Compare Bose SoundLink Flex Portable Speaker, 2nd Gen vs Soundcore Boom Go 3i

Audio format support is supported by SBC, AAC, aptX and higher-quality Android streaming references.

Backward compatibility is weak because multiple reviewers state the second-generation model cannot stereo-pair with the original Flex.

Backwards compatibility is a weakness because reviews state it is not compatible with PartyCast-only devices and cannot pair with some older Soundcore PartyCast models.

Battery life is adequate but not a highlight, with reviewers citing up to 12 hours and much shorter runtime at high volume or in tests.

Battery evidence is strong but context-dependent: reviews cite up to 24 hours, up to 40 hours in Eco mode, roughly 6 hours at max with lights, and one 12-hour real-world result at 75%.

Codec support is a meaningful Gen 2 upgrade, with reviewers citing Snapdragon Sound, aptX, SBC and AAC support.

Codec evidence is limited to one review, which reported SBC and AAC support.

Bluetooth connection stability is praised by several reviewers, with notes on Bluetooth 5.3, Snapdragon Sound, no hiccups and no disconnections.

Bluetooth range is only lightly covered, with one spec citing 30 feet and another reviewer saying they could walk a good distance before issues.

One review cited about a 30 m Bluetooth range, giving limited but positive range evidence.

Cabinet construction is praised through metal or steel grille references plus rubberized, silicone or aluminum casing materials.

Construction is a strength, with reviewers praising thick dense plastic, a sturdy-feeling body, and nice build quality.

Charging is a recurring weakness: reviewers repeatedly cite about four hours to recharge, which some call slow or disappointing.

Charging-time evidence is mixed and limited, with emergency phone charging described as slow but speaker quick-charge use also mentioned.

Cohesive presentation is strong overall, with reviewers describing the sound as balanced, full, clear or unexpectedly capable for the size.

Overall presentation was positive but not audiophile-grade, with reviews calling it good sounding, capable, and effective for its class.

Controls are mixed: some found them easy, but SoundGuys called the buttons mushy and Android Police found touch operation confusing.

One hands-on review reported the physical controls worked after testing, but detailed long-term button responsiveness evidence is limited.

Design and aesthetics are a major consensus strength, with repeated praise for the premium feel, colors, slim body and attractive grille.

Design feedback was generally positive for its compact, rugged, puck-like build, rubber body, feet, and clean design, despite some stand-up limitations.

Detail retrieval is a strength for the size, with reviewers hearing crisp detail, nuance and separated musical layers.

Detail retrieval is only moderate because reviews specifically noted weaker instrument separation from the single-driver design.

High-volume behavior is mixed: some reviewers say Bose processing keeps distortion controlled, while others heard clarity drop or distortion at higher volumes.

High-volume comments were mostly positive on clarity, but reviewers noted the speaker preserves clarity by letting bass fall back at louder levels.

Durability is strong, with reviewers citing rugged construction, drop-proof claims, solid feel and protection against outdoor abuse.

Drop durability is a strength across reviews, with one-meter/drop-proof claims and real drop testing where the speaker kept working.

Dust resistance is strongly supported by repeated IP67 and dustproof references across the reviews.

Dust resistance is a clear strength, with repeated IP68 evidence and review language calling it fully dustproof or dust and waterproof.

Dynamic headroom is supported by TechRadar's bass comments, though the broader evidence suggests dynamics are good for size rather than huge.

Dynamic headroom is supported by claims of headroom and dynamic sound with BassUp, though evidence is limited to two reviews.

Energy efficiency is only lightly supported, with one reviewer noting effective sleep behavior that avoids unnecessary battery drain.

Eco mode and lights-off operation support better efficiency, with reviews saying these settings extend battery life substantially.

EQ customization is one of the clearest upgrades, but reviewers generally describe it as useful while limited to basic bands or presets.

EQ customization is a major strength because many reviews mention Soundcore app EQ presets, custom EQ, and BassUp control.

Everyday usability is strong for desks, bedrooms, travel, poolside use and small gatherings thanks to the compact design and easy operation.

Everyday use was rated highly because reviewers repeatedly described easy carry, bag use, outdoor use, attachment options, and real-life convenience.

Float capability is directly praised by multiple reviewers, who note the speaker floats if dropped in water.

Float capability is weak because one review explicitly said the Boom Go 3i does not float upright.

Most reviewers describe the sound as balanced, clear or full, with punchy bass for the size but not true party-speaker low end.

Sound balance was generally described as good or respectable for the size, with usable bass and mids, though some reviews noted limited bass compared with rivals.

The fabric loop or strap is useful for bags and hooks, though one reviewer wanted a more flexible loop or included carabiner.

The strap was a major strength: reviews praised its clip/strap modes, backpack and bike mounting, and two-position versatility.

Home theater integration is limited but present through Bose SimpleSync with compatible Bose smart speakers or soundbars.

Inter-speaker connectivity is supported through Bose speaker linking, stereo mode and party mode, but compatibility limits reduce flexibility.

Inter-speaker connectivity is supported through stereo/TWS and Auracast options, especially with another Boom Go 3i.

Latency is mostly described positively for video and streaming, though one reviewer still noticed a minor amount of video latency.

Two reviews said latency was not an issue for phone video viewing, which supports acceptable lip-sync behavior for casual video use.

The LED/RGB lighting was repeatedly praised as customizable, beat-synced, visible, and useful for SOS or night visibility.

Lighting effects were a distinctive strength, with reviews praising music sync, ambient modes, RGB colors, visibility, and customization.

Reviewers say the Flex 2 gets loud enough for rooms, yards and small outdoor groups, but several note it is not the loudest or best for large spaces.

Reviewers consistently found the Boom Go 3i loud for its compact size, with 15W output and a 92 dB claim, though one review framed it as small-speaker loud rather than party-speaker loud.

Low-volume performance is only lightly supported, but TechRadar specifically heard clearer vocals at lower volume levels.

Lower-volume usability is positive: reviewers said 50% volume was decent, and one comparison said output differences remain noticeable at 25% or 50%.

Magnetic mounting is a weakness because comparison reviews identify magnetic mounting as a rival feature rather than a Boom Go 3i feature.

The built-in microphone is confirmed for calls and assistant access, though call quality evidence is limited.

The microphone situation is weak for calls: reviews repeatedly say there is no built-in mic, though the app can use a phone for voice amplification.

Pairing reliability is generally positive when using compatible Bose speakers, though the ecosystem is limited and not backward-compatible with the original Flex.

Pairing two matching units worked well in one review, but Auracast/PartyCast and JBL compatibility issues made multi-speaker reliability mixed.

Multipoint is repeatedly confirmed, letting the speaker connect to two devices or manage multiple sources through the Bose app.

Two reviews said it can connect to two Bluetooth devices at once, making multipoint a supported strength.

Omnidirectional sound is a weakness; Tom's Guide specifically describes strong directionality and a narrow soundstage.

The speaker is more directional than omnidirectional, with one review describing a frontward-firing driver and passive radiators.

On-device controls are generally useful and complete, but touch-finding and button feel vary by reviewer.

On-device controls are practical, with top buttons for volume/playback and direct track controls noted in reviews.

Power-bank support is absent; reviewers explicitly say it cannot charge a phone or other devices.

The power-bank feature is widely noted as a useful emergency backup for topping up a phone, though not a full replacement power bank.

Value opinions are mixed: several reviewers say the quality justifies the price or sales help, while others call it expensive or a Bose tax.

Value was one of the most consistent positives, with reviews citing $60-$80 pricing, sale prices, and strong feature value.

Setup receives direct positive support from one reviewer who called it easy to set up and easy to use.

Setup evidence is positive but brief, with reviews calling Bluetooth pairing easy or real simple.

The shortcut button can access a phone voice assistant, but reviewers frame this as basic phone-assistant access rather than a full built-in assistant.

Smart features are limited: reviewers mention app controls, shortcuts, Spotify options and voice-assistant access, but repeatedly describe the feature set as lean.

Smart features are unusually broad for the size, including app controls, lighting, alarm, voice amplifier, workout timer, and sound effects.

Speakerphone quality is only lightly supported, with one reviewer saying the microphone works fine for quick calls but does not sound amazing.

Speakerphone quality is poor because several reviews said there is no built-in microphone or speakerphone for calls.

Status indicators are only lightly covered, with SoundGuys noting a status light above the shortcut button.

Status feedback is a strength, with several reviews praising the battery/status display as more informative than simple LEDs.

Stereo and imaging evidence is mixed: two-unit stereo mode can add separation, but the single speaker is directional and not especially wide.

The speaker is described as a 15W mono unit, so stereo imaging is inherently limited unless paired with another unit.

USB-C charging is consistently confirmed, though reviewers also note the port does not provide wired audio or power-bank output.

USB-C charging is supported, but reviews also emphasize that the port is exposed or charging-only rather than a wired input.

Value for money is mixed but generally acceptable: reviewers praise quality for the price while noting cheaper rivals exist.

Value-for-money evidence was especially strong when sale pricing was mentioned, including $49-$60 prices and favorable comparison value.

Vocals are consistently described as clear, easy to hear or delicate, supporting strong voice clarity for music and spoken content.

Vocal reproduction was called well pronounced in two reviews, supporting good voice clarity for music playback.

Water resistance is a major strength: reviewers repeatedly cite IP67 protection or water immersion suitability.

Water resistance is a clear strength, with repeated IP68 evidence and one review stating it can survive being submerged.

The speaker is widely praised as slim, light and bag-friendly, with reviewers repeatedly saying it is easy to carry or pack.

Reviewers repeatedly described it as lightweight or about 380 g, with bag carry still easy despite its small-speaker weight.

Wired playback is a clear weakness: reviewers repeatedly state there is no 3.5mm jack and USB-C is for charging, not audio.

The USB-C port is repeatedly described as charging-only, so wired audio input is effectively absent.