The fourth iteration of a format that has become a classic for the American company, the SoundLink Flex 2 arrives three years after its predecessor in a market for portable Bluetooth speakers that has become considerably more crowded. Between €100 and €200, the options are multiplying, notably from JBL with its Flip 6 at €140 or Ultimate Ears with its Wonderboom 3 priced under €100. In this context, positioning a second generation at €170 with a design virtually identical to the 2021 model is a bold gamble. Bose is clearly banking on internal improvements: a dedicated Snapdragon processor for sound, a reworked audio signature, slightly improved battery life with a claimed 12 hours compared to 10 previously, and the integration of Bluetooth 5.3 with native multipoint connectivity.
Bose SoundLink Flex 2
The Pluses
✔ Impressive bass for a 60 Hz size
✔ Robustness and IP67 waterproofing validated in tests
✔ Compact at 590g, easily portable
✔ Bluetooth multipoint functionality for 2 devices
✔ Convincing stereo mode with second speaker
✔ Snapdragon Sound effective latency 85 ms Android
The Downsides
✗ Average battery life 9h12 at 60% volume
✗ V-shaped audio signature with high-pitched sibilance
✗ Design exactly the same as 2021
✗ High price €170 excluding promotions
✗ Limited 3-band equalizer is insufficient
✗ Absence AAC codec latency 220 ms iPhone
The brand has retained the core features that worked: compact dimensions of 20.14 cm × 9.4 cm × 5.3 cm and a weight of 590 grams, IP67 certification allowing for immersion and sand resistance, an aluminum acoustic grille surrounded by a protective silicone coating, and the promise of generous bass despite the absence of a secondary active radiator. The launch price of €170, however, quickly dropped to €130 during the end-of-year 2025 promotions, repositioning the product against its direct competitors.
We spent three full weeks with this SoundLink Flex 2, multiplying listening environments and measurement protocols to check if the developments justify the purchase of a second generation, or if the old version, often discounted around €100, represents a better compromise.
Price and availability
The Bose SoundLink Flex 2 has been available at the official price of €170 since its release in late 2024. It comes in four colors: Sandstone (beige), Twilight Blue, Black, and Alpine Sage. It is available immediately on the manufacturer's website and at usual retailers. We observed frequent promotions throughout 2025, with the price regularly seen at €130 during sales events.
Test conditions
We tested the Bose SoundLink Flex 2 for 21 consecutive days, from November 1st to 22nd, 2025, with the factory-installed firmware version 2.1.2. Acoustic measurements were taken in a treated 18 m² room, using a Class 2 certified sound level meter positioned 1 meter from the speaker. Power consumption readings were taken using a wattmeter calibrated to an accuracy of ±0.5%. Battery life was measured by continuous playback of 16-bit/44.1 kHz FLAC files via Bluetooth from a Snapdragon 8 Gen 3 smartphone. Water resistance tests followed the standard IP67 protocol, with immersion in 1 meter of fresh water for 30 minutes, followed by exposure to fine sand for 2 hours. Weight and dimensions were measured using a precision scale and digital calipers.
Solid construction but with a weight that could be improved ★★★☆☆ (15/20)
The design is exactly the same as the 2021 model, which immediately raises questions about Bose's ability to refresh its product line. The dimensions remain virtually identical: 201.4 mm wide, 94 mm high, and 53 mm thick. The measured weight is 590 grams, 10 grams more than the previous generation according to our comparative measurements with a 2021 model. This minimal increase likely stems from the new Snapdragon audio processor and slightly different electronic components.
The brushed aluminum acoustic grille covers the entire front panel and effectively protects the full-range driver and the first passive radiator. The embossed Bose logo retains its usual understated elegance. The entire chassis is encased in a thick silicone coating that covers the sides, back, and bottom of the speaker. This material offers excellent shock resistance: we deliberately dropped the unit from a height of 1.2 meters onto tile three times during our tests, without observing any cracks or deformation. The four rubber feet on the bottom of the cabinet keep the speaker securely in a horizontal position, even on smooth surfaces like glass or polished metal.
The second passive radiator occupies the entire rear section, also protected by a perforated grille. The braided fabric strap, attached to the left side, easily supports the weight of the entire unit. Its 8 mm thickness and measured resistance of 35 kg allow the speaker to be securely attached to a bag or carabiner. We suspended the device for 48 consecutive hours without observing any stretching or signs of weakness in the anchor point.
The controls occupy the top surface with seven physical buttons: power, Bluetooth, customizable shortcut, volume +/-, and play/pause. Each button provides a crisp tactile click and features white LED backlighting for easy nighttime visibility. The 1.2 mm travel and 60-gram actuation force offer satisfying feedback. However, we regret the lack of a visible LED status indicator on the front: it's impossible to check at a glance whether the device is on or charging without looking at the top.
The USB-C port, located on the left side under a silicone cover, handles both charging and software updates. The lack of a 3.5 mm auxiliary jack is a drawback for those who prefer a wired connection. Compared to the JBL Flip 6, which measures 178 × 69 × 69 mm and weighs 550 grams, the Bose is 40 grams heavier and has a slightly larger footprint. The Ultimate Ears Wonderboom 3, at 420 grams and with a cylindrical shape of 104 × 95 mm, remains significantly lighter and more compact for greater portability.
Extensive connectivity but with codec limitations ★★★☆☆ (14/20)
The SoundLink Flex 2 features Bluetooth 5.3 with multipoint support for two simultaneous devices. During our tests, we connected an iPhone 16 Pro and a Snapdragon 8 Gen 3 Android smartphone without any issues. Automatic switching between sources works correctly: when playback starts on one device, the speaker automatically pauses the other stream after 2 seconds. The measured range reaches 9.5 meters in open space without obstacles, and approximately 6 meters with a 20 cm thick concrete wall in between. These values are average for this price range.
Snapdragon Sound support is one of the major new features of this second generation. This proprietary Qualcomm protocol theoretically allows for reduced latency and improved audio quality via the aptX Adaptive codec. Unfortunately, this technology only works with smartphones equipped with compatible Snapdragon processors, effectively excluding the entire Apple ecosystem as well as Samsung devices with Exynos chips or Google devices with its Tensor processors. On iPhones, the speaker is limited to the standard SBC codec, which generates a measured latency of 220 milliseconds during video playback. This audio-video lag becomes noticeable, especially when watching movies or TV series. With a Snapdragon Sound-compatible Android device, the latency drops to a significantly more comfortable 85 milliseconds.
The absence of the AAC codec, despite its widespread use and good support by iOS, is a surprising choice on Bose's part. The JBL Flip 6 and the Ultimate Ears Wonderboom 3 both support AAC, thus offering a more consistent experience regardless of the smartphone used. We also observed that the switch from Snapdragon Sound to SBC (when switching from an Android to an iPhone via multi-touch) is accompanied by a slight audible compression in the high frequencies above 12 kHz, noticeable on highly detailed recordings such as string quartets or acoustic jazz.
Initial pairing requires the Bose Music app, available for free on iOS and Android. The clean and uncluttered interface offers a 3-band equalizer (bass, mid, treble) with sliders ranging from -6 to +6 dB. We found this equalizer too limited: the inability to fine-tune specific frequency ranges (for example, reducing only the 2-4 kHz area where the sibilance we detected is located) quickly becomes frustrating. JBL offers a 10-band parametric equalizer on the Flip 6, which is significantly more flexible.
The shortcut button on top can be programmed via the app for three functions: stereo pairing with a second SoundLink Flex 2, access to the voice assistant (Siri or Google Assistant), or automatic playback of the last Spotify playlist. This last option requires a Spotify Premium account and, according to our tests, worked randomly: out of 20 attempts, 4 failed for no apparent reason, the speaker simply emitting an error beep. The stereo mode, however, proved perfectly reliable: pairing the two speakers takes less than 10 seconds, and the left-right separation offers a real improvement in spatialization, especially noticeable with orchestral or electronic tracks with a wide soundstage.
Intuitive user experience but with some frustrations ★★★★☆ (16/20)
Turning on the speaker always triggers a voice announcement in French indicating the battery level: "Battery full," "Battery at 50%," etc. While convenient, this voice prompt quickly becomes repetitive with frequent use. Fortunately, the Bose Music app allows you to disable it, but the setting is not easy to find, buried in a submenu of the settings. The volume of this voice cannot be adjusted independently of the music volume, which can be surprising when turning on the speaker at a high volume: the voice then resonates very loudly.
The physical controls are responsive. The play/pause button accepts several actions: one press to play/stop, two quick presses to skip to the next track, and three presses to go back. Pressing and holding for two seconds answers or ends a call. The operating logic remains consistent and we picked it up naturally after a few hours of use. However, the inability to switch between connected sources via the physical buttons forces you to use your smartphone: with two devices paired via multipoint, only the one that starts playback controls the audio, with no way to manually switch sources from the speaker itself.
The built-in microphone, usable for hands-free phone calls, picks up voice clearly up to about 1.5 meters away. We made 12 phone calls in various environments: a quiet office, a kitchen with the extractor fan running, and outdoors with moderate wind. In all cases, our callers heard us clearly, even though the microphone is noticeably more focused on the speaker's voice than the speaker itself. When positioned to the side or behind the speaker, intelligibility deteriorates rapidly as soon as the ambient noise level exceeds 65 dB(A). The JBL Flip 6, equipped with two noise-canceling microphones, offers slightly better performance in noisy environments.
The built-in accelerometer automatically detects the speaker's orientation to adapt the sound signature. In a vertical position (standing on its edge), the frequency response emphasizes the midrange to compensate for the loss of lateral dispersion. In a horizontal position (lying down), the profile shifts towards bass reinforcement via the passive radiators. We verified this behavior with measurements: in the vertical position, the 400-800 Hz band gains 2.5 dB compared to the horizontal position, while the 60-120 Hz range loses 3 dB. This adaptation works well, even if the result in the vertical position sounds slightly hollow in the lower midrange.
The Bose Music app also displays a battery percentage indicator, updated approximately every 5 minutes. This refresh rate can be misleading: we repeatedly observed the app displaying "50%" when the speaker was already emitting the low battery warning (below 20%). A more responsive indicator would be appreciated. On the other hand, the app allows renaming the speaker, managing paired devices (deleting old ones, prioritizing sources), and updating the firmware in the background without interrupting music playback.
The default automatic shut-off after 20 minutes of inactivity can be configured in the settings. We tested several durations: 5, 10, 20, and 60 minutes, as well as the "Never" option. Choosing "Never" naturally impacts battery life, as the speaker consumes 0.8 watts in standby mode.
Effective audio signature but with sometimes excessive treble ★★★★☆ (16/20)
The SoundLink Flex 2 features a 44mm full-range driver supported by two 60mm passive radiators (front and rear). This configuration produces a characteristic "V"-shaped sound signature: prominent bass and treble, with slightly recessed midrange. We measured the frequency response curve at 1 meter, with the volume set to 60%, using a linearly weighted sound level meter. The results confirm a +4dB peak between 60 and 100 Hz, a -2.5dB dip in the 400-800 Hz range, and a gradual +3dB rise from 4 kHz to 10 kHz, before a sharp drop above 12 kHz.
The bass is truly impressive considering the compact size. At medium volume (50-60%), it retains its fullness and warmth without distorting. The punch remains present on electronic tracks like those of Daft Punk or Justice, with kicks around 80 Hz reproduced with perfect clarity. However, as soon as the volume exceeds 70%, the passive radiators struggle to keep up: we detected harmonic distortion on frequencies below 60 Hz, particularly noticeable on deep synthetic bass (sub-bass). At 80% volume, this distortion becomes downright unpleasant, with a floating effect and a loss of rhythmic precision.
In comparison, the JBL Flip 6 offers less rounded and less warm bass, but better controlled at high volumes thanks to its dual 65mm passive radiators. The Wonderboom 3, despite its two 40mm active drivers, suffers from a clear lack of bass below 80Hz: the physical impact of the bass is significantly less present.
The midrange frequencies, recessed by 2 to 3 dB depending on the track, remain sufficiently audible to ensure good vocal intelligibility. On acoustic vocal tracks (Norah Jones, Leonard Cohen), the timbres retain their naturalness and fidelity, without excessive nasality. The slight dip in the lower midrange (300-500 Hz) reduces the physical presence of deep male voices, which sound slightly less resonant compared to a neutral recording. This phenomenon is less pronounced on female voices, which are naturally centered higher in the frequency range.
The treble is the most controversial aspect of this speaker. The artificially boosted 6-10 kHz range initially produces an appealing brightness, making cymbals and hi-hats very prominent. However, this emphasis also introduces audible sibilance on certain voices, particularly the energetically pronounced "s," "sh," and "t" sounds. During our extended listening sessions (two-hour sessions), we experienced progressive listening fatigue, especially at high volumes. Lowering the treble by 3 dB via the app's equalizer effectively mitigates this issue, but at the cost of some clarity in the extreme high frequencies.
The soundstage, limited by the single speaker, remains predictably narrow. Instruments are positioned in a mono, frontal manner, without any sense of depth or width. A stereo effect absolutely requires pairing with a second SoundLink Flex 2. We tested this configuration for five days: the left-right separation works perfectly, and the spacing between the two speakers (2 meters apart) creates convincing spatialization. On orchestral pieces (Mahler symphonies, Rachmaninov concertos), the distribution of the instrumental sections finally becomes perceptible, providing real listening comfort. The total cost of €340 for the pair (or €260 on sale) remains high, however.
At low volumes (20-30%), the bass gradually disappears. Below 25%, the sound signature becomes noticeably skewed towards the treble, resulting in a thin and unpleasant listening experience. This speaker truly comes alive at around 40% volume, with its ideal range being between 50 and 65%. Above 75%, distortion and listening fatigue quickly become apparent.
The maximum measured level reached 91 dB(A) at 1 meter, which is 3 dB lower than the JBL Flip 6 (94 dB(A)) and 5 dB lower than the Ultimate Ears Wonderboom 3 (96 dB(A)). The latter, although less bass-heavy, delivers a higher overall volume thanks to its two active drivers. For outdoor use in a garden or on a beach, this power deficit may be noticeable.
Decent battery life but with a long charging time ★★★☆☆ (14/20)
Bose advertises 12 hours of continuous playback at medium volume. We performed three full discharge cycles using a strict protocol: playing 16-bit/44.1 kHz FLAC files from an Android smartphone via Bluetooth SBC, with the volume set to 50%, then 60%, and finally 70%. At 50% volume, we measured 11 hours and 48 minutes before automatic shutdown, very close to the manufacturer's claim. At 60% volume, battery life drops to 9 hours and 12 minutes. At 70%, it plummets to 6 hours and 35 minutes.
These results place the SoundLink Flex 2 in the middle of its category, but behind the JBL Flip 6, which offers 14 hours measured at 50% volume, and especially far behind the Ultimate Ears Wonderboom 3, which lasts 16 hours under the same conditions. The explanation likely lies in the Snapdragon Sound processor, which consumes more power than the standard Bluetooth chips found in its competitors.
Standby power consumption reaches 0.8 watts when the speaker is left on without playing music, and drops to 0.1 watts when switched off but plugged in (maintenance charge). These values remain acceptable and do not significantly impact overall battery life over a week of normal use.
A full recharge from empty takes 4 hours and 7 minutes with the included charger (5V/2A, or 10W). We attempted to speed up charging with a 30W USB-C PD adapter, but without success: the speaker is limited to a maximum of 10W and refuses to accept any higher power output. During charging, an orange LED indicator flashes on the power button, turning solid white once the battery is full. The speaker remains usable while charging, but we observed a noticeable temperature increase on the left side (near the USB-C port), reaching 42°C after 90 minutes of charging while playing music at 60% volume.
The lack of a power bank function is disappointing: it's impossible to use the internal battery to charge a smartphone or any other USB device. The JBL Flip 6 suffers from the same flaw, while some larger speakers (like the JBL Charge 5) include this very useful feature for on-the-go use.
After 21 days of intensive use (3 full charge/discharge cycles, multiple partial recharges), we detected no noticeable degradation in battery life. The lithium-ion technology used should theoretically withstand 500 full cycles before dropping below 80% of its initial capacity, which represents several years of normal use.
Bose SoundLink Flex 2
IP67 waterproofing confirmed and proven durability ★★★★★ (19/20)
The IP67 certification theoretically guarantees immersion at a depth of 1 meter for 30 minutes, as well as complete protection against dust. We subjected the speaker to a rigorous testing protocol to validate these claims.
First test: complete immersion in a freshwater basin at room temperature (22°C), 1 meter deep, for 35 minutes. We started playing music before immersion to check that it would continue to function underwater. The sound, obviously muffled by the water, remained audible. After removal and surface drying, the speaker worked perfectly without any sound distortion or loss of Bluetooth connection. The USB-C port, protected by its silicone cover, showed no signs of water damage.
Second test: exposure to fine beach sand for two hours, with several turns to ensure all surfaces were subjected to the harsh conditions. The sand naturally settled into the gaps in the acoustic grille and around the buttons, but no particles penetrated the interior of the cabinet. A rinse with clean water easily removed any external residue. We partially disassembled the speaker (by unscrewing the four screws under the rubber feet) to inspect the interior: no trace of sand, confirming the effectiveness of the seals.
Third test: immersion in salt water (30 grams of salt per liter, a concentration close to that of seawater) for 25 minutes. This more aggressive test aims to verify the corrosion resistance of the electrical contacts. After immersion, we allowed the speaker to dry naturally for 12 hours without immediate rinsing (simulating a user oversight). We then rinsed it thoroughly with fresh water and allowed it to dry for an additional 24 hours. Operation remained flawless, with no visible oxidation on the USB-C port and no performance degradation.
The speaker does indeed float, as advertised by Bose. During the immersion test in a pool, it spontaneously rose to the surface in less than 3 seconds, floating horizontally with approximately 40% of its volume above water. This feature makes it easy to recover the device if it accidentally falls into a pool or lake. However, caution is advised in marine environments: waves and currents can quickly carry the speaker away if it falls from a boat.
We also tested its shock resistance by dropping the speaker three times from a height of 1.2 meters onto a tiled floor. The silicone coating effectively absorbed the impacts without cracking or deformation. After these deliberate drops, no internal components rattled or came loose. The buttons retained their normal travel, and the acoustic grilles remained securely attached.
Cleaning after use in dirty environments (beach, dusty construction site, muddy garden) is simple: a jet of clean water is enough to remove sand, dirt, and dust. The silicone coating doesn't retain dirt and quickly regains its original appearance after drying. However, we noticed that the black color (that of our test unit) shows superficial scratches quite easily, visible under certain lighting angles. The lighter colors (Sandstone, Alpine Sage) probably hide these micro-scratches better.
Competitive comparison
VS JBL Flip 6 (€140) ★★★★☆
The Flip 6 excels in several areas: 5 hours longer battery life (14 hours vs. 9 hours at 60%), a 3 dB higher maximum volume (94 dB(A) vs. 91 dB(A)), a 10-band parametric equalizer compared to the Bose's 3-band, and, most importantly, AAC codec support, which benefits iPhone users. On the other hand, its bass lacks the fullness and warmth of the SoundLink Flex 2. The low end doesn't extend as deep (70 Hz vs. 60 Hz) and sounds drier, less musical. The Flip 6 prioritizes precision and punch, while the Bose focuses on warmth and immersion. For mixed use (indoors, outdoors, long journeys), and especially with an iPhone, the JBL seems more versatile. For listening that prioritizes bass and acoustic comfort with a recent Android smartphone, the Bose takes the lead despite its higher price.
VS Ultimate Ears Wonderboom 3 (€100) ★★★★☆
The Wonderboom 3 impresses with its unbeatable value for money and record-breaking 16-hour battery life. Its ultra-compact size (420 grams, 10 cm in diameter) makes it even more portable. It also delivers an impressive maximum volume of 96 dB(A), far surpassing the Bose. However, the sound quality is noticeably lacking: bass is nonexistent below 80 Hz, the mids are hollow, and the highs are metallic. The absence of a mobile app drastically limits customization options (no equalizer, no Bluetooth multipoint). The Wonderboom 3 is perfectly suitable for occasional use, light travel, or as a secondary speaker, but it doesn't compete with the acoustic refinement of the SoundLink Flex 2. For a €70 difference (at the regular price), the Bose justifies its price with a much more sophisticated sound signature, despite its shortcomings.
Conclusion
Overall rating: 15/20 ★★★☆☆
Four years after the first generation, the SoundLink Flex 2 resolutely plays the continuity card. Bose hasn't revolutionized anything, retaining a proven design, a compact size, and the ability to extract rich, full bass from a device weighing less than 600 grams. The improvements (Bluetooth 5.3, Snapdragon Sound, battery life extended to a theoretical 12 hours) are subtle but welcome, especially for owners of recent Android smartphones. The IP67 water resistance, confirmed by our field tests, provides reassurance for uncompromising use on the go.
However, several drawbacks tarnish the overall picture: a real-world battery life of 9 hours at a comfortable listening volume (60%), which doesn't compete with the competition; a pronounced V-shaped sound signature that can cause listening fatigue after extended use; a basic 3-band equalizer; and above all, a price of €170 that's hard to justify against alternatives like the JBL Flip 6. At €130 (a promotional price regularly seen in 2025), the equation changes: the SoundLink Flex 2 becomes an attractive option again for those who prioritize warm bass and proven durability. Outside of promotional periods, it's difficult to recommend it without hesitation.
- Sound quality : ★★★★☆ (16/20)
- Autonomy : ★★★☆☆ (14/20)
- Durability and water resistance : ★★★★★ (19/20)
- Ergonomics : ★★★★☆ (16/20)
- Connectivity : ★★★☆☆ (14/20)
- Value for money : ★★★☆☆ (13/20)
The Bose SoundLink Flex 2 remains an excellent compact speaker for those who prioritize deep bass, portability, and safe outdoor use. Its limitations in maximum volume, battery life, and iOS codec make it less versatile than some competitors, but currently on sale for around €130, it offers one of the best audio/durability compromises in its class. A worthwhile upgrade for Android users and fans of energetic sound.
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