Bowers & Wilkins Pi8 & Pi6 Wireless IEM Review & Comparison

Bowers & Wilkins has nearly 60 years in audio where it's built a reputation for excellence in loudspeakers. It’s one of the few speaker companies whose historic accomplishments in R&D still reverberate through the industry. In more recent years, the storied UK speaker company has embraced modern demands for portable wireless audio technology. From its earliest P5 wireless headphones to the latest in its Pi-series of true wireless IEMs, Bowers & Wilkins says that its guiding light remains sound quality that elevates recorded music, even if that means through Bluetooth and a cell phone.

The Pi6 and Pi8 are both completely new earbud designs intended to upgrade its previous model, Pi7S2 true wireless earbuds. The design team’s research into earbud ergonomics has paid off in uniquely shaped earbuds that are deceptively balanced and fit securely in my ears, even during workouts. Their premium look and feel stay true to the company’s approach in aesthetic design: the high-gloss outer touch surfaces bearing the Bowers & Wilkins signature mark lend a vague resemblance to cufflinks, providing a touch of class to the wearable tech in your ears. Their IP54 rating makes them resistant to occasional splashes of water and dust, so they should hold up during your sweatiest gym session.

Under the Hood: Bigger Drivers, Better Tech 

The design team that overhauled Bowers & Wilkins wireless headphone lineup, resulting in the Px8 wireless headphones in 2022, was tasked with bringing its experience and innovations to a new line of wireless earbuds. The team created a miniature earbud version of the carbon cone driver, the same composition found in popular Bowers & Wilkins loudspeakers and the 40-mm driver that made the Px8 its flagship wireless headphones. The result is the new 12-mm carbon cone earbud driver designed to make the Pi8 its new reference-quality wireless IEMs. They also designed a new 12-mm bio-cellulose driver for the Pi6, the same highly sensitive driver material used in its Px7S2 wireless headphones and the Pi7S2 earbuds the Pi6 replaces in its lineup. At 12-mm the new full-range drivers are small, but for earbuds sealed directly to your ear-canals they’re huge! Larger than the Pi7S2’s 9.5-mm 2-way driver config and double the size of Sony’s 6-mm drivers in the WF-1000XM4, the Pi8 and Pi6 are sure to pack a serious punch.

Beyond the revamped aesthetics and drivers, the Pi8 and Pi6 also feature updated microtechnology by Qualcomm. The Snapdragon Sound chips bring Bluetooth 5.4 and aptX Adaptive at 24-bit, 96-kHz. Exclusive to Pi8 is Qualcomm’s new aptX Lossless codec, capable of a 1.2-Mbps stream at 16-bit/44.1-kHz and approaches CD-level bit-rates over Bluetooth. The new aptX Lossless codec provides a higher Bits-per-second than even Sony's LDAC that peaks at 990-kbps. Unfortunately, you’ll need one of the relatively small, but growing number of Android Snapdragon Sound phones to unlock the Pi8’s aptX Lossless potential.

Pi8 Case Retransmission: Cure for iOS AAC?

A unique feature of the Pi8 is case retransmission, which lets you stream hi-res Bluetooth from non-Bluetooth sources. Connect the case via its USB-C port to a USB or 3.5-mm digital or analog audio source, and it will transmit sound directly to the earbuds in aptX Adaptive 24/96. This could come in handy for non-Bluetooth portable audio devices and airline entertainment systems with a 3.5-mm headphone jack, or any computing device that lacks Bluetooth but has a USB port. It’s a potential game-changer for long suffering Apple iOS users who have long been limited to the AAC Bluetooth codec. Pi8's case retransmission feature offers a potential workaround for higher-quality Bluetooth audio from iOS.

Touch Controls 

Both the Pi6 and Pi8 basic touch controls are intuitive and easy to use, but perhaps a bit too simple. One tap to pause/play or answer incoming calls, double-tap to skip a track, and triple-tap to reverse a track. The Bowers & Wilkins Music app provides minimal flexibility in programmable touch controls. Only the earbuds 3-second hold-touch offers a secondary function. By default, the hold-touch will increase/decrease volume on the left & right earbud, respectively. The app lets you switch the left hold-touch to toggle between ANC and transparency modes. I'm a strong proponent of any headphones offering users a one-touch method of entering acoustic transparency mode for safety reasons. When listening to music while walking in the streets it's important to maintain situational awareness. My minor gripe with the hold-touch ANC toggle is that it skips ANC “off”. I prefer it off and am happy that Bowers & Wilkins includes it, even if only through the Music app, not all ANC headphones let you turn ANC or transparency mode completely off. I prefer my noise cancellation passive, the old fashioned way! The right hold-touch on the other hand, can be set to trigger your phone’s voice assistant. I know I'm breaking my own rule about situational awareness, but I like to keep the 3-second hold-touch on the default volume up/down control.

Active Noise Cancelling... or Not 

The Pi8’s noise cancellation is powered by the same advanced algorithm found in the Px8 headphones, excelling at reducing high and upper-midrange chatter you'd hear at busy coffee shops these days. It’s strong enough to make extremely noisy environments like my lawn mower seem just a little bit more distant, allowing me to easily listen to a podcast while mowing. The Pi6, while lacking the same premium ANC, still performs well. Any improvements over the Pi7S2's ANC are only due to Pi6's all-new mic placements. The Bowers & Wilkins Music app lets you switch between ANC mode, transparency mode and fortunately, includes the ability to turn both off for pure listening.

Siblings in Sound! Pi8 & Px8: Same carbon cone driver composition, similar-sounding default tuning.

Music App & EQ 

The in-app EQ is somewhat disappointing. The Pi6 only provides minimal bass/treble controls with a +/- range of 6-dB. Unfortunately, that’s the same limited EQ users get with the Px8 headphones, which is underwhelming for its flagship headphones. You’ll need a third-party app for more sophisticated EQ adjustments.

The Pi8 unlocks a solid 5-band EQ with the same +/- 6-dB in the Music app. It’s a significant upgrade for the Music app, which will hopefully become standard for future Bowers & Wilkins wireless products. Once you set levels on the 5-band EQ, one tap lets you activate “True Sound,” to bypass EQ altogether and restore the default tuning. It would have been nice if the Music app allowed a programmable touch control to toggle True Sound on/off so I can easily make direct sound-quality comparisons as I tinker with the EQ on Pi8. Even more annoyingly absent from the Music App are any savable EQ presets or built-in EQ profiles from Bowers & Wilkins. The Music app is not exactly a tinker's delight.

Pi6 Bass/Treble Control vs. Pi8 5-Band EQ

Bowers&Wilkins Pi6 vs Pi8 Sound Quality 

Despite my gripes with the EQ, the default tuning is excellent! The first thing I noticed while switching between Bowers & Wilkins' two new wireless IEMs is that their overall tuning is almost identical. In fact, I had to really listen to tell them apart by sound alone. I’d describe their default tuning as neutral and sophisticated. It provides appropriate attention to their lush mid-range rather than burying it in steep elevations of the highs and lows. Both the Pi8 & Pi6 earbuds come out-of-the-box with a refined sonic profile that sound's custom-made for nearly any genre of music. From the breathy tones of a classic jazz vocalist like Ella Fitzgerald to Metallica’s aggressive riffs to the dynamic subtleties of J.S. Bach or Daft Punk, moving across music genres seems effortless for the Pi6 and Pi8. 

Loudness War Listening Tests: Pi6 vs. Pi8 

For listening tests, I chose two familiar albums with opposing recording philosophies and a range of musical styles. Metallica’s Death Magnetic is a notorious example of the peak loudness war when it was released on CD in 2008. Still, it’s a great metal album that represented a stylistic return to the band’s raw roots. But its loudness level was so high that many complained of clipping and distortion from its original release. On the other side of the spectrum is Daft Punk’s Random Access Memories, which earned studio mixer Mick Guzauski five Grammy Awards, including Best Engineered Album. Guzauski says he purposely recorded the album with lower compression and volume to give it greater dynamic range. 

Metallica Death Magnetic 

For years, fans have called for a remaster of Metallica's Rick Rubin-produced Death Magnetic. So far, only Apple has obliged with an exclusive version on Apple Music and iTunes called an Apple Digital Master. I’ll be listening to Tidal’s 24-bit/96-kHz FLAC transfer rather than a remaster. But, if Tidal stored Death Magnetic to high-resolution digital  FLAC files, I assume it will have also normalized loudness levels to solve the problems of original recording. 

That Was Just Your Life: The album opener begins with the low-volume thrum of a heartbeat in the background before a guitar sets a steady, ominous melody. I’m already impressed with the openness of both pairs of Bowers & Wilkins’ new earbuds that present sufficient dynamic range in Metallica's typical slow and low opening. The song builds with dual bass drums picking up the tempo for Hetfield to enter a riff that cuts with the energy of a 2-stroke chainsaw.

Both pairs of earbuds are similar in their presentation of frenetic metal. In fact, they sound more like high-quality closed-back headphones than wireless earbuds. I hear clear separation and imaging, distinct edges between instruments through periods of peak energy and volume. I don't believe I'd hear that much detail if Tidal's FLAC file was still cursed with over-loudness. Switching back and forth between the Pi6 and Pi8 at various sections of this track, I’m reminded of the Px8 and Px7S2 headphones in both sound profile and differences between the two models. The differences between the Pi8 and Pi6 are subtle, but the Pi8 brings just a little bit more—of just about everything. The Pi8 presents slightly better sonic imaging and just a bit more space, even if it's just the space inside my head. I’m quite impressed that the Pi6 is so close in sound quality.

Daft Punk Random Access Memories

The French duo is known for its futuristic aesthetic and electronic dance music that embraces technology. But despite productions that include vocoders and a synthesizer, this Daft Punk production uses only 100% real analog instruments. Even the band's synthesizer is a 1970s-vintage analog Fender Rhodes piano. The album runs the gamut of musical styles, from slow and easy lounge to funk and disco at hyper 100 beats-per-minute dance tracks. Bowers & Wilkins' new earbuds made it easy to listen through the changes in musical styles without feeling a need to adjust the EQ or switch to different headphones.

Lose Yourself to Dance: One of the signature hits on the album was created in collaboration with Pharrell Williams. While listening on both new earbud models I lost myself in toe-tapping instead because I’m not a dancer. A unique feature I listen for on this track is the heft in the four-on-the-floor beat played on the kick drum by studio session pro John “JR” Robinson. I believe it's the four-count beat that uniquely hits with a heft that carries its own gravitational pull while entering sub-bass territory. But at 100-BPM, that extra heft must peak and decay quickly. Lesser headphones may either fail to deliver the beat’s full weight or muddy it. But I’m pleased to report that both the Pi6 and Pi8 threads the needle with panache, presenting the beat with excellent speed and clarity. 

Touch: This slow track is a kaleidoscope of sounds and shifting musical styles, but it opens using paleo-synths that sound like a Boards of Canada track. The song brings periods of minimal instrumentation accompanied by the distinctive voice of classic crooner and Muppet Show veteran, Paul Williams. This song has it all, with Williams’ voice alternately accompanied by a grand piano, the Fender Rhodes and traditional disco electric guitar complete with a wah pedal. I was especially impressed that both the Pi8 and Pi6 presented spaciousness in the echo from the grand piano as each key reverberates and decays into what sounds like an auditorium. Spaciousness from earbuds is a tricky phenomenon to describe. It’s not quite what I’d call “soundstage” when the sound is piped directly into my ear canal. But they deliver a sense of openness inside my head. The advantages of the Pi8 are apparent, but again only slightly.

Daft Punk Thomas Bangalter on the Fender Rhodes collaborating with The Stroke's Julian Casablancas

Conclusion: Hi-Fi Sound & Wireless Convenience 

When a new round of high-end wireless headphones came out in 2022, between Focal Bathys and Bowers & Wilkins Px8, wireless ANC headphones reached a new plateau and I could no longer deny that hi-fi sound quality had truly come to wireless headphones. Now in 2024, Bowers & Wilkins has just proven to me that wireless earbuds can also deliver legitimate hi-fi sound. With advances in Bluetooth bit-rates I knew it was in the mail, but am surprised how soon it has arrived. Whether you choose the Pi6 or Pi8, you’re getting premium build quality, modern earbud esthetic style, spacious sound and refined tuning that rivals a good pair of closed-back hi-fi headphones. While the Pi8 offers slightly better overall sound quality for those who demand the finest, it also brings more features—aptX Lossless, five-band EQ, and case retransmission. But the Pi6 is a stellar option for those seeking similar high-end sound at almost half the price. My only problem with the sound quality of the Pi8 and Pi6 wireless IEMs is they may have brought us one step closer to the day that my collection of wired headphones, DACs and headphone amps become obsolete.

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