Bowers & Wilkins PI5 S2 vs PI7 S2 Comparison Review

Bowers & Wilkins PI5 S2 vs PI7 S2 Review

I was pretty impressed with the Bowers & Wilkins PI5 S2 when I recently had the chance to review it, so I’m looking forward to seeing how it how it stacks up to the Bowers & Wilkins PI7 S2. Like the previous PI generation (now known as the S1’s), the PI7 S2 is the company’s more premium wireless bud offering geared towards an audiophile crowd. The PI5 S2, on the other hand, seems geared towards a more general audience. Let’s go over some of what has changed in the second generation of the PI’s before we jump into the different listening experiences that these wireless buds have to offer.

What’s In The Box?

Both the PI7 S2 and PI5 S2 come with nearly the same accessories:

• Bowers and Wilkins PI5 / PI7 S2 wireless buds
• Charging case
• 3 Pairs of Silicone Ear Tips
• USBC charging cable
• Safety Guide
• User Manual
• 3.5mm to USBC cable (PI7 S2 only)

Look and Feel

The PI7 S2 basically looks the same as the PI 5 S2 (and the S1’s), but is being offered in some new colors: Satin Black, Canvas White, Midnight Blue. The new colors offered for the PI5 S2 are Storm Grey, Cloud Grey, and Spring Lilac. Aside from these color options, the PI7 S2 and PI5 S2 have the same small, somewhat-ovular housing with a metallic, circular knob on the buds’ back faceplate. They look understated, smooth and cool. Both pairs of buds are easy, comfortable, and bound to fit a wide variety of ear shapes and sizes with their simple shape. The only minor difference is weight: the PI5 S2 is 6 grams, while the PI7 S2 is 7 grams.

Wireless Review and Specs, S1 and S2 Differences

Specs	Bower & Wilkins PI5 S2	Bowers & Wilkins PI7 S2
Battery	5.5 Hours, 19 hours in case, 15 minute quick charge =  2 hours playback	5 Hours, 16 hours in case, 15 minute quick charge = 2 hours playback
Bluetooth	5.0	5.0
Codecs	AAC, SBC, aptX	AAC, SBC, aptX, aptX adaptive, aptX HD
Microphones	2 per earbud	3 per earbud
Modes	ANC, Pass through (low and high), Passive	ANC, Pass through (user-controlled scale), Passive
Waterproof	IPX54 (Earbuds only)	IPX54 (Earbuds only)

The most significant upgrades found in the Bowers & Wilkins PI7 S2 from the S1 are an extra hour of playback battery life in the buds (5 hours now for the PI7 S2 and 5.5 hours for the PI5 S2), a faster charging time (15 minute charge providing 120 minutes of playback instead of 70), and an improved wireless antennae that improves signal strength and range (an extra 25 meters as reported by Bowers and Wikins).

The Bowers and Wilkins app has also seen a little bit of an upgrade. Users can now import streaming subscriptions and keep everything centralized to the app. Aside from this, the app can be used to turn ANC on and off, check bud battery life, and control pass through mode. On the PI5 S2, pass through simply has two volume modes: High and Low. The PI7 S2 offers some more nuanced control: pass through volume is controlled on a sliding scale in the app.

One of the most important differences between the two units is their codec compatibilities. Unlike the PI5 S2, the PI7 S2 is capable of playing 24 bit audio thanks to its more advanced aptX codec offerings. This seems pretty in line with the target audiences of the two buds: the PI7 S2 is well suited for the typical Qobuz user, while the more casual Spotify listener will be well served by the PI5 S2.

Like the S1’s, wireless retransmission from the case is available only for the PI7 S2. This feature can be utilized by using the 3.5mm to USBC cable to connect the charging case to an unbalanced source. This conveniently turns any audio device with a 3.5mm unbalanced output into a PI7 S2 compatible bluetooth device.

When it comes to mic call quality on both units, I don’t have a whole lot to say. Both the PI5 and PI7 S2 provided clear enough quality that my human-guinea-pig on the other end said was understandable and not unpleasant. However, the low end on voices was a bit  overemphasized, and a little bit of crunchy-phone quality was present. Not bad, not great.

At this point, I’ve gone over most, if not all, of the upgrades we’re seeing in the PI S2 generation: new colors, more bud battery life, faster charge time, and a better connection. These changes aren’t necessarily exciting changes where you can nerd out over differences in tuning and sound signature. A number of reviewers seem to express disappointment about this. Though I understand where they’re coming from, I think these are thoughtful and mature upgrades; Bowers and Wilkins put serious technical work in the PI series to impart a noticeably more convenient wireless performance instead of adding 2 dB to whatever frequency band and calling it a day. One upgrade I would have liked to see to make the second generation a bit more exciting is an in-app EQ to at least give users the choice of a new tuning (though I do like the house sound quite a bit). Alas, if Bowers and Wilkins ever ends up offering that, it will be in an S3 generation or later. 

Technical Design

Like the S1, the PI7 S2 is a unique wireless unit with a two driver crossover in each bud: a 9.2mm dynamic driver (like the one in the PI5 S2) for lows, and a balanced armature for highs. The PI5 S2 has a single 9.2mm dynamic driver, the same one used in the PI7 and PI5 S1. Here, we don’t see anything different from the S1 generation of Bowers & Wilkins buds. My only extra comment here is that it’s rare to come across multi-driver wireless buds. It’s impressive and exciting to see this in the PI7, even though this is no different from the PI7 S1.

Also, something I don’t see discussed much is the semi-open-back design(?) of both buds that was present in the PI S1 generation as well. There is some sort of either acoustic grill or mini speaker on the top of the buds that quietly leaks sound towards the pinnae of a listener’s ears. This is a feature I’ve seen on audiophile-tier IEMs, and I generally find it does great things in the way of imaging and sound stage. 

Sound Stage

As impressed as I was with the PI5’s stage and imaging, the PI7 takes it one step further. Depth is as abundant as it was with the PI5, but its width is far more vast and height becomes much more apparent. The opening, widely panned vocals on the track “Jara” by Fleet Foxes felt as though they originated from beyond the sides of my shoulders, and even felt as though they were angling up at me from below. The PI5 S2 still offered impressive spatial separation for this vocal part, but felt a bit closer to my head and had a more neutral feeling of height. Both units offered way more in the way of spatial separation than the vast majority of wireless buds that I’ve had the chance to try, but the PI7 S2 is a G.O.A.T. contender when it comes to wireless stages. This difference in stage sets the tone for the differences we’ll see throughout the sound of these two buds: the PI5 S2 is an impressive and fun bud, while the PI7 S2 is sophisticated, serious, and strives to be exceptional.

Lows

While both of these Bowers & Wilkins wireless buds have widely and heavily boosted low ends, the PI7 S2 is more modest and well controlled with its boost than the PI5 S2. The PI5 S2’s bass response gels well with pop, electronic, hip hop – mainstream genres that are oriented around their driving low end textures. For listeners who want wireless buds to listen to somewhat more niche/eclectic genres like folk, jazz, or neo-avant-garde-noise-fusion (or whatever it may be), they will likely find more of what they’re looking for with the PI7 S2. As I noted in my review for the unit, the PI5 S2’s low end brings somewhat of an unnaturally thick tone to instruments such as strummed acoustic guitars. The PI7 S2 still has some of this weight, but it’s more carefully distributed: more stock seems to be put into subs and mid bass than high bass. It also seems to handle its low end with greater speed and detail. The 7’s less emphasized low end relative to the 5’s makes sense for a tuning geared towards audiophiles, as it provides more clarity and tonal separation. 

Mids

The center frequency profiles on the two buds are fairly similar, but are contextualized differently by their low end balances. The Bowers and Wilkins PI7 S2 and 5 S2 both have a moderately V-shaped tone to their mids, . Though there’s a high-mid ramp in both of their tunings, the low-mids have a more prominent presence in their overall balances. Though I don’t think this imparts an outright muddy sound on either bud, the more modest low end on the PI7 S2 gives more clarity to this warm area of the frequency response and imparts a more natural sound onto vocals and guitars. As much as I love the fun and forceful qualities of the PI5 S2’s bass, a little clarity gets lost with the fierce competition between its subs, mid bass, high bass, and low mids. In the PI7 S2, the low mids have a little less competition with the low end, and do a better job retaining a sense of distinction and clarity.

Highs

In both Bowers and Wilkins wireless earbuds, there’s a welcome brightness in their high frequency response that supplies lift for otherwise heavy and dense balances. However, the PI7 seems to work its higher frequencies into its balance with greater ease. The PI5 S2’s low and mid treble could possibly be perceived as somewhat harsh by some listeners (not me personally) – particularly in the harmonic overtones on distorted guitars. Once again, the PI7 S2 seems to have an easier time with executing its balance, including its bright low and mid treble detail with a smoother and more natural quality. Both buds have a satisfying high treble extension that supplies vocal air, cymbal, and reverb details in a pleasant contrast to their thicker lows.  

Overall

The Bowers & Wilkins PI7 S2 and PI5 S2 make each others’ purpose self apparent in a direct comparison. The big, fun sound of the PI5 S2 is easy to imagine in the ears of more mainstream listeners who want maximum energy from the low end pulse of pop and electronic tracks, and will be pleasantly surprised by the depth of its layering. Alternatively, the PI7 S2 offers a more cautiously bassy sound that provides more clarity to critical listeners. The PI7 S2 ultimately has a more versatile balance with a bigger stage and more vivid imaging. Its 24 bit wireless audio capability is nothing to sneeze at, and goes a long way in justifying why it’s $100 more expensive than the PI5 S2. $400 nonetheless seems a bit pricey for audiophile-grade wireless buds, especially considering Noble Audio’s Fokus Mystique is going for $360 and Final Audio ZE8000 will soon be available for just about $350. With due time and patience, we’ll probably see PI7 S2 settle down to this price range; in the meantime, if you want a wireless bud that is as casual and comfortable as it is spacious and well-balanced, some-but-not-many can compete with the PI7 S2.

The Bowers and Wilkins PI5 S2 is available here and the Bowers and Wilkins PI7 S2 is available here from Audio46.

Bowers and Wilkins PI5 S2	BOTH	Bower’s and Wilkins PI7 S2
	Easy and comfortable fit
	Smooth and cool look
Sound stage offers impressive depth, adequate width	Great imaging that provides clear separation	Soundstage offers impressive depth, width, and elements of height
Louder bass and more high bass than the PI7 S2	Heavy bass	Less bass and narrower bass boost than the PI5 S2
Less low end/low-mid distinction than the PI7 S2	V shaped mids, low-mid emphasis	More low end/low-mid distinction than the PI5 S2
	Solid treble presence
4.5 hour playback battery in buds is now 5 hours	More playback battery life in the buds	4 hour playback battery in buds is now 5 hours
	15 minute quick charge delivers 120 minutes playback instead of 70 minutes.
	Better wireless connections
16-bit wireless audio		24-bit wireless audio and wireless retransmission from case