Bowers & Wilkins PI3 Review

July 9, 2021, noon

The PI3 is an around-the-neck in-ear Bluetooth headphones from Bowers & Wilkins -- maker of high end audio equipment since the 1960s.

The Bowers & Wilkins PI3 are high performance in-ear headphones designed to deliver the highest quality mobile personal audio experience combined with the convenience of wireless operation in a compact easy to wear design.

And they in fact deliver. Of the other headphones I currently use -- an Audio Technica ATH-m50xBT, a Sony WF-1000XM3, a Sony WH-1000XM4 -- or any I have used in the past these seem to be the best, with the possible exception of the Audio Technica ATH-DSR5BT or ATH-m50xBT. They provide accurate and balanced sound reproduction without overemphasis in any region of the spectrum. They also have a rare feature among wireless headphones in that they can be used in either wired (with USB-C) or Bluetooth mode while charging through the USB-C cable. We discuss these and other features of the Bowers & Wilkins PI3 in this article.

Introduction

I bought the Bowers & Wilkins PI3 headphones when I was becoming increasingly dissatisfied with the battery life of my then-everyday use headphones, the Sony WF-1000XM3 true wireless headphones, and saw these on sale at Costco for $99.99, an excellent value at half of the MSRP of $199.99.

These headphones are the lowest end of B&W's line of in-ear Bluetooth headphones, which consists of the PI3, another around-neck in-ear headphones, the PI4, and two true wireless headphones. The true wireless headphones can't really be compared to the PI3 and PI4, but among these two there are signigicant differences in the fundamental audio electronics which make it difficult to rank them.

PI3 PI4 PI5 PI7
Hybrid Dynamic-Balanced Armature Yes No No (Error in manual?) Yes
Driver Size 9.2mm 14mm 9.2 mm 9.2 mm
Microphone 1 (telephony with Clear Voice Communication v1) 2 (ANC), 2 (telephony with Clear Voice Communication v1) 4 total, configuration not specified 6 total, configuration not specified
aptX Yes (Adaptive, HD, Classic) Yes (Adaptive, HD, Classic) Yes (Modes not specified) Yes (Adaptive, HD, Low Latency, Classic)
Adaptive (Active) Noise Cancelling No Yes Yes Yes
True Wireless No No Yes Yes
Battery Life 8 hours 10 hours (with ANC on) 4 hours (case 20 hours) 4 hours
Charging 15 min. for 2 hour life 15 min. for 3 hour life 15 min. for 2 hour life 15 min. for 2 hour life
Magnetic Clip Sensor No Yes N/A N/A
Wear Sensing N/A N/A Yes Yes

The PI3 Packaging
Click on any of the thumbnails to view a slideshow of the images.

Whatever their placement in the lineup of B&W's in-ear Bluetooth headphones, they deliver on the marketing claims of delivering the "highest quality mobile personal audio experience". This is perhaps thanks to the

exclusive custom designed Hybrid Dynamic-Balanced Armature drive units, paired with two separate dedicated amplifiers producing a wide, accurate soundstage

Although the PI4 has more electronic features, the hybrid drive unit is unique to the PI3, which I would suspect allows the PI3 to produce more accurate and balanced sound accross the spectrum, while the PI4 would be better at producing stronger bass at the expense of more accurate reproduction at the higher end of the audio spectrum.

Technology Highlights

Bluetooth

The PI3 incorporates a Bluetooth 5.0 capable radio, as do most other Bluetooth headphones released in the past two years. Bluetooth 5.0 allows for 2X the data transfer rate, 4X the range, and 8X the packet size compared to Bluetooth 4.2, although there is a trade-off between data transfer rate and range at any instant. (Bluetooth 5.1, and even Bluetooth 5.2, standards exists but do not seem to have been implemented in actual products).

aptX and Other Bluetooth Codecs

The PI3 supports the aptX Bluetooth streaming codec in addition to the universally available AAC, as well as the lower quality, fallback SBC codec. The aptX support comes in three varieties: what B&W calls aptX-Classic, aptX-HD a variant released in 2018 that enables High Resolution Audio (96kHz, 24bit sampling), and the latest, aptX-Adaptive, which in addition to providing HD audio, provides dynamic low latency and an adaptive bit rate.

Wired Connection

The PI3 is rare among Bluetooth headphones in that it can be used while it is charging. This charging use is in one of two modes, the normal mode where a Bluetooth connection mode can still be made and maintained, and a wired mode through a USB-C connection that doesn't use Bluetooth. I was able to use this wired mode with my Razer Phone 2 without any problems. On two different Linux distributions however, this did not work, although the connected headphones were visible in audio settings (see below).

This is a standout feature that more headphones of this type should support. It essentially solves the battery life problem by making the headphones usable during charging.

Sound Engine

The excellent sound reproduction of the Bowers and Wilkins PI3 is due to the custom designed hybrid system which consists of a 9.2 mm dynamic driver and a balanced armature in each earphone. The details of each of these types of electronic acoustical devices is complicated but, generally, the dynamic drivers are best for producing powerfull bass due to their relatively larger size and increased range of motion which allows them to move more air, while the balanced armature is much better at vibrating at higher frequencies making it more adept at accurate reproduction of sounds at higher frequencies.

Companion App

A companion app is available via download from the Google Play and the Apple App Store. The app allows users to manage pairing and even set preferences on reconnection priority. It also allows users to specify the period of inactivity before the headphones power off. As a unique feature, the app can generate background soundscapes simulating, among others, rainfall, ocean waves, and a waterfall. As we will see in a future review of the Bowers & Wilkins PX7, the app offers more functionality with more capable headphones.

The Bowers & Wilkins App
The app is useful for managing multiple connections and can provide soundscapes. Functionality varies with the capability of available headphones.
Click on any of the thumbnails to view a slideshow of the images.

Missing Tech

Other technological features that users may want but are not included in the PI3 include NFC for pairing, active noise cancellation, and wear sensors for pausing and resuming of music when earbuds are removed and inserted. The NFC is a somewhat gimmicky feature that doesn't really add anything of value to the simple pairing experience. Noise cancellation is available along with other features on the more expensive PI4 including automatic pausing of music when the magnetic earbuds are attached to eachother.

What these and the other higher end in-ear headphones from B&W add in terms of technological features make up for these missing features, namely that they are usable while being charged either through Bluetooth or in a wired mode through the USB-C cable connection that is providing the charging.

Design

The headphones are essentially a thick flat wire with a soft silicone insulation with two hard plastic regions that house electronics. The electronic enclosures separate a thicker part of the wire that is behind the neck from two thinner sections that hang to the sides when not worn. The earbuds are at the ends of the thinner section of the wire. The most notable feature is the actual earbud and the rubber tips. Two tips are provided for each earbud in various sizes. One tip is the spherical part that fits in the ears and the other is a "wingtip" that can be optionally used to secure the earbud in the ears. The spherical bud features a foam filter inside the hole, presumably to keep the inner screen clean. This small detail is a nice addition not usually found in similar earbuds, and is completely effective in preventing the oily residue that builds up on the screen of the port on the earbuds. An example of the attention to detail is the spar in the rubber hemisphere's hole on the outer end that secures the foam inside the hole.

The Bowers & Wilkins Bluetooth In-Ear Around-the-Neck Headphones
The design features a soft silicone outer sheath except in the two electronics enclosures which are hard plastic.

Unfortunately the tips are the most problematic element of the design and the experience of using these headphones. After the first month of use they have become prone to becoming unseated from the port, for example as a result of interaction from a seat belt when not being used and the earphones are hanging loosely. Immagine frantically looking for these small hard to replace parts in all the crevices of a car.

The other in-ear headphones I currently use have the same problem. But when the tip separates from the earphone housing, the bud stays in my ear, due to the larger diameter of the largest tip provided by Sony, the rigidity of the tip, and the unique pockmarked texture of the tip surface that I imagine act like dozens of individual suction cups on the ear surface.

Controls

The PI3s have two sets of controls, one on the left node functions as a power and Bluetooth controls, a 3 second long press toggling power and a 5 second long press initiating Bluetooth pairing mode. The other set, on the right enclosure, comprises a main playback control button, and two buttons for volume control. All of the controls are easy to find by their placement on the enclosures and texture. The power/Bluetooth control is easily found on the bottom narrow edge of the enclosure. The single larger and knurled playback control button and two smaller volume control buttons, one on either side of the power button, are also easily found on wide side of the right enclosure.

The PI3 Controls
The PI3 Playback and Volume Controls Are on the Right Housing and the Power/Bluetooth Control is on the Left Housing

Apart from the easily unseated eartips, the single button control for multiple functions is the most undesirable part of the experience of using these headphones. A single press of the playback control button toggles between play and pause, two presses advances to the next track, and three presses reverses to the beginning of the current track. Timing a double presses such that the headphones recognize the user's intent is difficult, a triple press is even more difficult. Skipping to the beginning of the previous track actually requires two series of three perfectly timed presses. Dedicated forward and reverse buttons which could double as seek forward and seek reverse controls with a long press would provide a much better experience. Unfortunately, since the LG Tone Infinim (HBS-900), which had the ideal set of controls, it seems that the trend in-ear headphones has been to incorporate more functions in fewer buttons.

Feedback

Feedback is provided by tones, voice announcements and, an indicator light. Two distinct tones -- actually chimes -- indicate a change in power state. I was amused by how each chime was appropriate for each power state, with the power on indication exhibiting a lively and upbeat quality and the power off indication having the opposite character.

The voice announcements are pleasant and natural and provide feedback when the headphones enter pairing mode, connect to a previously paired source, connect to a second device, and disconnect from devices, explicitly indicating if the disconnection is from a second device. The voice prompt also provides a low battery warning at around 20% battery and when it powers off when the battery has been depleted. An interesting feature of the voice prompt is the British accent, one I've never heard in such a device, but appropriate as B&W is a British company.

Additinal feedback is provided by a single multicolor LED which is able to illuminates with a flashing or steady pattern, the combination of color and illumination pattern indicating different operating states. Although not documented, it seems that when the headphones are charging from a more powerful electricity source, the light flashes more quickly.

The PI3 Status Indicator LED
The PI3 has one LED that illuminates in various colors and patterns to convey different operation states.

The most welcome feature in terms of feedback is the precision of the battery level provided to the source device. On my Razer Phone 2 with Android 9, which supports Bluetooth 5.0, the battery level of the PI3 is displayed in 1% increments. I don't think I've seen this type of precision with any other headphone I currently use with the Razer.

Durability/Build Quality

The build quality of the PI3 is excellent. The control buttons are perfectly centered in their openings with no gap between the buttons and the housings. There is a barely perceptible difference in hight when running a fingertip accross the interface between the silicone and the hard plastic of the housing. And unequal difference between opposite sides of the housing and the corresponding feature in the opposite housing. But this is a nitpick with whcih B&W should be faulted as the overall build quality is excellent and considering the materials are also excellent.

Despite the overall build quality and the premium materials, in certain respects, durability may not be a strength of the PI3. I returned two pairs of these headphones because in both pairs the left headphone stopped producing bass frequencies within a week of purchase. I suspect the failure was caused by the Low Frequency Range Test at audiocheck.net which produces a sweeping tone starting from as low as 10Hz. After exchanging the second pair with a third about two months ago, I haven't repeated the low frequency test, and the current pair has not experienced the same, or any other, failure.

One other aspect of the durability of the PI3 is its ability to withstand moisture and dust.

The failure of the driver in two different units and the lack of water- and dust-proofing would seem to indicate a fragility and lack of durability. The fragility of the audio electronics, however, does not seem to be indicative of a fragility in the power electronics when exposed to high temperatures. I had been leaving the short USB-A to USB-C charging cable in an old spare laptop in between charges. This apparently caused a problem in the cable which caused it to overheat; I ignored this warning sign and charged with this cable anyway. When I returned to the charging headphones a few minutes after plugging it in, I discovered that the area of the enclosure around the USB-C port, as well as the plastic around the cable's connector, was warped due to the heat. But here, the headphones proved to be less fragile, as the charging electronics, controls, and status indicator LED continued to work as normal.

I wrote the above regarding the durability of the PI3 yesterday. Today, incidentally, when I first put on the headphones and started listening to my current Spotify playlist, I was surprised to find bass frequencies were not reproduced in, at first either earbud and later in only the left earbud. After some minutes of frustration during which I power cycled the headphones, disabled and enabled Bluetooth, browsed comparable headphones online, they inexplicably started working as normal. The only possible I can formulate is that at the time I began using them they had to be plugged in through the USB-C cable to charge because the batteries were completely depleted, the headphones having powered off during the previous use. So maybe there wasn't enough power at the time to power the bass driver and after several minutes of charging the charge level had reached a point where the bass driver could operate normally.

Comfort and Fit

The PI3 are for the most part comfortable. They are lightweight so the user may not even be aware of their presence. The only areas where I have felt any discomfort may be when wearing a collared shirt and the neckband gets caught in the collar when turning my head. This sometimes causes the stabilizer fins to shift so that some users may want to adjust them frequently. In my case the earbuds themselves are secure enough in my ears that I rarely am aware that the stabilizer fins have shifted.

Performance

Sound Quality

Whatever its flaws or areas in which it lacks, the sound quality of the Bowers & Wilkins PI3 is excellent. It produces a rich and full sound with a superior level of detail without an emphasis in any particular part of the audio spectrum.

As far as bass is concerned, it is able to produce a strong bass, but it is only apparent in some songs and not in others, presumably because the songs in which strong bass is heard are the ones that actually have strong bass in the mix and where it is not heard are the songs where the bass is not a large proportion of the mix.

The accurate sound without strong emphasis in any part of the spectrum is clearly evident in the B&W PI3 when compared to the sound of the Sony WF-1000XM3. In the Sony there is clearly an emphasis in the base, and the clarity and detail is not as good as the PI3. In fact the sound of the PI3 is so good, when the battery died on a Sony WH-1000XM4, which I had bought purely for its reputation as the best noise cancelling headphones, and I had to switch to the B&W PI3, the difference in sound was so stark, I returned the Sony WH-1000XM4 for a B&W PX7.

Bluetooth

Bluetooth performance is very good, beginning with the pairing experience. Powering the headphones for the first time immediately puts them in pairing mode. A second device can be paired easily by pressing the power button for 5 seconds. When coming back into range of previously paired devices, the headphones reconnect automatically with an announcement that even indicates whether it is the second device. This reconnection behavior is even customizable through the companion app.

Maintianing a connection is good when the device is a relatively close phone or a laptop. It is not so good with other devices that may not be as close or when there is some obstruction, such as a neck. In my case the connection is not so good with an LG TV that is 8 feet away when the headphones are worn normally, but improves when the around neck cable is moved from behind the neck to the front.

Battery Life

Battery life is good for headphones of this form factor at a solid eight hours. But as stated elsewhere in this article, unlike most other Bluetooth headphones, the headphones can be used while charging, either through a Bluetooth connection or through a wired mode through the cable that provides the charging. This makes the issue of battery life almost irrelevant as most users will be near a device that can provide a charge while using the headphones. Also, the headphones support quick charging, providing two hours of use with a 15 minute charge.

Linux

Linux performance with Bluetooth is trouble free; I was able to pair and connect on multiple distributions on the Plasma desktop. I was also able to control playback of YouTube videos on Firefox with Plasma Browser Integration enabled, Cantata, and the Spotify desktop application.

Sound quality is also excellent on Linux. This is despite the aptX apparently not being available on Linux at this time without manual sourcing of custom PulseAudio Bluetooth modules.

The one problem on Linux is that the wired mode through the USB-C cable connection does not work although the headphones are recognized by the Plasma desktop. When playing audio while the audio output is configured to the PI3 in digital mode (IEC598), even when the headphones are powered off, the level indicators and media players show that there is playback on the configured device but there is no output. Turning on the headphones allows faint and almost inaudible playback, but clicking the configuration setting page's test buttons results in clearly audible but very distorted playback.

The PI3 Shown in PLasma Desktop as a Wired and Bluetooth Device

Wired playback on Linux notwithstanding, the PI3 is usable on Linux through a Bluetooth connection without any problems. Even if audio is problematic with the wired connection, audio can be played back through Bluetooth while the headphones are charging through the USB-C connection.

Accessories

Included with the headphones are small, medium, and large sets of earbuds and stabilizer fins, a short USB-A to USB-C charging cable, and a cloth carrying pouch. B&W could have provided a hard case made small by requiring the headphones to be coiled ina manner similar to that suggested for storing them in the pouch, but for a soft pouch, those provided are very nice.

Bowers & Wilkins
The PI3 comes with three sets of earbuds and stabilizer fins, a short USB-A to USB-C cable, and a cloth pouch.

The closure is not a drawstring, as is usually the case for cloth pouch carrying cases for headphones, but a a mechanism consisting of spring loaded hinges and two flat semi-rigid plastic strips, that opens when pressure is applied on both hinges. The interior material is a microfiber cloth that seems, by feel, to be the interior layer of a three layer material, consisting of the outer cloth, a middle thin rubberized sheet, and the inner microfiber.

Chrooted Into the Arco Linux Installation

Unfortunately, some consideration must be taken when inserting the headphones in and some care taken when removing the headphones from the pouch. Because of the materials used in the lining of the pouch and the grippy silicone of the headphones themselves, there is some resistance with either inserting or removing the headphnes. When inserting it is actually easier to coil the headphones, not as the documentation suggests -- with the buds near the bottom of the coil, but such that the earbuds are near the top. When removing the headphones care must be taken so that the silicone earbuds and stabilizer fins are not unseated from the earphones.

Recommendation

I enthusiastically recommend the Bowers & Wilkins PI3. It excells in the one area that matters most for headphones -- the sound quality. The sound reproduction is suprisingly (becuse of the size of the headphones) rich and full without sacrificing clarity and detail in all regions of the audio spectrum. Bass reproduction is also strong, appreciable in songs that feature strong bass, without an artificial overemphasis. Characteristics secondary to audio quality, including the battery life, charge time, and Bluetooth connection. Of the secondary characteristics, the fact that they can be used while being charged is a standout.