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

The Soundcore app is consistently described as useful, easy, deep, or quick to connect, with no reported reliability failures in the reviews scored here.

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 weak where discussed because one review says it cannot pair with older Boom-series 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 life is broadly good but context-dependent: reviewers cite a 16-hour claim, while real-world tests drop to about 6 to 14.7 hours with lights, volume, and BassUp active.

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

Codec evidence is limited but positive, with reviewers noting Bluetooth 5.3 support alongside AAC, SBC, or AAC specifically.

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

Connection stability is strong in the reviews that tested it, with no dropouts reported in one long test and strong range through walls in another.

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

Bluetooth range is above typical portable-speaker expectations, with multiple reviewers citing or testing around 100 feet and another reporting a strong signal over distance.

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

Reviewers describe a solid plastic shell, protective grille, rubberized bumpers or feet, and generally rugged construction that suits outdoor use.

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

Charging is straightforward over USB-C, with reported recharge times ranging from three to four hours.

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

The Boom 3i generally holds together as a fun outdoor speaker, though the most critical review finds the core audio less cohesive than its rugged feature set.

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

Physical controls receive positive marks where discussed, including easy coverage of essentials and responsive tactile operation.

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

Design impressions are mixed: some reviewers like the compact, solid, colorful look, while others call the industrial grille polarizing or unattractive.

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

Detail retrieval is mixed; several reviewers praise vocal, midrange, or treble detail after EQ, while PCMag reports orchestral details becoming hard to discern.

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 behavior is mixed: some reviewers report bass holding up well, while others hear crispiness, garbling, muffling, or distortion at higher levels or in water.

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

Durability is one of the strongest points, with repeated evidence for drop resistance, tough plastics, rubber protection, and outdoor abuse tolerance.

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

Dust protection is well supported through IP68 references and dustproof descriptions, with several reviews also noting sand or dust removal features.

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 only moderately supported: one detailed review finds above-average dynamics for size but lost nuance at high volume, while PCMag hears compression.

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

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, with repeated mentions of presets, custom EQ, a nine-band EQ, and user control over tuning.

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

Everyday usability is strong for a rugged speaker, with reviewers using it at home, camping, traveling, and on the go rather than only at the pool.

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

Float capability is the clearest consensus strength; reviewers repeatedly note upright floating playback that keeps the drivers facing upward.

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

Frequency balance is fun and bass-forward rather than neutral; many praise the bass and clarity, but some note dark, muffled, harsh, or less refined default tuning.

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

The strap and carry hardware are generally useful for travel, kayaking, hanging, and hands-free transport, with only minor concern about loose strap pieces.

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

Home theater integration has limited but real support from one review that used it successfully with a projector as an extra speaker.

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

Inter-speaker connectivity is a strength, with evidence for TWS stereo pairing and PartyCast support across many reviews.

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

Latency is generally good enough for video viewing, though one reviewer finds slight lag and warns against serious mobile gaming.

LED lighting is frequently mentioned as a fun, visible feature, though one reviewer found the backlight too intense and some kept it off.

Lighting effects are customizable and app-controlled in several reviews, with brightness, modes, rhythm syncing, and color controls noted.

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.

Maximum volume is strong for the size, with many reviewers citing 50W output, high dB claims, and good outdoor or small-room loudness.

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

Low-volume evidence is limited but positive, with one review noting clear audibility at minimum camping volume.

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

The voice-amplifier feature relies on the phone as a microphone, so microphone-related usefulness exists but not as a built-in speakerphone mic.

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

Pairing reliability has positive but limited evidence: reviewers appreciate the direct pairing button and one TWS demo connects very quickly.

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

Multipoint support is repeatedly mentioned, with reviewers noting two-device connection for shared DJ use.

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

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

On-device controls are well covered, with physical buttons or touch controls for playback, volume, lights, BassUp, Bluetooth, and pairing.

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

Power-bank functionality is a clear weakness because reviewers explicitly say the speaker cannot charge a phone or reverse charge.

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

Price-to-performance is strong in most reviews, especially at sale prices, though some nuance appears when compared with the larger Boom 2.

Remote-style control is mostly app-based, letting users control playback, volume, EQ, lighting, and speaker settings from a phone.

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

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 outdoor features are unusually strong, including Buzz Clean, emergency alarm, voice amplifier, white noise, and safety utilities.

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 a weakness because the product lacks speakerphone functionality in the one review that directly addresses it.

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

Status feedback is adequate but not especially advanced, with battery bars, button lights, and app battery indicators mentioned.

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

Stereo imaging is limited from a single mono speaker but improves when two units are paired in TWS stereo mode.

Sustainability evidence is very limited and only tied to packaging that a reviewer called minimal plastic and recyclable.

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 consistently supported, though several reviews emphasize the port is charging-only.

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

Value for money is a major positive, especially at discounted prices, but some reviewers note tradeoffs versus the Boom 2 or more refined rivals.

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

Voice clarity for vocals is generally good, with multiple reviewers noting clear vocals or well-defined voices even with strong bass.

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

Water resistance is a standout, with IP68 waterproofing and saltwater resistance mentioned across nearly every review.

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

Weight convenience is strong; reviewers repeatedly call it compact, lightweight, backpack-friendly, or easy to carry.

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

Wired input is a clear limitation because reviewers repeatedly state there is no 3.5mm aux input and that USB-C is charging-only.