 support all the way up to aptX Lossless. But the Qualcomm SoC's involvement in the audio signal chain ends at decoding a wireless stream. After Bluetooth is decoded or bypassed entirely via a USB audio connection, it's all Bowers & Wilkins custom technology created in cooperation with ADI. 

Like the Px7 S3, Px8 S2 employs discrete DSP, DAC and Amps, the new linear signal path lends on-paper benefits to your Bluetooth sound, but when you USB-connect your headphones with high-quality, lossless recordings you’re in for a significant leap in sound quality. 

Px8 S2 Powered Headphone Platform 

Directly connecting Px8 S2 via USB-C to a digital audio source unlocks a level of performance that losslessly decodes up to 24-bit/96-kHz, free of Bluetooth compression or extra transcoding. The new architecture puts Px8 S2 squarely into Focal Bathys territory with a legitimate competitor to Bathys’ DAC Mode. This means the Px8 S2 can play a dual role in any hi-fi headphone enthusiast’s collection. Px8 S2 already stands among the best sounding wireless headphones on the market for portable use. But when you’re ready to listen to lossless or hi-res audio through a USB cable, it gives a serious pair of passive headphones plugged into a separate DAC/Amp a run for its money. And you get this dual-role inside one convenient carrying case.

Easily Overcome Android's USB-Stream Quirk

Using a smartphone as a digital source is a convenient way to use USB-connected mode. An Apple iOS device with a USB-C output already allows a bit-perfect stream with no fuss. Unfortunately, that’s not so for Android. Android may get all the good Bluetooth codecs that iOS doesn't, but Android is known to run interference with your USB-output through its annoying USB Audio Framework that may downscale or alter your audio signal. This is why Android users CANNOT simply load up a lossless or hi-res music app and start streaming songs through USB expecting the same bitrates you see on your music app's display. 

The solution is any number of Android apps that bypass Android’s USB output controller to take direct control of your headphone’s DAC. Personally, I like USB Audio Player Pro (UAPP) to solve Android's quirk. UAPP is a flexible music app that grants access to local network music storage through DLNA/UPnP and a variety of music streaming services, including Tidal for lossless or hi-res streaming. 

Bowers & Wilkins told us:  

In Px7 S3 and Px8 S2, we use both a dedicated DSP AND a separate, dedicated ADI headphone amplifier. This combination of dedicated DSP and dedicated amp is used in addition to the main Qualcomm chip used in each product. 

True Immersion Update: Worth the Wait?

Bowers & Wilkins music app is where you'll find the new 5-band EQ and other lifestyle controls for Px8 S2, and if your received the latest firmware update, you'll see "True Immersion", Bowers & Wilkins new proprietary take on spatial audio. Bowers’ processing for an immersive two-channel audio experience is not like Dolby Atmos or other object-based 3D audio format that requires specially encoded tracks. I normally don't care about "surround" effects on headphones but I was interested in this feature when it was announced due to the company’s unique goals with its processing. Rather than a garish 3D-sound aimed at recapturing a multi-channel home theater experience, Bowers’ wanted to simulate the subtle acoustic reflections when listening to a pair of Bowers & Wilkins speakers in a room.

The experience Bowers & Wilkins was going for with True Immersion.

I gave it a chance with a variety of music styles and tracks, but the results for me were not impressive. I found that when True Immersion is engaged, vocals immediately sound compressed and far away. It’s as if the lead singer is in another room but never smashes through the wall like Steve Tyler in the Walk This Way video. But I stuck with it, attempting to find the musical style or track that brings out the best in True Immersion. Acoustic music seemed to reveal the effect while mitigating its downsides. If you can get past the drop in volume and what sounds like a veil of compression and allow your ears to adjust, there are times where instruments seem to have a slightly wider soundstage. In mellower music with less instrumentation, I did notice reflections in the upper midrange, it may sound like a note on a guitar reflecting off the back of the room for some ambient depth. Unfortunately the spatial effects are few and accompanied by a neutering of Px8 S2’s impact and detailed dynamic punch. I hate to say it, but for me the best part of listening to True Immersion is sliding the controler back to the “off” position mid-song and hearing the Px8 S2 spring back to life with its full range, impact and power. 

My expectations are low for any effects added to headphones because headphones already provide immersive sound, and Px8 S2 doesn’t need the extra processing. Many closed-back headphones do suffer from extreme in-head localization, which isn't a problem for Px8 S2. Given these headphones’ excellent imaging and detail, all it takes is a good quality recording to capture the ambient room acoustics of any performance.

The distinct slim style of Bowers & Wilkins headphones: Px8 S2 & Px7 S3

Bowers & Wilkins Px8 S2 Sound Quality

I did a lot of back-and-forth comparison between Bluetooth aptX HD (the highest my Android device allows) and connected USB-Audio. Px8 S2 can make me forget I’m listening to Bluetooth, usually when out on walk while listening. While USB connected, the overall character and tonality remains the same as what you’ll hear over Bluetooth. Whether Bluetooth or USB, you'll hear its "True Sound" signature warmth with the added clarity of Px8 S2's highly resolving carbon cone drivers that brings the warm sound to the border of analytical with a sub-bass that packs a punch. 

But USB-audio brings out more headroom, resolution and energy. The lower noise floor and greater dynamic range means aggressive music hits harder while softer music brings cleaner lifelike micro-details with more open space and greater definition to sonic images. 

Bowers & Wilkins has long employed the aptX suite of codecs by Qualcomm that deliver greater bitrates over Bluetooth. Although Px8 S2 is capable of aptX Lossless, this requires one of a relatively small number of devices featuring full support for Qualcomm’s Snapdragon Sound. Without aptX Lossless, your Bluetooth pinch hitter is aptX HD, or if you have an Apple iOS device, chances are you're using Apple's AAC. 

Px8 S2 MAX Bitrates: Bluetooth & USB-Audio 

• aptX Lossless: 1,200 kbps at 16-bit/44.1-kHz
• aptX HD: 576 kbps at 24-bit/48 kHz
• AAC: 256 kbps at 16-bit/44.1-kHz  
• USB-Audio: 4,608 kbps at 24-bit/96-kHz 

USB bitrates are a major jump over Bluetooth, but you’ll rarely, if ever hear it at 24/96 maximum. When I first started testing Px8 S2 in USB-mode vs. Bluetooth on my Android device, I knew this was a job for some lossless metal.  

Iron Maiden The Number of the Beast: The first song I tested via USB was Iron Maiden, The Number of the Beast right after hearing it via Bluetooth aptX HD. After watching 28 Years Later: The Bone Temple, I cannot separate this song from Ralph Fiennes fiery live performance of this song.  Using the included USB-C-to-USB-C cable, I connect my Android phone to the headphones, then push the headphones power switch only to the halfway point, one click without activating Bluetooth slider. Loading USB Audio Player Pro immediately detects the headphone’s DAC and requests permission to take control. Permission granted! I accessed a 24/96 FLAC copy of the album stored on my UPnP network for some critical listening. 

The intro narration is a spooky calm followed by the guitar’s mounting tension, just after the 1-minute mark, Bruce Dickinson's scream releases the tension as the band drops the legendary rapid-fire riff that anticipated the next decade of metal. The riff hits the drivers in a showy display of dynamic range. Compared to Bluetooth, the direct connection brings more detail across the spectrum. You’ll hear a tidy separation between Smith and Murray’s guitars alongside the booming drums and bass in the low end, even as the sonic cacophony blends in harmonious rage. The sense of controlled detail seemed to draw my fingertip to the right earcup to raise the volume just a little bit more. 

Metal specializes in loud sonic chaos, so to test Px8 S2 over USB I wanted to try something more measured with a touch of ambience.

Streaming at bit-rates (kbps) far exceeding aptX Lossless

The Band: The Night They Drove Old Dixie Down: For organic instrumentation, you just can’t beat The Band’s modern-traditional folk ballad in The Night They Drove Old Dixie Down. It’s not everyday you hear a melodica and a slide trumpet, thanks to Garth Hudson, immortalized in music. The modern pop structure hidden beneath layers of folk instrumentation makes this song sound like it’s from another time, a time that shouldn’t exist but did. It was the 1960s. My local 24/192 FLAC collection is downsampled to 24/96 to fit the capabilities of Px8 S2’s DAC. No sweat, I’m not a hi-res purist and I likely won't hear any difference between hi-res and 16/44.1, but I’ll take hi-res for any good quality recording or remaster.  

The old folk-rock song highlights Px8 S2’s stunning imaging with each instrument given its own clear space and directionality. It brings an organic quality to the old upright piano that actually sounds like a small piano with the ambience of being played in a small room, perhaps an old saloon. The strings in Hudson’s lonesome melodica are brought to life over top of Helm’s back beat, every instrument has its place within clear sonic borders and range. Then as Helm’s narrative of Virgil Caine enters the chorus, the spatial tidiness is shattered as the rest of the band’s backup vocals and instruments swell across a generous sound-stage for a pair of closed-back headphones. 

The detail and space sounds impressive, even when listening to the song over Bluetooth. Px8 S2's deft reproduction of this song with only 576-kbps at its disposal made the effect of hearing it for the first time with a USB-connection almost jarring. I had only heard hints of Px8 S2’s acoustic 3-dimensional space over Bluetooth, the USB connection placed me somewhere in the back of an old saloon listening to The Band. USB-audio provided the finer details to the song’s 30-second ending crescendo when all instruments and vocals join in at once while still letting you place every sound’s location at the front of the room, no True Immersion necessary here!

Nine Inch Nail - Tron Ares: The Onyx Black Px8 S2’s industrial vibe brings to mind the music of Nine Inch Nails and NIN recently released the soundtrack to a Tron movie I’ve never seen. This is an excellent album loaded with musical homages to electronic music pioneers. It includes riffs from early NIN, the previous Tron movie soundtracks by Daft Punk and electronic pioneer Wendy Carlos’ work on the original Tron and the Clockwork Orange soundtracks. All these little nods to other songs are weaved into various tracks waiting to be discovered. 

AptX HD vs USB-to-DAC Audio Comparison 

Infiltrator: Bluetooth aptX HD: From the start of the track, the crackle through the dance beat may have you checking for bad wiring. Please, do not adjust your set! Throughout this album you’ll hear glitches, feedback and electrical fuzz that I must admit caused me some concern on my first playthrough.

The purely instrumental piece does a lot in just under three minutes. Centered on a dancefloor beat that crackles with an electrical texture when a groovy rhythm joins with a menacing scale while a sardonic melody can be heard in the upper-midrange, the effect of holding all these sounds together create a sonic conflict. I don’t know what sort of movie scene this piece is meant for, perhaps it conveys innocence and hidden danger. The layered elements make this a deceptively complex composition that finishes inside 3-minutes. 

Infiltrator is a well-crafted piece with sounds across the frequency spectrum and the Px8 S2 handles it all with speed and smooth dynamic range that makes it pop and punch without exaggerated boominess. Setting the EQ to its True Sound default treats this track to deft speed and precision, although this album may benefit from EQing some added bass to really hear the driver's sub-bass capability.  

Infiltrator USB-to-DAC Test: This was a stark example of USB-audio mode blowing my mind. Over Bluetooth aptX HD I heard the electrical fuzz-effect over the dancefloor beat as merely adding a textured layer. But the USB-connection’s depth and detail along with a repeated listen revealed the fuzz-effect carries a counter-melody throughout the track. It’s a small but explicit detail that perhaps trained musical ears would hear right away. But for me, it took the enhanced sense of space and depth of the USB-audio to bring out that extra detail that was easily missed. 

But if you like what you’ve heard on the Tron Ares soundtrack, search for the new Tron Ares Divergence album. Exactly as the album title suggests, Reznor and Ross get more creative and explore more soundscapes in each track without the burden of carrying a movie score.

Conclusion 

Bowers & Wilkins has described past flagship releases as “the best headphones we’ve ever made”. But Px8 S2 stands at a pinnacle for the brand that now has over 10-years of experience making headphones. It’s going to be a tough act to follow with a Px8 S3.

Built on the solid foundation of the original Px8’s aluminum frame with real leather comfort and a lean, lightweight fit, they won’t scream for attention when you’re wearing them. Like all Bowers & Wilkins headphones, they provide a low-profile with touch of class. The sonic clarity and dynamics of its carbon cone driver deliver a wireless sound quality that pushes the limitations of Bluetooth compression. Px8 S2 adds BT 5.3 with aptX Lossless to push Bluetooth limitations even further, along with a 5-band EQ to customize your sound. Bowers & Wilkins new flagship takes its place among the best sounding wireless headphones of this generation. Improvements to the electronics inside the earcups that contribute to great sound over Bluetooth also allow you to unleash their full capability using USB-audio mode for a true audiophile headphone experience at a lossless/hi-res 24-bit/96-kHz. This is why I think of Px8 S2 as a Powered Headphone Platform rather than just another wireless ANC headphone. It affords you listening options that make it two hi-fi headphones in one.

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